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Walmart US Digital STB Questions - Page 45

post #1321 of 1562
Quote:
Originally Posted by dogleg69 View Post

I have never seen one. I have seen a manual with a graphic showing the hdmi port. I do not think they were ever produced (but I do not know that for sure).

I tried a couple of those quick commands. They did not work on the 2.5.57 unit.
I also purchased another and it has 2.7.15 (2.4.18-7) Hdw. DB2020. It will not get any of the channels. Test was by swapping boxes. It eventually found channels, but no video, off air message.
I'm curious of the liklihood of a flash helping it? Right now I have the feeling the box may have a problem such as a weak tuner.

I followed some links to HiSense.com and saw they have a couple of interesting boxes. Translated by google. One of them, MC668HC, looks to be the same box as this with a different face plate. The other has a HDD and numerous outputs along with wireless and USB for loading with movies.

Also among links was one to ATI and their Xillion chip and Xillion mainboard. Following are those ATI say they shipped to: Coship Matsushita (Panasonic) TiVo
Funai (Sylvania) Philips Toshiba
Hisense Scientific-Atlanta Thomson / TTE (RCA)
Hitachi Samsung USDTV
JVC Sanyo Xoceco (PRIMA)
I can only wonder if these units have the Xillion chip and it would interest me to learn what boxes made use of the mainboard.
post #1322 of 1562
Quote:
Originally Posted by nthums1 View Post

I tried a couple of those quick commands. They did not work on the 2.5.57 unit.
I also purchased another and it has 2.7.15 (2.4.18-7) Hdw. DB2020. It will not get any of the channels. Test was by swapping boxes. It eventually found channels, but no video, off air message.
I'm curious of the liklihood of a flash helping it? Right now I have the feeling the box may have a problem such as a weak tuner.

Flashing won't hurt -- it may not help if indeed you have hardware troubles. The 2.5.57 unit will not respond to the .bin file on the FAT filesystem. You have to use a linux solution. However, there is a dd created windows file in the windows/usingPre_2.7.15 dir on www.mediafire.com/dogleg69. It is the 2.9.3 version. So, if you don't have access to linux, you can use the dd2.9.3 to upgrade to 2.9.3 and then upgrade to 2.9.5 using the .bin file.

Do you have linux access/experince? If so, you can upgrade both using the latest tar.gz file and the makekey script.
post #1323 of 1562
Quote:
Originally Posted by dogleg69 View Post

I have never seen one. I have seen a manual with a graphic showing the hdmi port. I do not think they were ever produced (but I do not know that for sure).

Quote:
Originally Posted by dogleg69 View Post

Flashing won't hurt -- it may not help if indeed you have hardware troubles. The 2.5.57 unit will not respond to the .bin file on the FAT filesystem. You have to use a linux solution. However, there is a dd created windows file in the windows/usingPre_2.7.15 dir on www.mediafire.com/dogleg69. It is the 2.9.3 version. So, if you don't have access to linux, you can use the dd2.9.3 to upgrade to 2.9.3 and then upgrade to 2.9.5 using the .bin file.

Do you have linux access/experince? If so, you can upgrade both using the latest tar.gz file and the makekey script.

My main concern is with the 2.7.15 box. I've had it disconnected for a few days, using the older box since it works, while I try to find the best solution.
I just hooked it up again and now it starts with a screen that says I must set it up. OK allows scanning of channels and it finds 9. Next screen pops to "USDTV service not found". And my only options are retry & adjust antenna. I'm stuck in that loop.
I don't know Linux. And now am clueless as to which would be the appropriate flash?
post #1324 of 1562
Quote:
Originally Posted by nthums1 View Post

My main concern is with the 2.7.15 box. I've had it disconnected for a few days, using the older box since it works, while I try to find the best solution.
I just hooked it up again and now it starts with a screen that says I must set it up. OK allows scanning of channels and it finds 9. Next screen pops to "USDTV service not found". And my only options are retry & adjust antenna. I'm stuck in that loop.
I don't know Linux. And now am clueless as to which would be the appropriate flash?


If the 2.7.15 box allows you to scan and then says USDTV service not found, that is good news -- it sounds like it is a subscription box. If it was working before, I have no idea how an FTA box jumped back to subscription unless the rollback sequence was initiated.

On the 2.7.15 box, here is what I would suggest:

- go to www.mediafire.com/dogleg69
- navigate to the windows --> archive directory
- download the fromService293.zip file
- unzip the file and follow the instructions inside the file
- try and use a 32mb usb stick (or something smaller than a 1gb)
- after the usb is made, unplug the box, stick the usb in the back, plug back in and follow on screen instructions

- if that works, you will have an FTA with 2.9.3 version.
- now download the latest usdtvUpdate295ForWindowsFAT.zip and follow the instructions in it to upgrade to 2.9.5

Sorry you have to go through two steps, but that is the easiest way with the software is posted. Let us know if it works or if you need any other help.
post #1325 of 1562
Quote:
Originally Posted by dogleg69 View Post

If the 2.7.15 box allows you to scan and then says USDTV service not found, that is good news -- it sounds like it is a subscription box. If it was working before, I have no idea how an FTA box jumped back to subscription unless the rollback sequence was initiated.

On the 2.7.15 box, here is what I would suggest:

- go to www.mediafire.com/dogleg69
- navigate to the windows --> archive directory
- download the fromService293.zip file
- unzip the file and follow the instructions inside the file
- try and use a 32mb usb stick (or something smaller than a 1gb)
- after the usb is made, unplug the box, stick the usb in the back, plug back in and follow on screen instructions

- if that works, you will have an FTA with 2.9.3 version.
- now download the latest usdtvUpdate295ForWindowsFAT.zip and follow the instructions in it to upgrade to 2.9.5

Sorry you have to go through two steps, but that is the easiest way with the software is posted. Let us know if it works or if you need any other help.

If rollback means toggling to the other whatever inside box, yes I toggled it.
How do I update that side of the unit?
I thought I was trying to update that part but instead did the 2.7.15 side to 2.9.3. That adds a bunch of diagnostic stuff, but have no idea what it means.

I'm reallly beginning to believe it has a hardware issue. When first plugged, you have to be about a foot away from box with remote. After it has been plugged for maybe half hour I can work back to a normal range. Possibly a voltage problem, so if anyone knows the voltages inside the unit that might be helpful. Otherwise I have to suspect the previous owner did not have his antenna system properly isolated or grounded. That is the front end, tuner section, took a static charge or lightning strike. He claimed he could no longer use it because a new wing on a hospital blocked his signal and had to go dish.
post #1326 of 1562
badda-bing.
Hardware indeed. I decided to check voltages and as luck would have it the voltages are printed on the PS board next to each pin of the two connectors. Voltages on the line going to tuner, 30V, 5V, & 3.3V. The other line going to MOBO also has 12V.
I notice what looks like 3 caps bulging. The voltages I read were 35V, 4.5V, & 3.0V. The 12V was close. But what alarmed me was that after holding the probe on the 30V line for a couple of seconds it would start to runaway and read 65V a couple of times. I switched to AC mode and saw that 65VAC was riding on the DC line. I was using a cheap meter and it is likely that the DC scale was reading that AC presence. Probably low power but certainly too much ripple for my thinking.
Dug and found some caps in my junk box (40 years old). I found one exact 470mf. One 500mf at about double the required voltage to replace one of the 470mf. And 1000mf at a much higher voltage as well. (higher voltage is OK. And likely they would not have failed if they had not been so cheap as to spend a couple of cents more per capacitor.)
I fired up and reread voltages. 30.0V, 4.9V, 3.3V, & 12.3V. I forgot to check for the ripple. Two of the caps were on the 5V line and one on the 3.3V, I think, or other way around. I have to assume the 30V line is controlled by the accuracy of either the 5V or 3.3V line. The other caps did not appear to have a problem. Also I noted the input voltage range for the PS board, 110-220V. I could have investigated further, but wanted to see the results so I closed and plugged.
Remote function immediately and it tuned all channels. Hoo-ray!

I did make some notes of what else was inside. On the mainboard is a connector labled SmartCard. Also a designation for a connector that had a lot of pins, but not present. And a four pin connector near the CPU. And an eight pin connector at the rear of the board next to the S-video connector. Seems that one was definitely meant for a port out the back. It would be interesting to learn what they were intended for. To add the smart media would be very easy if the software is accomadating and there is need. The same with the other two connectors. Only eight pin that comes to mind, out the back, might be 4 twisted pair, LAN, or possibly a sort of com port. checking the module on my 42" monitor I see they only have 8 pins in the 9 pin connector. The manual shows 2 pins N/C and 2 pins shorted. Maybe someone more familiar with COM ports can chime in.

Now as to function using the 2.9.3 version. The older one has only one zoom and it widens the picture which works for near all of my situations where the station is broadcasting a program in something other than full. The 2.9.3, zoom1 increases vertical, and zoom2 keeps the vertical increase and increases horizontal. I seldom need the vertical increase. And I've never seen a difference between auto-aspect and full. So what does auto-aspect do?
And is it possible to flash that second part of box?
post #1327 of 1562
Quote:
Originally Posted by nthums1 View Post

badda-bing.
Hardware indeed. So what does auto-aspect do?
And is it possible to flash that second part of box?

Wow. That is incredible. Nice job on find and more incredibily fixing the box. I must tip my hat to you.

It is possible to flash the box. There are two sets of NAND flash chips. One holds the active software, the other is for rolling back or upgrading. So, give the 2.9.5 a try as it fixes quite a few issues. If for some reason you want to go back to 2.7.15 or whatever, we can work and make that happen.

Again, great fix. Thanks for posting the details.
post #1328 of 1562
Quote:
Originally Posted by dogleg69 View Post

Wow. That is incredible. Nice job on find and more incredibily fixing the box. I must tip my hat to you.

It is possible to flash the box. There are two sets of NAND flash chips. One holds the active software, the other is for rolling back or upgrading. So, give the 2.9.5 a try as it fixes quite a few issues. If for some reason you want to go back to 2.7.15 or whatever, we can work and make that happen.

Again, great fix. Thanks for posting the details.

I thank you and this forum for the information that led me to believe my situation did not fit the normal problems of most. I'm an old tech/engineer, so the warming up of the box allowing the remote to work was indicative of something electrical, just as it getting too warm can cause it to die.

In my searching I have found some indication that this box might have some multi-path tuning capabilities. But the timing might be set a little too close for all situations, but then situations can vary widely. It seems I'm a victim of the multi-path from transmitter. The indication seems to be the indicator signal strength. Even though I may show a peak signal, as the max setting for this is approached, the signal will suddenly drop to near zero and sometimes drop picture for an instant and then the signal meter returning to max. By carefully aiming I am able to stop near all of it. But time will tell as these signal paths can change between day and night. That brings in the decision of what is better antenna since there are a few degrees between the two transmitter sites, about 30 degrees I think. A higher gain/tighter beam might eliminate the side and reflected lobes, but then it might also mean having to turn antenna everytime I switch between them. And still I have the wait until they finalize digital. Right now I have one upper VHF that is transmitting digital on UHF. One they shut the analog down, they will move the digital back to channel 11. Lower frequency generally means transmitting farther with less power. And then I have no idea what PBS is doing, analog 9. If they are transmitting digital, I can not find them but there has also been some comment that they are doing low power until the analog shutdown. Another wait and see, which may put me in the trouble others have been having trying to get PBS.
What I would like to do is flash the nand that is useless now. It apparently was never flashed for FTA and is in the USDigital state.
post #1329 of 1562
Update, other box. My curiosity about those unused connector and other points forced me to grab the disconnected box and peak inside, the other box.
First, I notice it has a bulging capacitor, one of the same ones as the first box. Also the big capacitor that is near the front of regulation, 68MF, 400V, looked like it might have slight bulge. I'm beginning to think that if I want to keep boxes long term, it might be time to visit a store and replace all the caps on the power supply, or least the bigger ones. And bump the voltage of the replacements maybe 50%. I would think the capacitance would be enough since this PS was also designed for countries using 220V and most of those use 50HZ I think. Since 50HZ is harder to filter to smooth DC, the capacitance should be enough for 60HZ. But then maybe they restricted them to 60HZ only countries. The back plate info, 120V 60HZ might mean that it is equipped with 110V plug for 60HZ, and in different country the backplate might change with the cord and plug. I did not note a specified frequency on the PS board.
post #1330 of 1562
Concerning my connector curiosity.
Aware of a place for a connector at the back, I was hoping for an additional video option such as HDMI or DVI. What I learned of the eight pin holes for the connector is that the first three would be tied back to the Component RCA jacks in existence. Also one of the pins would carry 5V. Two of the connections I was not able to determine, but the last two end up under the CPU and presumably are connected. Can anyone make sense of what type of connector would be used and possible signalling?
My best guess presently is a VGA which only needs 7 leads for signal plus ground. Also RGB would need to be output rather than Y, Pb, Pr. It would seem that RGB would be preferred since it is wider bandwidth of the two. But then I don't know what is exactly carried with digital transmission or should I say how. I know the analog version front to back. And once you achieve a RGB signal it is senseless to convert back the other way unless you have bandwidth constrictions.
Does anyone know if this box is capable of outputting RGB, presuming someone can write the code to switch it. I'd love to compare RGB vs. the current Y,Pb, Pr. That switch would use the same connectors already present on the back.

I also looked more closely at the spot for a connector that looks to be a direct connection to CPU for near all pins. It is an 80 pin connector. I have no idea what this might have interfaced since the double row is only about 2" long.

But the location near the SmartCard connection, a 10 pin, appears to be for serial interfacing. One pin controls a buffered logic gate. I did not follow output yet. Other than ground, the remaining pins connect a 1Mb flash memory serial interface. One of those is a select which presumably designates which of the four pages of memory to use. Another line is the serial data in, and the other a serial data out.
post #1331 of 1562
Update concerning size of capacitors. A higher voltage rating is good as long as it does not get so physically big that it becomes impossible to fit it. As to using a capacitor of a larger value, I will have to do some more research. I just remembered the coils of wire that were located near those final capacitors. I had not done a trace of the connections, but it just occurred to me that they may be part of a "L" or "Pi" filter. Unfortunately, it is likely I will not be able to determine the inductance of them to calculate the exact frequency such a circuit is meant for. Once I have time to determine the circuit diagram I will have a better idea of the exact function. It might be a low pass filter effectively killing any ripple, especially 60HZ. It might be a trap effectively sending 60Hz to ground. Until I know the exact circuitry and function it would be best to stick with the exact capacitance. Changing the capacitance would detune the trapping or passing circuitry from its current design. But I would recommend using a higher voltage at this time because judging from my two boxes, there is a design weakness on the PS board. I would recommend upping the voltage spec by at least 50%. That is the cap marked 10V should be at least 15V and those marked 16V should be at least 24V and so on. As a rough figure, 50% used to be the recommended amount. The voltage of the caps I replaced should have been sufficient for the 5V and 3.3V line they were on unless there was a large amount of ripple they were having to deal with, such as the 60+VAC noted on the 30V output.
More after I get the circuitry design.
post #1332 of 1562
I was almost ready to throw out my old USDTV Hisense box, when I came across this thread. I did a bunch of reading, and even prepared my own USB dongle to upgrade the firmware.

I plug in my USDTV box for the first time in months, and nothing happens. Both lights are steadily flashing green, with a small beeping noise coming out of the speakers. I try the USB dongle (unplug unit, plug USB stick in, plug in unit), but all I get are both green flashing lights.

I read earlier that it may be a power source? Is this still the case? Or are there any other options?

If it turns out a $20 power source is needed, then why would I want to sink money into the Hisense, when I can take my $40 credit (from the government) and buy a new box? Is it the menu that makes the Hisense so popular?

Thanks for any advice you can give me.
post #1333 of 1562
Quote:
Originally Posted by bullitt22 View Post

I was almost ready to throw out my old USDTV Hisense box, when I came across this thread. I did a bunch of reading, and even prepared my own USB dongle to upgrade the firmware.

I plug in my USDTV box for the first time in months, and nothing happens. Both lights are steadily flashing green, with a small beeping noise coming out of the speakers. I try the USB dongle (unplug unit, plug USB stick in, plug in unit), but all I get are both green flashing lights.

I read earlier that it may be a power source? Is this still the case? Or are there any other options?

If it turns out a $20 power source is needed, then why would I want to sink money into the Hisense, when I can take my $40 credit (from the government) and buy a new box? Is it the menu that makes the Hisense so popular?

Thanks for any advice you can give me.

The $40 you got from the government is for a converter box, that is a box that will tune HD and output Standard Definition. The Hisense box will accept HD signals and output standard or HD signals over component outputs. It's also much higher quality than the converter boxes, which are built to last only a year or two. To get a decent HD tuner you'd need to spend well over $100. Another side note, most converter boxes are composite only, no s-video. I'm using the s-video output on my hisense box and it's crystal clear! I just ordered another box for our downstairs tv, I can't wait to upgrade it. Thanks dogleg69!
post #1334 of 1562
Quote:
Originally Posted by bullitt22 View Post

I was almost ready to throw out my old USDTV Hisense box, when I came across this thread. I did a bunch of reading, and even prepared my own USB dongle to upgrade the firmware.

I plug in my USDTV box for the first time in months, and nothing happens. Both lights are steadily flashing green, with a small beeping noise coming out of the speakers. I try the USB dongle (unplug unit, plug USB stick in, plug in unit), but all I get are both green flashing lights.

I read earlier that it may be a power source? Is this still the case? Or are there any other options?

If it turns out a $20 power source is needed, then why would I want to sink money into the Hisense, when I can take my $40 credit (from the government) and buy a new box? Is it the menu that makes the Hisense so popular?

Thanks for any advice you can give me.

Because none of those coupon boxes will give you HD. They only give you an SD picture, that is 480i. The best output I've found on those that qualify for the coupon is S-video. I tried a Phillips recorder and it had an SDTV tuner only with outputs up through HDMI. I get a far better picture with this Hisense using component than what that box gave with its upconversion to 1080p on HDMI. I glanced around and tuners that do true HD and with features similar to this one are in the $150 -250 range.
I did finally learn that Sony boasts an HDTV tuner, but they do something stupid by my thinking. I called their tech support and they contacted engineering. I actually had two questions, but the answer to the second made the first moot for my purposes. I think I wanted to know about time-shifting and apparently the Sony don't do that. The other was if the Sony actually output the HD signal because there were notes concerning playback, that it did not. Because the recording formats of DVD and HDD at that time were such that you could not compress HD enough to record it, instead of sending the HD through the box when you were listening live, they processed it down to SD so that it was recordable and at that point split for output. Dumb huh? Even though the box I was looking at was upconverting to 1080p, no matter how good the upconverting is you just can't recreate the real signal from 480 or 720. If it was only changing 1080i (HDTV) to 1080p they should be able to get pretty close by combining alternate frames. But there is no way they could accurately fill in all the missing pixels from 480 or 720 to stretch the picture all the way to 1080.
MPEG4 has been around a little while, but it is hard to find any box that uses it for the recording format. It allows greater compression with less loss.
I have assumed the set you hook to has a great picture, capable of better than 480i.
post #1335 of 1562
Dogleg, I'm stuck as to how I'm going to flash to FTA with a Linux file. The one that seems like it would work on the never flashed ROM requires Linux to format the stick.
How do I proceed?
post #1336 of 1562
Quote:
Originally Posted by nthums1 View Post

Dogleg, I'm stuck as to how I'm going to flash to FTA with a Linux file. The one that seems like it would work on the never flashed ROM requires Linux to format the stick.
How do I proceed?

Remind me again about the box you want to upgrade. What version is currently running on it? Look on the System Info screen.
post #1337 of 1562
Quote:
Originally Posted by dthibode View Post

The $40 you got from the government is for a converter box, that is a box that will tune HD and output Standard Definition. The Hisense box will accept HD signals and output standard or HD signals over component outputs. It's also much higher quality than the converter boxes, which are built to last only a year or two. To get a decent HD tuner you'd need to spend well over $100. Another side note, most converter boxes are composite only, no s-video. I'm using the s-video output on my hisense box and it's crystal clear! I just ordered another box for our downstairs tv, I can't wait to upgrade it. Thanks dogleg69!

Ah - OK. Looks like I have a good box then.

So, back to square one. I can't even get it to turn on (after not using it for a few months). Both lights on the front just blink on and off. Is my best option at this point to look at a new power box? Can I open it up and do a hard reset of some sort? It doesn't seem to respond to the remote reboot sequence.
post #1338 of 1562
Adding more detail...

The Signal and Power lights are both simultaneously flashing green, fairly rapidly. I have opened the case, and I do not see anything that appears burnt. I unplugged some main motherboard wires in the hopes it would reset something.

I have tried the remote reset functions, and those are not working either (new batteries in remote).

Anyone have any ideas?
post #1339 of 1562
Quote:
Originally Posted by bullitt22 View Post

Adding more detail...

The Signal and Power lights are both simultaneously flashing green, fairly rapidly. I have opened the case, and I do not see anything that appears burnt. I unplugged some main motherboard wires in the hopes it would reset something.

I have tried the remote reset functions, and those are not working either (new batteries in remote).

Anyone have any ideas?

Blinking double green lights indicate a bad power supply. There is no hardware reset (like a jumper or anything) that I know of. The only place I know of is http://www.proserv1.com/ --> Contact Us (in the middle of the page). Rough website, but this is the original marsman website. I have no idea what he would charge.

If I had one you could have it, but smintn had a box that blew up and I thought I had an extra PS for him. Turned out I did not. I would try marsman and report back. OR ask for hardware debugging help here if you are good with a multimeter and soldering iron.
post #1340 of 1562
Quote:
Originally Posted by dogleg69 View Post

Blinking double green lights indicate a bad power supply. There is no hardware reset (like a jumper or anything) that I know of. The only place I know of is http://www.proserv1.com/ --> Contact Us (in the middle of the page). Rough website, but this is the original marsman website. I have no idea what he would charge.

If I had one you could have it, but smintn had a box that blew up and I thought I had an extra PS for him. Turned out I did not. I would try marsman and report back. OR ask for hardware debugging help here if you are good with a multimeter and soldering iron.

Thanks for the info. I have emailed marsman.

I am confused, though, as to "power supply". Normally I think of a power supply as a cord with some sort of large box inline. When I open this USDTV box up, the power cord goes right into the motherboard, 2 wires - no box or inline fuse. So, what exactly does the power supply consist of? Just the cord? Or is there more to it?
post #1341 of 1562
I'm a recent new owner of one these boxes, the Hisense HDTV tuner, and it looks to me by the trend of quite a few posts here that the Hisense box suffers from the "Bad Caps" plague. Read about what I'm talking about on Wikipedia, the article titled: Capacitor plague.

On that Wikipedia page they also have a picture showing what a typical internal "power supply" looks like. Power supplies can be external boxes on the power cord outside the box (typical of laptop PCs) or they can be on printed circuit boards inside, as the Hisense box has.

My PC purchased in 2003 had bad caps, and I replaced them all myself successfully and got the mother board (and PC) to work again. I might suggest there are web sites (some are mentioned in the Wikipedia article) that will sell you a set of replacement caps relatively cheap. As I recall, I purchaed about 8 for my PC resurrection project for about $12.

My advice would be when replacing caps, use the same capacitance value and voltage as the originals. Although there's nothing wrong with going to a higher voltage, they would be more expensive, and it's probably not necessary. It's very unlikely the originals failed due to improper specs, and more likely they were defective due to the "Capacitor Plague".

-Norm
post #1342 of 1562
Quote:
Originally Posted by bullitt22 View Post

Adding more detail...

The Signal and Power lights are both simultaneously flashing green, fairly rapidly. I have opened the case, and I do not see anything that appears burnt. I unplugged some main motherboard wires in the hopes it would reset something.

I have tried the remote reset functions, and those are not working either (new batteries in remote).

Anyone have any ideas?

Since you have it open, did you look for bulging capacitors. It is possible that they were going bad when you last used it and the pressure inside the capacitor might have forced the electrolyte out of the cap. Look on the board at the base of the capacitors. Or use a meter to check the voltages. How long had it been since you used it?
I would have to look at the spec for the Flash chips as they do have a limit on the memory, but I think it was around a year minimum.
Maybe reflashing will do it.
post #1343 of 1562
Quote:
Originally Posted by dogleg69 View Post

Remind me again about the box you want to upgrade. What version is currently running on it? Look on the System Info screen.

It is the second memory in the box that has the 2.9.3 upgrade. I can't get at that part of it because when it boots it wants to do the setup and I can't get out of that sequence because it finds no USDigital channels. Only options are adjust antenna and retry. So I end up doing the toggle back to the other memory.
Does anyone know how USDigital coded their transmission? How different was it from the current ATSC ?

I've seen some questions about adding CQAM and NTSC. I too am interested in that and it seems it should be do able. I don't know the differences between the NTSC and ATSC tuners. The NTSC does have a wider reception bandwidth though because frequencies for channels 2 - 6 are not used with digital. There are a large number of video cards that have tuners on them and some of them will do all three type of signals. Guessing, I suspect there is circuitry that digitizes the output of NTSC tuner where they actually have two tuners on the board, two RF inputs. We might be lucky and find a tuner that would directly swap with the one on the current board. The next time I have a box open, I'll check the voltages at the tuner can and see if that 30V line is actually fed to it. It is possible it is stepped down on that circuit board or used for something else on the board. There is no 30V used in computers.
Does anyone know a tech that works in a repair shop that does recorders with tuners? They might use 30V.
I suspect that to get CQAM it is just a matter of programming the chip. And as to QAM, let's face it, the signal is there. You just need to find the key.
post #1344 of 1562
Quote:
Originally Posted by norm1968 View Post

I'm a recent new owner of one these boxes, the Hisense HDTV tuner, and it looks to me by the trend of quite a few posts here that the Hisense box suffers from the "Bad Caps" plague. Read about what I'm talking about on Wikipedia, the article titled: Capacitor plague.

On that Wikipedia page they also have a picture showing what a typical internal "power supply" looks like. Power supplies can be external boxes on the power cord outside the box (typical of laptop PCs) or they can be on printed circuit boards inside, as the Hisense box has.

My PC purchased in 2003 had bad caps, and I replaced them all myself successfully and got the mother board (and PC) to work again. I might suggest there are web sites (some are mentioned in the Wikipedia article) that will sell you a set of replacement caps relatively cheap. As I recall, I purchaed about 8 for my PC resurrection project for about $12.

My advice would be when replacing caps, use the same capacitance value and voltage as the originals. Although there's nothing wrong with going to a higher voltage, they would be more expensive, and it's probably not necessary. It's very unlikely the originals failed due to improper specs, and more likely they were defective due to the "Capacitor Plague".

-Norm

There may have been an extra bad batch, but my years of experience say it is more than that. I worked TV in late 70's. This was the period of transition to mostly solid state, but occaisonally I'd see one of those early 50's round picture tube sets. Going back to that time frame, you might say every component on them was discrete. Tons of parts. And power was derived from a transformer that weighed maybe thirty pounds and had multiple windings for each required voltage. The beauty of the transformer was that it made the system very tolerant of surges, spikes, and lightening strikes, as long as it was not a direct strike. The reason for these old sets still existing, mostly RCA, was they built them like a Gulfstream, more than they had to be to meet minimums.
Through time most manufacturers have adopted a close to minimum approach to hold cost down and maybe a bit of GE philosophy, the father of planned obsolescence.
And as we moved into the solid state and integrated circuits, there were many design weaknesses. One of the major ones was they did not design in a way to overcome the replacement of the costly power transformer. Silicon just can not take those huge spikes that transformers and vacuum tubes could then. Today we have surge suppressors to help.
But capacitors, they have cut them to the minimum because of cost. You have not lived until you have your face inside a set and one of those electrolytics explodes. A medium sized one sounds like a shotgun. And that can is filled with foil that can spread confetti into your face.
An example of how close they are cutting the tolerance, look at the caps on the board of this unit. You will find two caps of equal value but one is rated 16V and the other is 10V. It would be my guess they came down the same assembly line but when tested at the end, the 10V was weaker than the 16 for the voltage test. They both would have been within capacitance spec, so they sold the 10V at a slightly lower price, maybe $15 per 100. Design engineers pick from ready made components when possible because they are cheaper than special order and if they have orders to pick price or end quality, they go with the cheaper part when possible. We, having to buy retail, will likely pay a bit more than the 15 cent difference, maybe 60 cent. So I ask, for a bit more money, do you want that extra margin of reliability the company did not put in?
It is likely you will not see a significant increase in price for any of the capacitors on this board by doubling the voltage spec, unless it ends up being an un-common value.
If we were looking at say a 4700MF at 1000V and chose to go to a 1600V, then I'd expect to pay a few more dollars. I think the biggest cap I saw was 68MF at 450V. 68MF, not the voltage, sounds uncommon to me and you might pay a bit more for it. Unless you happen to find one of those bag of parts for a few dollars. They quite often have a few common capacitors and then some of those un-common ones because of overstock.
I hesitate to say it would be OK to increase the capacitance to a more common cap of 100MF without knowing the circuitry it is used in, but do not hesitate to increase voltage, especially at the front of the board circuit-wise. That is where power is fed in and you are susceptable to anything on the line.


BTW, lightening suppressors, surge suppressors, and UPS are not 100%. All have a reaction time before clamping and in those few nano seconds it may be too late. Isolation transformers are stil one of the best means of protection, but costly.
post #1345 of 1562
Quote:
Originally Posted by bullitt22 View Post

Thanks for the info. I have emailed marsman.

I am confused, though, as to "power supply". Normally I think of a power supply as a cord with some sort of large box inline. When I open this USDTV box up, the power cord goes right into the motherboard, 2 wires - no box or inline fuse. So, what exactly does the power supply consist of? Just the cord? Or is there more to it?

It is really quite simple, That box you are thinking of, well it is a bit larger and they stuffe the motherboard and tuner board in it as well.
That first board you came to that had the power cord attached, that is the PS board. At the opposite end you will find two connectors and alongside of them you will see the output voltages marked.
If you start disconnecting these plugs, be careful as not all of them have a plug at both ends. I think the tuner board is soldered on one of the connectors. Look closely and you will see a slight difference, mostly in the height.
post #1346 of 1562
First-time post - actually, not quite my first but forgot all of my earlier login info from previous incarnations.

Anyway, I rejoined just to add to the chorus. I just received my box from Mike (Ebay: emma71803) and my box also had the most recent firmware 2.9.5.

It came with all of the cables I needed and a pretty decent RCA universal remote as well. Without looking at a manual of any kind, setup was a snap and the picture and sound quality is terrific. Thanks to everyone at this forum (and google's search capability) for the great info!
post #1347 of 1562
Quote:
Originally Posted by bullitt22 View Post

Thanks for the info. I have emailed marsman.

I am confused, though, as to "power supply". Normally I think of a power supply as a cord with some sort of large box inline. When I open this USDTV box up, the power cord goes right into the motherboard, 2 wires - no box or inline fuse. So, what exactly does the power supply consist of? Just the cord? Or is there more to it?

There are 4 components inside the USDtv box:

1. Main/motherboard (contains the ATI Xilleon chip, flash, etc...)
2. ATSC Tuner
3. Power Supply Unit
4. On/off and lights

The PSU does have the cord as well as the circuit board to feed the main board and the tuner. If you got one, you would have to disconnect the ribbon cables and replace the PSU.
post #1348 of 1562
Quote:
Originally Posted by nthums1 View Post

It is the second memory in the box that has the 2.9.3 upgrade. I can't get at that part of it because when it boots it wants to do the setup and I can't get out of that sequence because it finds no USDigital channels. Only options are adjust antenna and retry. So I end up doing the toggle back to the other memory.

I'm still confused to which software is running right now. We don't have to worry about what is on each NAND flash. I just need to know which one is active and the software that is on the active when you boot.

If you boot right now and it asked you to scan for USDtv channels, then you are booting with subscription software. So, we need to get that to FTA.

- go to www.mediafire.com/dogleg69
- navigate to the windows --> archive directory
- download the fromService293.zip file
- unzip the file and follow the instructions inside the file
- try and use a 32mb usb stick (or something smaller than a 1gb)
- after the usb is made, unplug the box, stick the usb in the back, plug back in and follow on screen instructions

- if that works, you will have an FTA with 2.9.3 version.
- now download the latest usdtvUpdate295ForWindowsFAT.zip and follow the instructions in it to upgrade to 2.9.5


If you are already running 2.9.3, then just do the last two steps.
post #1349 of 1562
Dogleg69 or anyone else, I have a question. I bought another tuner off Ebay and the guy said he tested it with component out and it worked fine. When I power it on with composite I get nothing, just a black screen. How do I switch it back to regular outputs without seeing the menu? Thanks!
post #1350 of 1562
Quote:
Originally Posted by dogleg69 View Post

There are 4 components inside the USDtv box:

1. Main/motherboard (contains the ATI Xilleon chip, flash, etc...)
2. ATSC Tuner
3. Power Supply Unit
4. On/off and lights

The PSU does have the cord as well as the circuit board to feed the main board and the tuner. If you got one, you would have to disconnect the ribbon cables and replace the PSU.

OK - thanks for the explanation. I have pulled the PSU out and carefully examined it. I don't see anything burnt, leaking, blown, etc. If the PSU went out, would I see something? Or could it be something I don't see?

I guess I am hesitant to spend $15 on a new PSU when it might be something else. Should I solder in a new fuse? It doesn't look blown, but it might be in the corner, under the metal part that I can't see?

Or, could it be that I used to have it hooked up via component, and am now using composite? Is that why I don't see anything on the screen? Though, I still wouldn't think that both lights on the front would be rapidly flashing green...
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