DigitalStream DTX9950 - Page 11 - AVS Forum | Home Theater Discussions And Reviews
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post #301 of 325 Old 10-23-2012, 08:21 AM
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FYI: There are no 3 MW transmitters on Mt Wilson...FCC max in UHF Band is 1 MW (1000 kW):
http://www.fccinfo.com/CMDProFacLookup.php?sCurrentService=TV&sKilometers=5&sLatitude=34-13-37&sLongitude=118-04-00&tabSearchType=Within+Search

And being at about 6000-ft elevation, it provides strong signal coverage except in a few canyon locations.
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post #302 of 325 Old 11-04-2012, 09:35 AM
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Hello,

I have a Digital Stream DTX9950 with what seems to be a bad logic board. After reading some posts here and elsewhere I tried replacing the 470uF 10v cap with a 470uF 16v (big brown one at the front of the second photo below), but no luck. I happen to have a second DTX9950 that is working, so I tried swapping the power supply boards. Both boards are functional; the "repaired" power supply board worked fine in my working DTX9950.

When I power up in the faulty DTX9950, the red "standby" light comes on, as usual. I can turn it on by pressing the power button on the box itself or by using the remote. The red light changes to green, but all I get on the TV is snow (whether I use the RCA or RF output). I cannot turn it off again (green to red) without unplugging it from the power outlet.

Has anyone seen this? Is there a reasonable fix? All of the capacitors and chips look OK and the board passes the sniff test.

This behavior began after a power outage (just your run of the mill power outage AFAIK, not a lightening storm). Both boxes were plugged in and only one died.

Thanks.

Andy



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post #303 of 325 Old 12-30-2012, 07:26 PM
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The last unreplaced NTSC-only television in our house, in a location where TV is rarely watched any more (and therefore still unreplaced), is connected to a DTX9950.

A few days ago I turned it on to get a new subchannel into the table and noticed that the remote wasn't working; one battery had corroded.  I replaced the batteries, but the remote had been without power for so long that it had lost the programming for operating the television.  By some miracle I located the manual and thus could reprogram it.

Guess that's something to check on every couple of years, huh?  The DTX9950 and the television are still working.

How long should the remote be able to go without power before it forgets the TV code setting?
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post #304 of 325 Old 12-31-2012, 09:50 AM
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My inexpensive Philips u-remote manual states 5 minutes for a battery change.

I had to go through my Mom's house and check all the battery-operated stuff, been in devices for years and years with flashlights and such basically ruined.

I learned I could pop the battery cover and smell them to tell if they're on their way out before they get destructive. Hey I've got some of those little LED flashlights that use 3 AAA batteries, something about the nature of their current draw one battery goes completely dead while the other two are still good; the bad batteries even corroded/exploded a bit and they weren't even that old, just drained. I had a battery explode in a remote once, heard a pop and then it smelled bad (it's not a huge explosion).

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post #305 of 325 Old 12-31-2012, 11:55 AM
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Quote:
Originally Posted by Floydage View Post

My inexpensive Philips u-remote manual states 5 minutes for a battery change.
If that's also the case for the DTX9950's remote, it was more than five minutes from the time I found the problem until I replaced them, let alone the time that had gone by already since the batteries died.
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post #306 of 325 Old 01-04-2013, 09:23 AM
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Deja vu. I recently had two u-remotes lose their memory due to weak batteries although they still lit up the action LED. Seemed like it occurred when pushing a button, probably pulled the voltage too low (although that seems too short a period of time). The batteries also measured OK with my voltmeter but it looks like the real test needs to be done under load conditions (I guess those consumer battery testers do that?); not enough Coulombs left. One battery had a stinky and corroded negative terminal.

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post #307 of 325 Old 02-25-2013, 05:22 PM
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Quote:
Originally Posted by dattier View Post


It would be really surprising if the button on the remote had any effect while the unit is off.  Surely while it's off, either
  • passthrough is off
  • passthrough is on
  • passthrough remains however it was set when the box was turned off.


I need help, when I press the A/D button to turn off the DS 9950 the the signal from the DVD player plays correctly for about 5 seconds while the LED is blinking, then it goes to RED (standby mode) but no signal from the DVD.

Everything is connected correctly I just can't get the ds9950 to stay in the pass-through mode permanently, only for a few seconds.

How do I fix this, I just can't crack it, thanks

Dan
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post #308 of 325 Old 03-04-2013, 04:08 AM
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Quote:
Originally Posted by CasualOTAer View Post


[1] Have you tried setting the output preference to "RF" or ch3/ch4, then use the line-out connections with it set that way?

[2] I assume you know that most folks run the CECB volume at or near full, and adjust the TV volume to taste.


 

 

[1] Hey, what do ya know...  The volume is a little louder.  Why is that?

 

[2] Yep.  20


- Pj
Awaiting delivery of CalMAN Kit. Vizio P-Series - 2014 P502ui-B1E (50") TV - Firmware: 1.1.19. Win7Pro & FireFox 38.0.5, Desktop Computer. ClearStream-4 Antenna, a dying DTX9950 Converter Box (See www.BadCaps.Net and Capacitor Plague), Philips 3576H DVR, Philips 19PFL3403D TV. My brother: Android-driven Sony 75X850C TV & now has M401i-A3.
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post #309 of 325 Old 03-04-2013, 08:26 AM
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Quote:
Originally Posted by CleCakYngMfd View Post

[1] Hey, what do ya know...  The volume is a little louder.  Why is that? 

I don't have one of these models but based on the models I do have I'd say it's putting out mono in RF mode, hence no longer stereo. I think they do that for hooking up one of the line outputs to a mono TV (I do that with my little 13" kitchen TV).

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post #310 of 325 Old 03-04-2013, 03:52 PM
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Quote:
Originally Posted by Floydage View Post


I don't have one of these models but based on the models I do have I'd say it's putting out mono in RF mode, hence no longer stereo. I think they do that for hooking up one of the line outputs to a mono TV (I do that with my little 13" kitchen TV).

 

Ok, it is just masking the low-volume problem.   Anybody: No adjustable audio pot? 
 

Now, this other problem I have:

 
I have found this crazy problem of signal levels dropping to 0 and then back up again, all by itself.  It is somewhat rare, but I did witness one time while I had the meter onscreen and actually saw the signal level crash to 0!

 

When grabbing and slowly wiggling the coax/RF connector, the audio blanks-out in just a fraction of a second, with video breakup.  I just tried it with WRLM with a signal level of 60.   Wiggling the coax/RF connector, I got the level to drop into the 30s/40s with video blocking/breakup. 

 

I had this box apart and looked for a 'bad' solder joint some time ago.  Did not see anything obvious.  I will look at it again someday. 

 

I believe this problem existed since day one.  At first, I thought it was the connector or coax.  After swapping the RG6 cable and then replacing coax connectors, the problem remains.  It is definitely this DigitalStream DTX9950.

 

 

 

 

 

 

.


- Pj
Awaiting delivery of CalMAN Kit. Vizio P-Series - 2014 P502ui-B1E (50") TV - Firmware: 1.1.19. Win7Pro & FireFox 38.0.5, Desktop Computer. ClearStream-4 Antenna, a dying DTX9950 Converter Box (See www.BadCaps.Net and Capacitor Plague), Philips 3576H DVR, Philips 19PFL3403D TV. My brother: Android-driven Sony 75X850C TV & now has M401i-A3.
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post #311 of 325 Old 03-05-2013, 10:32 AM
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All the converter boxes I've dealt with have plenty of volume. Have you tried other audio sources?

I had a TV with flaky reception/connector like that, the coax might have gotten yanked; I touched up all the solder joints in the tuner section, especially the RF connector, and it fixed the problem.
Now if you're using a portable antenna and have reception issues you could be changing up the reception every time you contact the connector.

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post #312 of 325 Old 03-07-2013, 02:40 AM
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Quote:
Originally Posted by Floydage View Post

[1] All the converter boxes I've dealt with have plenty of volume. Have you tried other audio sources?

 


 

[2] Now if you're using a portable antenna and have reception issues you could be changing up the reception every time you contact the connector.

 

 

 

 

[1] Yes. It's the converter box's low volume output. It is now a little louder, close to normal, but now mono.

 

[2] The ClearStream4 is really an outdoor antenna. I have it about 8 feet away from the 9950 in a closet. The problem is for sure with the DS DTX9950.

 

I will have to reopen the 9950 one day and find that bad solder joint or perhaps a hairline circuit trace crack. Anyway, it is mostly OK if I don't bump it.


- Pj
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post #313 of 325 Old 03-07-2013, 08:33 AM
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Sounds like you got a flaky one. I'd be tempted to re-reflow all the solder joints with a heat gun or hair dryer but that can be dangerous, especially if it's a double-sided component board. If you spot touch-up the RF connector you might do the same to the other connectors - those and shields, big chunky stuff, and some stuff grounded are harder to get good solder flow during the reflow process. Poor connection on the line-out connectors could result in improper impedance and cause the audio problem akin to using crummy cables.

Nice editing! smile.gif

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post #314 of 325 Old 04-26-2015, 10:27 PM
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It appears the bad capacitor (cap) issue has recently made itself known to my DTX9950.
No image. Green LED stays on. No response with On/Off buttons on box or remote.

The only way I get it going again is to remove cover and use a hot air gun. This warms-up
the problem cap(s) and then I have to plug/unplug rapidly to get the LED to be Red. Then
it operates ok, until the room temp falls to 67 or 66 and below.

For now, I have the top vents blocked to keep it warm enough inside the box.

I shall attempt a cap(s) replacement and report back here.

It is one or more caps? Which one(s) exactly? I'm searching.


(See www.BadCaps.net)



Search words:

"How to fix"

"How to Repair"

"Converter Box"

"DTV Converter Box"

"Digital Converter Box"

"Digital TV Converter Box"

DigitalStream

"Digital Stream"

DTX9950

"Power Supply"

"DC Power Supply"

PS

"Bad Capacitor"

"Bad Capacitors"

"Hot Air Gun"

"Hair Dryer"

Solder

Flux

'Flux Capacitor' - Just kiddn'




.




- Pj
Awaiting delivery of CalMAN Kit. Vizio P-Series - 2014 P502ui-B1E (50") TV - Firmware: 1.1.19. Win7Pro & FireFox 38.0.5, Desktop Computer. ClearStream-4 Antenna, a dying DTX9950 Converter Box (See www.BadCaps.Net and Capacitor Plague), Philips 3576H DVR, Philips 19PFL3403D TV. My brother: Android-driven Sony 75X850C TV & now has M401i-A3.
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post #315 of 325 Old 04-27-2015, 10:15 AM
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Huh, I wonder if these are structurally similar to the Zenith/Insignia boxes? A poster over yonder Zenith MB has pretty much the same problem and they appear to be certain mfgering lots. Unfortunately he hasn't come across a solution though power supply caps are the prime suspect.

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post #316 of 325 Old 04-28-2015, 03:18 AM
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Quote:
Originally Posted by Floydage View Post

Huh? I wonder if these are structurally similar to the Zenith/Insignia boxes?

A poster over yonder Zenith MB has pretty much the same
problem and they appear to be certain manufacturing lots.

Unfortunately he hasn't come across a solution
though power supply caps are the prime suspect.


Poor quality capacitors in numerous devices over many years - and it is still ongoing. Read about here, at BadCaps.Net about how it started. (There's a list of 'bad' manufacturers based on user input.) CapXon, just to name one. Someone named this as, "Cap-Gate".

I have repaired a Vizio 322 plasma TV's Power Supply - bad caps. Numerous stories here on AVS Forum about PS problems with various brands of TVs and no doubt other equipment.

From what I have read here on AVS, the converter boxes were overall made on the cheap - so no surprise that a number of these boxes are going have some of these caps 'dry up' and fail. If I recall correctly, one poster says the Digital Stream DTX9950 has gone through 5 variations!

I'm thinking about getting an ESR Cap Tester, because I have a feeling I'll be dealing with bad caps yet again in the future.





.

- Pj
Awaiting delivery of CalMAN Kit. Vizio P-Series - 2014 P502ui-B1E (50") TV - Firmware: 1.1.19. Win7Pro & FireFox 38.0.5, Desktop Computer. ClearStream-4 Antenna, a dying DTX9950 Converter Box (See www.BadCaps.Net and Capacitor Plague), Philips 3576H DVR, Philips 19PFL3403D TV. My brother: Android-driven Sony 75X850C TV & now has M401i-A3.
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post #317 of 325 Old 04-28-2015, 03:43 AM
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I took out the Power Supply board and got the electrolytic cap stats from my DTX9950 (Cat 15-150, code 06C08):

Code:
       
All Caps are Rated 105 degrees Celsius: 

  C 1   22 uF  400v Micon KM+ 806   (KM, so is it Poor Quality?) 
  C 2   22 uF  400v Micon KM+ 806   (KM, so is it Poor Quality?) 
  C 4   22 uF   50v Micon KM+ 801   (KM, so is it Poor Quality?) 
  C 7  470 uF   10v Sam Young NXB 
  C 8  470 uF   10v CapXon KM C822  (Poor Brand) 
  C11  470 uF   16v CapXon KM C822  (Poor Brand) 
  C12  470 uF   10v Sam Young NXB 
  
I have 2 new caps from the R.S. cap pack I picked up years ago:

470 uF 25v I.S.L. (No temperature or other info.)

These ISLs are big, but I may be able to squeeze one or both on the board.

The height is quite tall, but I tested with the cover on and these 25v caps
will just fit with millimeter or two to spare.

I will try to install one or both of these 25v caps later today. Perhaps I'll
need to order some quality caps at BadCaps.Net. This guy only inventories
quality-made capacitors.

From what I gather on www.BadCaps.Net (in the Forums), these types/brands
are suspect that are on my Digital Stream DTX9950 PS:

Anything 'KM' as in 'CapXon KM'.

The CapXon brand.


So,
C8 and C11 would be suspect, eh? Perhaps one or both of the other
10v caps, too?


Could the large C1 and C2 be suspect?

Until I look it up, what is the best way to discharge C1 and C2 -
other than a direct short? An inline resistor? Value and wattage?


I think I can get this box working again - except for the intermittent
drop-to-zero signal that happens. Something on that coax input side
of the board must have a bad solder connection.

I have not found it yet when long ago I was inside there along with my
magnifiers.




.




- Pj
Awaiting delivery of CalMAN Kit. Vizio P-Series - 2014 P502ui-B1E (50") TV - Firmware: 1.1.19. Win7Pro & FireFox 38.0.5, Desktop Computer. ClearStream-4 Antenna, a dying DTX9950 Converter Box (See www.BadCaps.Net and Capacitor Plague), Philips 3576H DVR, Philips 19PFL3403D TV. My brother: Android-driven Sony 75X850C TV & now has M401i-A3.
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post #318 of 325 Old 04-28-2015, 08:34 AM
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That's funny in some ways, a site dedicated to bad caps. Cap-Gate.

I've suspected they substituted modified fish oil for the electrolyte. You know, China and all... I remember way back when Japanese motorcycles would come with fish oil for the front fork suspension fluid, funky smelling stuff when drained to replace with good stuff.

Could also discharge through a VOM in volt setting, analog model probably best. Should get most of it then finish off with a short or resistor.

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post #319 of 325 Old 04-28-2015, 09:32 AM
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I tried paralleling a 470uF 25v cap to all the 470uF caps one at a time and couldn't get it to work.

Brought out the heat gun to get it back up and running. I'll order some caps and see what gives then.




- Pj
Awaiting delivery of CalMAN Kit. Vizio P-Series - 2014 P502ui-B1E (50") TV - Firmware: 1.1.19. Win7Pro & FireFox 38.0.5, Desktop Computer. ClearStream-4 Antenna, a dying DTX9950 Converter Box (See www.BadCaps.Net and Capacitor Plague), Philips 3576H DVR, Philips 19PFL3403D TV. My brother: Android-driven Sony 75X850C TV & now has M401i-A3.
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post #320 of 325 Old 05-03-2015, 05:22 AM
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Quote:
Originally Posted by CleCakYngMfd View Post
I tried paralleling a 470uF 25v cap to all the 470uF caps one at a time and couldn't get it to work.

Brought out the heat gun to get it back up and running. I'll order some caps and see what gives then.



You have to remove the suspected caps. They don't just fail open but may have leakage. Sometimes actual real leakage of electrolyte onto the circuit board too.

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post #321 of 325 Old 05-03-2015, 06:19 PM
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Quote:
Originally Posted by zaphod7501 View Post

You have to remove the suspected caps.

They don't just fail open but may have leakage.

Sometimes actual real leakage of electrolyte onto the circuit board too.




Temporarily paralleling a cap to a suspect cap does not work? Invalid test method?

I think I just read online that electrolytic caps (at least some certain ones, if not generally) have about a 2-year shelf life? If so, the ones I have that have never been used before and are about a decade or more old, may be bad?

I'm going to order some caps, but I need to find out which 'series' I need. So many 'flavors' to choose from.



"actual real leakage of electrolyte"

None seen. I suspect one or more of these dried up, since this CB has usually been on 24/7 over the years.





.

- Pj
Awaiting delivery of CalMAN Kit. Vizio P-Series - 2014 P502ui-B1E (50") TV - Firmware: 1.1.19. Win7Pro & FireFox 38.0.5, Desktop Computer. ClearStream-4 Antenna, a dying DTX9950 Converter Box (See www.BadCaps.Net and Capacitor Plague), Philips 3576H DVR, Philips 19PFL3403D TV. My brother: Android-driven Sony 75X850C TV & now has M401i-A3.
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post #322 of 325 Old 05-04-2015, 07:08 AM
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If you check the specs on the caps, (usually at an industrial parts source) you'll see 2000 hours on duty life and shelf life. However, if you look close that is at rated temperature also. So, life is longer than the numbers would indicate but there is no good way to calculate actual life.

The reason for the limited life is the use of biodegradable electrolytes = organic, and organic degrades with time no matter what you do. The most common base seems to be fish oil, hence the moniker "Fish Caps" and the strong odor given off when they (literally) leak.

If the capacitor's ESR goes up (effectively a short circuit) then paralleling a good cap will have no effect..

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post #323 of 325 Old 05-04-2015, 09:27 AM
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The paralleling test would work if the cap is an open but not if a short. And if the value is off, which is probably common as they deteriorate, then the test would shift the net value to something that may not work properly in the circuit.

2-year shelf life sounds awfully low for a 'well-made' cap although I have read that electrolytics need to be energized every so often (I don't know the validity of this). It just seems a lot of shelved electronics would not work later on, but I've not experienced that or heard of it being widespread. Yet indeed the temperature-dependent decay (also high stress from certain circuits like those with high ripple).

High ESR would be like placing a resistor in series with the cap.

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post #324 of 325 Old 05-05-2015, 03:03 PM
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Quote:
Originally Posted by Floydage View Post
The paralleling test would work if the cap is an open but not if a short. And if the value is off, which is probably common as they deteriorate, then the test would shift the net value to something that may not work properly in the circuit.

2-year shelf life sounds awfully low for a 'well-made' cap although I have read that electrolytics need to be energized every so often (I don't know the validity of this). It just seems a lot of shelved electronics would not work later on, but I've not experienced that or heard of it being widespread. Yet indeed the temperature-dependent decay (also high stress from certain circuits like those with high ripple).

High ESR would be like placing a resistor in series with the cap.
I guess I should rotate my converter box collection.It makes sense,like not letting a car battery sit to long without a charge.
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post #325 of 325 Old 05-06-2015, 01:27 PM
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Quote:
Originally Posted by slowrench View Post
I guess I should rotate my converter box collection.It makes sense,like not letting a car battery sit to long without a charge.
Or just power 'em up for a few, less hassle.

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