DigitalStream DTX9950 - Page 11

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.
Edited by holl_ands - 10/23/12 at 8:27am

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

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?

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).

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.

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.

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

 

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

 

[2] Yep.  20. 

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.

 

 

 

 

 

 

.

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.

 

 

[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.

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!