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Discussion Starter · #1 ·
I have been recording HBO and SHO using the pany combo for about two years now without any problems. For a week now, I have been having video and audio breakups on the HD channels on my dish 5000. They randomly come and go, at times just a minor breakup at other times it is so constant that it is unwatchable. My dish pointing signal strength is around 90. The SD channels seem to be ok. Is anyone else seeing this??? Since no other threads have asked this question, I assume it is in my equipment. Has anyone had a failure like this? Any ideas on what to check? I just hope it isn't the modulator!
 

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Yes, several times. And it is probably not the dish 5000 but the panny tuner that develops this problem. I have had to replace several of my tuners. You should call panasonic service.


bb
 

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Alternatively you might try joining Forum member gridleak's war on pixels, breakups, and dropouts .


Roger describes in careful detail how to open up the Panasonic STB and then remove and reseat many of the internal connections that might affect the digital signal.


In some cases this is enough to eliminate the sorts of problems you describe.
 

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I tried Roger's TU-DST50 unseating/reseating techniques with excellent results for a month or two, but the dropout issues eventually returned. I then sent the unit back to Panasonic and they did some soldering and unspecified other modifications. I've not seen a single pixel/dropout issue since I got the unit back. I think the total repair cost including return shipping was $230.
 

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Yes, there's another common source of pixels in the DST50/51. I talked a little about it here , but I don't think I ever posted any details.


The fix involves removing the tuner CBA, bending one of the shields slightly, re-soldering the pins that connect the tuner to the circuit board, and then re-installing the tuner CBA in a manner that produces no mechanical stresses. There are also some adjustable resistors on the CBA that can be "worked" and then returned to their original setpoint. I did all this last December to the one remaining DST51 that was producing pixels, and it's been pixel free ever since.


I think you can see why I never posted about it: it gets a little messy. However, it's easy to see why it works. Just take the lid off your DST50/51 and tap lightly on the ATSC tuner while you're watching the output. You'll see pixels all over the place. The tuner is full of little air-core inductors. A light tap will make them vibrate enough to screw up the bit stream. The tuner runs very hot, and the heat combined with mechanical stress can result in mechanical "clicking", much like the noise you hear when the forced air furnace in you home fires up. That "clicking" is what makes the pixels.
 

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Joby, before we all go nuts here rebuilding your system, we need to know if the problem is in the modulator or the STB. There are some ways to determine that, but I need to know what STB you have and whether you can receive OTA.
 

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I was having the same problem a month ago. my OTA reception and recording were rock solid but I was having a significant number of dropouts from the HD modulator. ruined my tape of Caddy Shack and it was only on once last month.... Anyway I had been using Ken H's settup for tieing in both ota and the modulator but without adding the line amplifier for the modulator signal. I think that is what was causing my problem. I added the Amp and for two weeks I have not had a single drop out.



see this thread

http://www.avsforum.com/avs-vb/showt...ighlight=wezar



Good Luck
 

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Discussion Starter · #8 ·
Wow! Thanks for all the advice. Wezar's comment about a line amplifier, coupled with the fact that I get rock solid OTA reception of San antonio and Austin stations (which are 90 miles away) led me to belive that the modulator's RF output which has always been weak, has gotton weaker. I have a few 10 DB line amplifiers in my junk box, so I put one on the output side of the modulator. So far no pixles!


Now this brings up another question. For two years I have left the 5000 on constantly. If the RF amp transistors are getting weak, would it be better to continue to leave it on, or turn it on and off subjecting the silicon to the voltage bounce of powering up and down?????
 
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