Sorry - what's your exact model number here?

Model #


Sorry...both units are TCD648250B.

My hunch is that you have a failing power supply, which is pretty common on that model at this point.

See this info:

http://www.weaknees.com/bps

Bad Cap

Excellent thought. Thank you for the suggestion. I should have thought to look for that!

I did find a bad one! It was 2200mf 25v. I replaced it, no problem, (with an exact match) but the same symptoms are present (as per below).

All of the other caps look perfect. However, I understand that the root cause of my symptoms could still be a bad PS, despite the healthy appearance of the remaining caps.

To rectify the problem, I'm leaning towards sending the PS to you as an exchange unless you can suggest additional triage steps. For instance, do you typically find that any other specific caps are worth replacing?

Thank you again for point me at the PS.

Rico

Excellent thought. Thank you for the suggestion. I should have thought to look for that!

I did find a bad one! It was 2200mf 25v. I replaced it, no problem, (with an exact match) but the same symptoms are present (as per below).

All of the other caps look perfect. However, I understand that the root cause of my symptoms could still be a bad PS, despite the healthy appearance of the remaining caps.

To rectify the problem, I'm leaning towards sending the PS to you as an exchange unless you can suggest additional triage steps. For instance, do you typically find that any other specific caps are worth replacing?

Thank you again for pointing me at the PS.

Rico

We actually pro-actively replace most of the capacitors on the board - just because it doesn't show visible signs of failure doesn't mean it isn't failing.

But the exchange sounds like the right plan here.

the plot thickens...


So...I'm not ruling out the PS 100-percent, but I'm thinking that something else is wrong. My apology for the long-winded story, but here goes.

As I mentioned previously, two identical TCD648250B


--> One has gray screen (searching for signal) 100% of time, but otherwise appears ok (it boots fine, shows an up-to-date guide, it thinks it's recording, etc. but no ability to tune to any channels). All channels show "searching for signal" gray.

---> The second (identical) T3 works perfectly when connected to the very same cable-in coax.

Thinking that the caps were bad on the PS of the first unit, I replaced them...but it did not fix the issue when I reinstalled it into the first unit.

So, I swapped power supplies...putting the PS from the second unit into the first unit (the gray-screen "searching-for-signal" unit)...but that did not fix the issue either.

Then, I put the newly fixed PS (the one with the new caps) into the second unit...the one that worked fine to begin with, and lo and behold, it continued to work perfectly with the PS with the new caps.

So, neither PS appears to be the problem....as both worked fine in the second tivo. And neither PS fixed the "searching-for-signal" unit. I even completely reset (erased everything) from the "searching-for-signal" unit, and then reconfigured it, but to no avail.

Any further suggestions would be most appreciated. Unfortunately, the "searching-for-signal" unit is the one with the lifetime activation. Bummer!

Thanks

OK - that's a pretty definitive test, so it sure looks like you fixed the power supply properly.

Try an "overnight" test on the hard drive of the bad unit:

http://www.weaknees.com/54

Overnight test in-progress.

Here goes! Overnight test running. Trippy images!


I'll have a full report by morning...I hope.

Thanks again for your assistance.


bTW, this HDD was purchased from Weaknees a while ago.

Can you please share the specifications details for your Tuner?
What are the specifications for its coils and capacitors?
Share the circuit diagram if you can or the connections diagram atleast.

THe overnight test passed....but then...

So the overnight test passed, no issues...then...and this gets weird...

It still showed Searching for signal on all channels. I was about to toss it in the dumpster, despite the lifetime activation, but I tried one more thing...

I'd already completely reset the entire system (last week), and I'd already performed a full set-up routine (before the overnight test)...so I didn't have many more option left. Nonetheless, I did a Channel scan and wouldn't you know it? it worked!

I have no idea why (given that the unit was working fine a month ago) it would somehow need a channel scan performed to restore channels that it somehow lost. And what's especially curious is that it didn't get any viable channels until I ran the channel scan, despite the recent reset and full set-up routine.

HOWEVER, while watching the Oscars last night, at times the picture and audio were randomly distorted (highly pixelated video and choppy audio), but both were fine sometimes, too. To me, that seems like the hard drive is failing, even tho it passed the overnight test just last week. Would you agree with that diagnosis, or is the power supply (the one with the fresh caps -- but not ALL fresh caps) the likely cause of the video/audio distortion?

Thanks again for all your help.

It's a standard Series3 PS. That's all I can tell you. I don't have the schematic, and there are too many caps and coils to easily summarize.

If you replay a bad segment that was choppy from the Oscars, is the pixellation the same each time you replay the segment? If so, I'd vote power supply. If it's different every time, I'd guess the problem is with the drive.

.and the Oscar goes to Power Supply


Ordered!
Thanks again for your help.