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View Full Version : No A/V in after socketing patched prom



spaceranger
01-25-2005, 11:17 PM
With trepidation today I desoldered the prom on my tcd540040 and installed a socket and patched prom (from compwiz). It did not boot. I found a solder bridge with my ohmmeter (it was under the socket where I could not see it) and fixed it with some solderwick. There were readings like 4.7k and 10k between some of the pins, but I figure that's normal. Re-inserted prom and it booted fine.

All my recordings seemed to be intact and I played one to be sure. It played.
Then I switched to live video and the screen was black and no audio. I plugged the source (sat) directly into the tv and it was fine. The tivo detected it when I unplugged the video, showing the usual screen.
When I plugged the source back in that screen went away as it would normally. Still no A/V visible from source.

Also something else is weird: I went into phone and network setup and everything looked normal except it said:
Last success Tues Jan 25 1:27AM
Last attempt Tues Jan 25 1:27 AM
Next attempt Tues Dec31 9:52 PM ?????????????????????????

So I decided to force a call(wireless)
It went through the process and while it was processing data I went
back to phone and network settings and it said:
Last success Tues Jan 25 1:27 AM
Last attempt Tues Dec 31 9:55 PM
Next attempt Tues Dec 31 9:52 PM

Now that the data is processed it says:
Last success Tue Dec 31, 9:55 PM
Last attempt Tue Dec 31, 9:55 PM
Next attempt Thu Jan 27, 12:25 AM

Did it step through a time warp or did I overheat the battery or short it out with the aluminum foil heat shield?

Why no A/V? Could it be the prom? Bad connection at prom?

alldeadhomiez
01-25-2005, 11:42 PM
Your original PROM will run a SHA check on itself, which should detect pretty much any bad connection(s) of consequence.

It's entirely possible that something else got messed up, but IIRC the PROM isn't very close to the video inputs or encoder so I'm not sure what it could have been. The battery/clock stuff should not have an effect on it.

spaceranger
01-25-2005, 11:48 PM
Your original PROM will run a SHA check on itself, which should detect pretty much any bad connection(s) of consequence.

It's entirely possible that something else got messed up, but IIRC the PROM isn't very close to the video inputs or encoder so I'm not sure what it could have been. The battery/clock stuff should not have an effect on it.

Are you saying to try the original prom (which I heated to 800 deg.) as
the one I'm using is patched (presumably with the bin you posted)?

spaceranger
01-26-2005, 11:46 AM
I inserted the original chip and watched the boot in teraterm.
It showed the following gobbledygook: MC@x@B-2|8n
Actually the C had a little hook on the bottom and the 2 was up at the
top of the line, like the squared symbol. It did not boot. My conclusion is
that the prom was cooked in removal or not seated well in socket.

I then put in the patched prom and watched in teraterm while booting.
No output to teraterm screen whatsoever, but it booted fine and now
has A/V in working OK. Maybe it was a little bit of flux...

At any rate, thanks for the info, ADH! It did get me going.

Sorry for the panic post: I was a little freaked. It's been a long time since I lost a patient in surgery and I'm relieved to have brought him back to life!
It's been over 5 years since my last smd surgery and my eyes ain't what they used to be...

Thanks again!