Rca lcd hdmi only

[VINTAGE.FAN]

A few years ago I was given a Rca 32" lcd that had been hit by a power surge, possiblg lightning. The set powers on, has all menu funcionality, and still shows a great picture, but through HDMI only. All the analoge inputs including the tuner, display "no signal" on the screen. The main board and power supply both look great, no burns or bad caps. Does anyone have any ideas, aside from a new main board, that could get this thing going again?

[N2IXK]

You would need a schematic to even BEGIN to troubleshoot this issue.

The issue sounds like it is either in the input switching circuitry, or the interface between it and the main microcontroller. You would need to look at the signals from the microcontroller which select the various input sources and see if they are actually toggling high and low as required.

Once you figure out where the problem is, you will then need to replace the failed component. It could be a simple failed diode or transistor holding a control line high or low, or it may very well be part of a custom ASIC in a huge pin count PLCC package, that will require really good soldering skills to replace (if RCA will even sell you one). And if you are dealing with something like a BGA package, you are pretty much screwed as far as replacing it without specialized, expensive rework equipment.

Issues like these are why component level repair of this stuff is rarely done, and entire modules are swapped or the whole unit is tossed and replaced with a newer model.

[VINTAGE.FAN]

Yeah about all that. Being as its 6 years old and used as a spare tv now, and it was a walmart sold set made by TCT electronics or some crap, I'm thinking ill let this one be. I dont have any way of even starting to get a schematic, much less any test equipment other than a multimeter! Thanks for the reply though, always good advice here.

[ischmidt]

You can get standalone ATSC tuners with HDMI out if that's what you're looking to do. I don't know of any solution for getting composite/s-video into it though.

[Geoff Bourquin]

I remember something about a fuse on the main signal board going open on some RCA LCD sets about that age. Some things, like the tuner quit but the set still runs. I think audio would distort or disappear. I dont remember if HDMI is one of the things that still works or not. It is a tiny surface mount fuse, so get your magnafying glass out. I think it was near (an inch or two) the top left corner of the mainboard. RCA suggested leaving the open fuse in place and tacking a new one on top of it. I dont remember the size but can look it up if you need it. I think it was 3.5 or 4 amps, something like that

[VINTAGE.FAN]

That would be worth checking, and totally awesome if it were to cure the problem! The thing has no audio, but has been used as a bedroom monitor with directv and surround sound until recently so none of these issues mattered. I'll check into it and post my findings!

[Geoff Bourquin]

I checked my notes, the fuse is labeled 1C33 on the board. Starting to wonder if it may have been 1 amp or something like that. When I don't know the right size, I usually measure what flows there, then double that for the size of fuse. I'll look it up when I have my service data at hand.

[VINTAGE.FAN]

Upon further inspection, several small "resistors" if you will, near the analog inputs, are fried, and burnt. I guess a new board will be required to get this one running again. Heres a pic for reference, sorry its so blurry.

[N2IXK]

If enough energy went through to cause visible damage like that, there are almost certainly other components which have internal damage, as well.

Just about anything can be fixed in theory, but in practical terms, you are looking at replacing the entire board when something like that happens....

[Geoff Bourquin]

Ouch! Kinda looks like the board is toast. I agree with N2IXK, it CAN be fixed, but what's the point when it'll cost as much as a whole new set. Sorry, I thought we were on to something for a while.

[VINTAGE.FAN]

Yeah, not buying anything new or otherwise! We got a new one for the bedroom and this is in the garage now, I'll keep it for parts, maybe ill come across one needing a screen or something!

[Jeffhs]

Originally Posted by ischmidt

You can get standalone ATSC tuners with HDMI out if that's what you're looking to do.

That's what I was thinking. If you still want to use the TV, and the HDMI inputs still work, you can use an outboard ATSC tuner or even a cable box with HDMI outputs. This seems to be how TV is going anyway -- away from RF-based signal input to direct video input to the set. A tuner or cable box connected to your set with an HDMI cable will give you a better picture as well, since HDMI is a far superior connection to composite or S-video. If your TV has more than one HDMI input (most sets have at least two), you can use your ATSC tuner and a Blu-ray or DVD player as you did before the TV's own tuner was damaged. If the audio section of the set was damaged as well, you can (as you did anyway) run the TV's audio output through a surround-sound system; the best part is you will have much better sound with this setup than the TV's own audio stages could ever deliver through the puny speakers found in today's HDTVs, since you will be bypassing the set's internal audio system altogether. The only thing you will be sacrificing is the "mute" function on the TV remote, as the audio output jacks on most HDTVs are not muted when the mute button is pressed. If you get a home-theater remote such as Logitech's "Harmony" series, et al., you may be able to program it (through its online programming feature) to mute your home-theater sound system's audio.

[jr_tech]

Something like this might be useful:

http://www.amazon.com/Mini-Composite...hdmi+convertor

not affiliated,
jr