LG 32LC7D no sound

[tom66]

Re: LG 32LC7D no sound

Yeah, it's probably the rightmost IC on that image.

[CR Designs]

Re: LG 32LC7D no sound

Sorry can't read the IC's but have squared 5 out for you to check for Tom66's suggestion. RU3037

Thank you for reply. It is the upper right mostfet

[CR Designs]

Re: LG 32LC7D no sound

Yeah, it's probably the rightmost IC on that image.

That's it , here's the reading off it.

1&8=.919
1&7=.924
1&6=1.083
1&5=1.068
can you tell me what to buy at digikey. I'm not sure what to buy,Thanks

[tom66]

Re: LG 32LC7D no sound

What is part # on it? Looks like only one chip so only need to replace that.

[CR Designs]

Re: LG 32LC7D no sound

What is part # on it? Looks like only one chip so only need to replace that.

Part #u3037m

[tom66]

Re: LG 32LC7D no sound

OK, then this should do:
http://www.ebay.co.uk/itm/IR-IRU3037...item53f505b5ac

May want to get second one as it can be difficult to solder.

One pin to check: pin 1 to pin 4, DC20V scale. If IRU3037 is working well, it should be around 1.25V +/-5%. If not, it will be lower or higher.

[CR Designs]

Re: LG 32LC7D no sound

OK, then this should do:
http://www.ebay.co.uk/itm/IR-IRU3037...item53f505b5ac

May want to get second one as it can be difficult to solder.

One pin to check: pin 1 to pin 4, DC20V scale. If IRU3037 is working well, it should be around 1.25V +/-5%. If not, it will be lower or higher.

Not sure about how to check the 1 to 4 pin with the board off the tv ?

[tom66]

Re: LG 32LC7D no sound

It needs to be checked with board installed & TV running with fault. You may have to solder wires to pins, install board & measure that way.

[tom66]

Re: LG 32LC7D no sound

Just a note if doing that you only need to check pin 1 to ground (which is pin 4).

[CR Designs]

Re: LG 32LC7D no sound

Just a note if doing that you only need to check pin 1 to ground (which is pin 4).

Thanks tom66 will check it and post reading

[CR Designs]

Re: LG 32LC7D no sound

Thanks tom66 will check it and post reading

Tom66 It read 1.24, so do I need to replace it ?

[tom66]

Re: LG 32LC7D no sound

Hmm, I would replace it anyway, but that is unexpected. Someone else on this forum had that chip fail with same fault but different power supply. I wouldn't be as certain as I was before, though. If it doesn't work, it may be one of the feedback resistors is bad. If the input-bias of the IRU has increased, then it could still cause this...

[CR Designs]

Re: LG 32LC7D no sound

Hmm, I would replace it anyway, but that is unexpected. Someone else on this forum had that chip fail with same fault but different power supply. I wouldn't be as certain as I was before, though. If it doesn't work, it may be one of the feedback resistors is bad. If the input-bias of the IRU has increased, then it could still cause this...

I will order the part, will post when I get part and have it installed. Thank you for your help

[sayanything]

Re: LG 32LC7D no sound

Having same problem. Changed all capacitors now no sound.

[jstiene]

Re: LG 32LC7D no sound

Hi Tom,
quick question. so I hav a 32LC7D-UB that didnt power up so I replaced the PSU caps and it turns on now and picture is distorted from cable connecton but HDMI is perfect. Is there a reset I need to do or is this is problem with the main board? I did do a cable scan also. the audio is fine, the picture just looks is if there is no antenna/cable connected securely. Have you seen this before? Hopefully it is a easy fix?
Thanks!
Joe

[tom66]

Re: LG 32LC7D no sound

Check if the 3.4V output on power board is OK.

[jstiene]

Re: LG 32LC7D no sound

Thanks for the quick reply. So I measured the 3.4v on all 3 connectors. 2 of the 3 connectors were at 3.4V and the 3rd connector (P201) measured 2.38Volts. Also, I realized there are 3 caps that I did not replace that were not in the kit for some reason that I bought (2200V-25, 2200uf-10v and 1500uf-35v). these were not swollen but maybe my problem?

Also, I assume HDMI runs good as it is using lower voltage?

Check if the 3.4V output on power board is OK.

[tom66]

Re: LG 32LC7D no sound

Can you show which connectors have 3.4V on them? The 3.4V failing causes a variety of issues: DVB failure (no digital TV or blocky image), HDMI failure, remote control fault, side button fault, audio faults and failing to power on.

[jstiene]

Re: LG 32LC7D no sound

Here is the image. The 2.38 volts is found on the connector closest to the edge of the motherboard - connector P201.

[tom66]

Re: LG 32LC7D no sound

That's fine -- it's simply an on/off signal (3.4V ON) which >2V is OK. So you would most likely have a main board problem. I note this TV uses a different PSU to others. Can you post a picture of the main board? This is the board with the HDMI inputs on it... there may also be a 2nd main board with other inputs on it.