Re: LG 50PV400 not turning on/relay clicking



Thanks for the reply... I have it working again for the moment, but I will try this next time I have a problem (don't want to risk messing it up for now).

What I did over the weekend was actually disconnect AUTO GND from the main board so that the SMPS comes fully on without needing RL_ON and M_ON from the main board. When I applied power, the panel came on as expected, but the standby light was still on (since the mainboard wasn't booted). However, in this state I was able to then power up the main board...

Re: LG 50PV400 not turning on/relay clicking



According to the manual, the main board should be sending the M_ON signal to the SMPS, which turns on Vs and Va, but this never happens. The main board sends R_ON which turns on the relay, all the voltages come up (except Vs and Va), and then instead of activating M_ON, the main board deactivates R_ON, the relay shuts off and the SMPS goes back to standby. Except when it finally works and I'm using the power bar to turn it on and off - then it works properly every time.

This is the behaviour I'd expect to...

Re: LG 50PV400 not turning on/relay clicking

It's possible, although the behaviour isn't totally random... I used it everyday for the month and a half by using a power bar to turn it on and off and it consistently worked every single time. But now that it got shut off "properly" it won't work. This happened before too, I was using it for weeks with the power bar trick, then it got shut off properly and wouldn't work. I don't know what caused it to start working again - over a couple of weeks I tried to get it to come on and one day it just finally did.

I feel...

Re: LG 50PV400 not turning on/relay clicking

Thanks for your reply.

I suppose the IR board is possible. I don't think I've actually tried applying power with that board disconnected from the main board so I can see what happens in that case. Normally if the TV is going to work, it powers on as soon as it's plugged in, so I'll see what happens without the IR board connected at all.

I'm not sure how that would relate to what seems to be consistent behaviour once it does come on and I shut it off by killing the power... but at this point, I'm out of ideas...

Hi everyone,

I've been having trouble with my 50PV400 for some time now. While plugged in, the standby light is on, but turning it on (using either the remote or soft power button on the TV) causes the relay to click on, then click back off after about 1 second.

This seems to be a very common problem, and I've tried everything short of replacing boards (yet). I have the training manual for the 50PV450 (thanks tom66 for your manual database) which is basically the same TV. I've measured all voltages from the SMPS, powered the SMPS up in stages as described in the manual,...

Re: New Members - please post your introductions here

Hello,

My name is Christian, and I'm from Canada. Electronics have always been a hobby of mine, although these days my job as a computer programmer/systems administrator and real life have meant less time for that kind of thing.

I'm here because I've exhausted my own skills, as well as all the information I can find online, about the problem I'm having with my plasma TV. I'm hoping someone here will have some information I haven't already come across.

I've been a lurker here for quite...