What voltage should come out of the YER connector

[FrenchConnection67]

hi there, just trying to fault find my faulty plasma. I ve narrowed down my doubts on either the y sus or the z sus boards. I measure 194v out of the connector's pins labelled ZER on the y sus board, supplying my z-sus board. Is this value ok to youz, expert?

also I ve taken out my z sus board and get a perfect continuity between the ZER connector's pins and ground which looks like a short circuit to me. I also get contuinity between ground and all the z sus out pins of the IC.

therefore I suspect a short circuit on that board, most probably on the IC but before I go and buy a replacement board or just a new IC, I d like some opinions of youz, experts.

ta

[tom66]

Re: What voltage should come out of the YER connector

The voltage should be approx 1/2 of Vs. So yours is too high.

[FrenchConnection67]

Re: What voltage should come out of the YER connector

ok thanks tm66


and what about the continuity between the ZER and gnd?

[tom66]

Re: What voltage should come out of the YER connector

Should be open circuit or reverse biased diode (600mV)

[FrenchConnection67]

Re: What voltage should come out of the YER connector

ok therefore my z sus is definitely in short circuit. now, you also said that I get a too high voltage out of the YER connector, does this mean that my y sus is faulty as well because if it is the case I could forget to repair this tv, not worth it. that would be a bad news

[tom66]

Re: What voltage should come out of the YER connector

It is not out of the question that the Y-sus has damaged the Z-sus. I don't think an old LG like this is worth fixing much, picture quality is poor and they have sparklies issues on many models.

[FrenchConnection67]

Re: What voltage should come out of the YER connector

I see where you re coming from but I really wanted to keep it and try to repair it.

what does yer and zer stand for by the way tom?

[FrenchConnection67]

Re: What voltage should come out of the YER connector

can you give me more info on what this yer output is really for? much appreciate

[tom66]

Re: What voltage should come out of the YER connector

Combined energy recovery. The Z-sus and Y-sus discharge the plasma panel on each sustain cycle. They work in an alternate pair. Y-sus discharges through Z-sus to sustain Z-sus side, and vice versa. Reduces power consumption of the TV in operation, makes the panel last longer. That massive inductor component marked 5R6 on your Z-sus is part of this circuit, to help resonantly recover energy.

[FrenchConnection67]

Re: What voltage should come out of the YER connector

ok thanks for the explanation. you know, when I measured my voltage 198v out of the YERs the connector between the y sus and z sus wasn't connected.

that is perhaps why I got a so high volatage???? are you really sure it should be half of that. or does it not half when boards are all connected together and screen lights up, sucking some of the voltage.

by the way, I don't try to challenge but only understand. I am really tempted to buy a z sus board and try you know. it only cost 30 pounds, that s why I am digging.

hope you understand

[tom66]

Re: What voltage should come out of the YER connector

You might be right on that. Not sure myself.