Lg 42pc1d

[smallprint]

I have an LG 42" plasma that i've had for a while now and i've had to replace the YSUS board in the set and the replacement has only lasted a couple of months before it went pop again. Any suggestions on what could be making this part so susceptible ? prior to it going pop there was a build up of a red pixel like haze which got worse and worse before the inevitable happened. Any relevant info greatly appreciated many thanks.

[Alastair E]

Re: Lg 42pc1d

Just Old Age kills the IPM's....

You can try replacing all the electrolytics around the DC/DC Converter on Y-SUS,that can/could cause early demise, but you are still stuck with a finite life of S/H IPM's, (New are not, and never were available separate from the board) Adding fans to 'em may extend their life though, as they do run very hot....

You can in some cases, repair the IPM's by removing the dead 'die' component IGBTs and replacing with a conventional package device--Providing the Driver circuits in the IPM survived.....
You'll need to use 330V 300A (Ip) devices for replacements, such as the FGPF4633 IGBT.

The red-spots issue has little to do with the IPM failure and more to do with panel aging needing a Firmware-update to control-board to compensate for.
--Give us a PM if you need your control-board updated--It requires a special jig and software to update it that I have.

[mmartell]

Re: Lg 42pc1d

Hey Alastair I have a Toshiba 50" PC1DR clone which has serious red pixelling but only in the upper two corners and down the sides somewhat. I can't imagine the set "aged" in this fashion. Do you think a control board firmware update would fix this or what would cause this type of failure ?

[Alastair E]

Re: Lg 42pc1d

It may Help--but basically, your panel is well worn, if you have Mal-Discharge (Red-Spot) at sides/top. How many hours on it?

If over 20K hours, I would say the panel is well worn.

Ive got one much the same, At sides and top, mal-discharge, middle fine, the update Improved--but did not cure the problem, you can adjust SET_Up/SET_Dn (X3 panel, not fitted on V8, 480 EDTV panel, only the 720p) which will either give red-spots--Or bloody cruddy low-light grainyness--pixel misfiring in same picture areas....
I scrapped the set due to this, which was a shame--it was immaculate otherwise.

This panel has 26,600 hours...

The panel was probably made with very slight differences in thickness of the di-electric layer between centre/sides causing the wear to show at the sides first...

--The Di-Electric Layer of MgO is subject to wear and erosion by the plasma gas discharge over time, according to various sources Ive read, making it thinner...

[mmartell]

Re: Lg 42pc1d

Interesting. Ok, noob question.. how do I check panel hours ?

[Alastair E]

Re: Lg 42pc1d

(For LG sets) Press and hold Menu on Remote and the set for more than 5 seconds....

[mmartell]

Re: Lg 42pc1d

Can't get that to work. There is no discreet Menu button, it is accessed by pushing ch up/ch dn at same time on set. There is a discreet Input button but using those two does nothing.

[mmartell]

Re: Lg 42pc1d

Shoot I should have been more clear - this is a Toshiba 50HP66 with LG innards, it's quite possible there is a different access combination if any at all. Will google it..

[mmartell]

Re: Lg 42pc1d

Ok info was in the Service Manual.

PDP ON = 5D93 or 0x5D93 = 23955 or 24k hours.

Sounds like you are correct, uneven panel aging due to manufacturing process. Thanks for your input.

[ajshoe]

Re: Lg 42pc1d

Have a set that I repaired last year (replaced IPMS) and got it back last week. IPMS failed again. Has 29,500 hours on it. put in new IPMS - it buzzes very loudly. Scrapped it. Tried replacing all the boards - didn't change buzz. Weird part was pic was fairly decent - no red blurr on edges. These sets are built compared to the new crap out today. Bit have parts for the next one !