50PC1D Help Psu Shutting Down ?

[ReeceyBurger123]

Just need some suggestions before I crack the sope out on this old fucker. 2006 Lg Hd Plasma, originally had failed 46N15 transistors on the buffer and a shorted IPM (ERC track shorted) on the Ysus as well as the Psu having about 13 bad Samwha WL caps, however the Tv did switch on just gave a flashing image due to failed Ysus etc.

I repaired the Ysus and buffer, as well as recapping the Psu fully apart from primary's. Now Im greeted with a clicking Psu with or with out Ysus/Zsus connected.

Vs charges then shuts down followed by a click from the relays. Everything is soldered properly and the repaired boards dont not have any shorts. The AC Detect and RL-ON/VS-ON are perfect until shutdown and all voltages are present.

Any suggestions going to put this aside for a few days before I smash it up lol I know the power supplies are known to have issues but these 50PC1D's are a bloody nightmare riddled with faults. Let me know cheers chaps

[Alastair E]

Re: 50PC1D Help Psu Shutting Down ?

I got two of these Behemoths in the W/S at the mo....

Dunno just what to do with 'em. One Ive rebuilt an IPM with DG502's and it runs fine, The other Ive had for months but haven't looked at yet, for fear of breaking my back!

I do know, the AC Detect has issues--but never had them myself. Apparently, even the Great Tom hasn't figured that one out--but Fecked it to work by shorting two opto's...

Usually just IPM's and PSU Caps, maybe the odd Mainboard fault is all that happens--The 50's are usually free of the Mal-Discharge the 42" has, and have a reasonable picture.....

Quite a good set--They ARE now 10 odd years old, usually up at 25,000 odd hours, not bad really, There's many other sets much younger and totally stuffed...
Also, Ive Never seen a dead COF Chip on any PC1D/A set, maybe due to that Massive heatsink all along the bottom!

[ReeceyBurger123]

Re: 50PC1D Help Psu Shutting Down ?

Cheers Ali, they are good build quality I like the fan design too works well and yes the panels are very reliable in these due to the huge heatsink if only they all used heatsinks like that on the address buffers Plasmas could live forever. Also yeah my Ac detect stays at 5v so Ive no idea what is shutting it down.

I might repair the orginal Ipm and stick that back on rule that out but Im quote sure this is a Psu failure on this one, just takes alot of time to diagnoses it and Ive not got the effort for this as it only will sell for £180. I do get all sus voltages Ie VSC, Vy etc but nothing obvious is causing it to shutdown. Got any ideas let me know

[Alastair E]

Re: 50PC1D Help Psu Shutting Down ?

Bugger me! £180 for a 50PC1DA!

I would be lucky to get £130! I sold a Panasonic 50X20 for £150 just last week.....

[ReeceyBurger123]

Re: 50PC1D Help Psu Shutting Down ?

Yeah sales quite good round my area

[Andrew F. Ali]

Re: 50PC1D Help Psu Shutting Down ?

yeah sales quite good round my area

+1

[ReeceyBurger123]

Re: 50PC1D Help Psu Shutting Down ?

Still not got around to this, ahhh I need to diagnose the bastard no motivation though

[tom66]

Re: 50PC1D Help Psu Shutting Down ?

I'd check and see if the low voltage rails (15V, 5V?) shut down before the Vs/Va.
You can use a scope to do this.
That will give you a clue, the other rails won't run if the sub rails shut down (protection, and also the Va circuit loses drive power)

[ReeceyBurger123]

Re: 50PC1D Help Psu Shutting Down ?

Cheers Tom, its just effort I want to sort this as put alot into it. But Ive got loads of others to get on with will have a play probably tomorrow.

[flocko]

Re: 50PC1D Help Psu Shutting Down ?

I can recall repairing a set of this model a few years back, that when trying to improve an image problem, adjusting Vs+Va the power board would go into shutdown if you dropped the voltages to low,turning the trimmers (voltages)back up would restore it after a restart with the remote. try running with unplugged Y+X see what voltages the power board is putting out

[Alastair E]

Re: 50PC1D Help Psu Shutting Down ?

Yes--Now you come to mention it, I remember messing round altering Va and Vs it shutting down.
It would go off with a huge Bump through the speakers! Rather alarming--sounds like its destroyed summit, but its just the PSU cutting everything--all at the same time.

[ReeceyBurger123]

Re: 50PC1D Help Psu Shutting Down ?

Hmm interesting I cant remember playing with Vs Va, however the panel does sort of half prime then it shuts down. Will have a play tomorrow, I did the same on a 50PG3000 but after a hard reset the set worked even with the pot in the last position.

[flocko]

Re: 50PC1D Help Psu Shutting Down ?

Yes Alastiar the same bump though the speakers you got if you tried Toms AC detect power board fix ,shorting the opto, very alarming and sounds like an expensive blow up

[tom66]

Re: 50PC1D Help Psu Shutting Down ?

Yep, only happens because power board loses power then half a second later goes "wait...my bulk capacitors are empty...SHUT IT DOWN BOYS!"

If you have working AC detect, the main board realises before it's too late and cuts the power to the audio and plasma panel.

I would second checking Vs/Va, I believe it's actually if Vs or Va are overvoltage that it will trip, can happen if the pots are tuned too high.

[ReeceyBurger123]

Re: 50PC1D Help Psu Shutting Down ?

Hmm well its not Vs or Va, with Ysus connected Vsus is way too low only 120v before shutdown with Ysus/Zsus out its 195 before shutdown which is what the panel spec is also lower drive voltages are fine. The control board Leds seem to change pattern some times as well but my sus voltages are mostly correct.

Just got to sort another 50PS3000 atm but will get back to this later.

[Alastair E]

Re: 50PC1D Help Psu Shutting Down ?

They do trip at Under-Volts too...

Both too high and too low will give shut-down with bump...
--I remember that when playing with the Va and the Vs on one of these...

[Alastair E]

Re: 50PC1D Help Psu Shutting Down ?

Whats up with your 50PS3000, --Ive got one that most of time wont start up. When it does--it runs fine...

[ReeceyBurger123]

Re: 50PC1D Help Psu Shutting Down ?

The PS3000 is a bastard lol, shorted SMP driver Ic on the Ysus covered in glue near the transformer nearest the Tcon. Replaced that, short from 5v line on Ysus went set worked

Hours later Zsus failed Vzbias circuit up in flames, 3 fets short and resistors blown. Got that on order now. Fancy selling me yours ? Before I smash this one up lol because now the short on the Ysus is back after the Zsus blew.

Also Ali on yours I would say it has a Bga solder issue. These PS3000's are shit Tv's riddled with faults with all boards and the panels !

[ReeceyBurger123]

Re: 50PC1D Help Psu Shutting Down ?

Also on the PC1D hooked up a light bulb as a load in series with Vs, psu still shutting off. Pfc bus is working so I suspect something on the feedback is gone but struggling for time atm. Bloody Lg fucking shit Tv's hate these more than VESfuckingTEL !

[Alastair E]

Re: 50PC1D Help Psu Shutting Down ?

I can tell you--the 50PS VZ-Bias issue is ALL the tiny caps on the Control-Board!

--Dunno the failure-mode, but replacement stops the reg and the mosfets in the VZ-Bias on bottom heatsink from heating and shorting, and taking out that WW series-resistor...