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Equipment Repairs => PLASMA TV forum => Topic started by: BC109 on July 18, 2008,08:17:20

Title: LG 42PX5D
Post by: BC109 on July 18, 2008,08:17:20
This is the HD panel.
It has no picture or sound. LED goes from RED to Green then back to RED(Stby), thats it.
YSUS & ZSUS have been remove from power with same result. There is no main voltages Vs etc, even with green LED.
Would this be a power supply problem or can control PCB cause this?
Title: Re: LG 42PX5D
Post by: tv tony on July 18, 2008,08:35:23
monitor pin2 on plug 801 on the psu, when the relay kicks in should be approx 3.4 v. if this disappears when the set shuts down u have a control prob. usual cause is the two silver connectors on the two signal pcb's
do you want service manual?

regards tony walker
Title: Re: LG 42PX5D
Post by: norman on July 18, 2008,18:34:49
Hi, Sorry to hijack your thread, I need a Y sus board for my own tv, part number 6871QYH051P. Can you help Tony, a second hand board or even new one depending on price would be good. Thanks Norman
Title: Re: LG 42PX5D
Post by: BC109 on July 19, 2008,06:24:01
Thanks Tony.
I have a manual but it lacks in the power supply department. I seem to find Plasma manuals aren't complete & guess work is needed for the rest.

Norman, here in Australia they sell new for ~$270 AU + postage. Not to bad.
YSUS seems to be a common fault with these panels.



Title: Re: LG 42PX5D
Post by: tv tony on July 19, 2008,07:09:11
hello again norman, 6871qyh051p no longer available, replace with 6871qyh042, i dont know if this is suitable for you depends on control pcb fitted, get ready for price...£168.00, ouch!
Title: Re: LG 42PX5D
Post by: tv tony on July 19, 2008,07:27:31
Hello bc109,


 over the last few years we have compiled a list of stock problems for those sets, esp the psu, i will mail it to you, is yours the sanken psu or the sony, both were fitted in this chassis

regards tony walker
Title: Re: LG 42PX5D
Post by: BC109 on July 19, 2008,10:23:44
Thanks Tony,
I think it will be the Sanken I dont think I've seen a Sony PS, been wrong before though. I'll find out & let you know.

Last YSUS I replaced was about 3 months ago @ ~$270 (~132 pounds). But these things seem to be dynamic in price & availability. Didn't know you could substitute these boards

Thanks for your time.
Title: Re: LG 42PX5D
Post by: norman on July 19, 2008,17:25:16
Hi Tony, I usually get my spares from SEME. They list the 042 board as discontinued and replaced by 6871QYH051P. The price they quote me is an outrageous £215.10 + vat. I am hoping to get a used one from a damaged set. Thanks for the info. Norman
Title: Re: LG 42PX5D
Post by: BC109 on July 20, 2008,04:57:32
Hi Tony

Power supply board #3501V00220A.
All, Vs, Va, and even 3.3V remain at Ovolts.
RED LED is always on.
 
Pin 2 of P801 , Have 5V reading for a few second and then drop to zero, now red stand by light always on.  from there Pin 2 of P801 remain zero even if you try to turn on with remote or panel buttons.

Between two large signal boards, there is three silver connectors and how are they damaged or cause of fault?

Title: Re: LG 42PX5D
Post by: tv tony on July 21, 2008,04:08:26
right then, it sounds like a control fault, inject a 5v supply to pin 2, i usually just use the standby 5v, that must be present otherwise you wouldnt have led lit, the relay on the psu should latch on and stay on, you probably wont get much on screen if you have a signal fault, some dim illumination shoud be pesent though and you should now check for vs\va, the standby led will still go to red because that is fed from the micro, but all you are doing is forcing the psu int action, stay in touch, well sort it
tony walker
Title: Re: LG 42PX5D
Post by: BC109 on July 23, 2008,18:45:20
Ok, control board is ordered. The power supply is made by Sanken, is it possible to get that schematic, please.
Thanks for your help.
Title: Re: LG 42PX5D
Post by: tv tony on July 24, 2008,02:26:00
HANG ON, LET ME EXPLORE FURTHER
Title: Re: LG 42PX5D
Post by: BC109 on July 31, 2008,08:11:40
Control board fixed the problem, thanks Tony.
Any luck with that PS schematic, just out of interest?