Lg 50ps3000 with flashing standby light

[squirestubbs]

Hi, im a newbie, from the UK, Iv'e got a LG50 PS3000-ZB plasma that when it is turned on, the standby light just flashes, then stops, then starts flashing again. Tv is 15 months old. Had a Tv engineer look at it, and he wants £300.00 to fix it. He said it was the main board that was at fault, I have replaced this board, but problem still there. Read different forums regarding this problem, and they range from ;bad caps, bad power supply, bad boards etc. Done different tests by disconnecting boards, and found, that when the zsus board is not connected the tv fires up, grainy menu screen, and the remote operates normally, all voltages are ok. Is it just a case of swapping the board, or could it be repaired, is it likely to be something else. Thanks for any help.

[Pyr0Beast]

Re: Lg 50ps3000 with flashing standby light

Bad PSU that dies with usual load but works with lowered.

[squirestubbs]

Re: Lg 50ps3000 with flashing standby light

Thanks for quick reply, new board or is it repairable.

[Pyr0Beast]

Re: Lg 50ps3000 with flashing standby light

No idea. Needs more testing to show where the fault is.

[PowerAmpFreak]

Re: Lg 50ps3000 with flashing standby light

The flashing led sequence may actually give you a fault code. Count the amount of flashes and try to find the service manual for the set at Elektrotanya.com. If you're lucky, the led sequence shows a defective Z-SUS and you may want to replace that board.
Anyway, most service manuals provide their troubleshooting help like you already did - Disconnect one board at a time, power up the set. That board which refuse the set to power up normally is having a failure.
Most Z-SUS and Y-SUS are possible to repair, but sometimes it might be worth to just replace the entire board.

[squirestubbs]

Re: Lg 50ps3000 with flashing standby light

Thanks for the reply Power Amp, I have read different forums, mainly in the US about the Zsus board becoming more of a fault now, on LG plasma's. Flicked through a service manual for the ZA chassis, don't know if its same as the ZB, but they don't mention any thing about a flash fault code, have seen flash fault code for samsung somewhere on the net. I will search some more, and try to find a board........ thanks

[Wizard]

Re: Lg 50ps3000 with flashing standby light

This is much newer design. Check fuses, then inspect the buffer ICs that runs vertically on left, those square black ICs for any cratered hole (blown out). If not, ohm measurment is needed.

Even newer plasma TV design have no fuses on the ZSUS and YSUS boards, and a well designed SMPS that detects overload and shuts down.

Cheers, Wizard

[Time2spare0]

Re: Lg 50ps3000 with flashing standby light

hi i have same problem, decided to replace the zsus board but having problems finding one, can anyone give me a good site to buy one from please, thanks for any help in advance

[f67bird]

Re: Lg 50ps3000 with flashing standby light

hi i have same problem, decided to replace the zsus board but having problems finding one, can anyone give me a good site to buy one from please, thanks for any help in advance

If you live in the US, eBay can be good for finding cheap working used boards if you don't mind sometimes waiting or digging.
Encompass will sell you a new or "green" one also.

[Time2spare0]

Re: Lg 50ps3000 with flashing standby light

If you live in the US, eBay can be good for finding cheap working used boards if you don't mind sometimes waiting or digging.
Encompass will sell you a new or "green" one also.

thanks for the answer, but i live in the uk, seen the boards on the us ebay but not sure if they will work in a uk tv (voltaged differance not sure) found a few sites in the uk but they all out of stock and when i contact them they are also having problems getting hold of the boards..lol looks like i may have to give up on my lovely 50 inch lg tv,, what a bummer...

[PlainBill]

Re: Lg 50ps3000 with flashing standby light

thanks for the answer, but i live in the uk, seen the boards on the us ebay but not sure if they will work in a uk tv (voltaged differance not sure) found a few sites in the uk but they all out of stock and when i contact them they are also having problems getting hold of the boards..lol looks like i may have to give up on my lovely 50 inch lg tv,, what a bummer...

Any voltage differences are handled by the power supply. There are also differences in the broadcast signals, that is handled by the main signal board. The Y-sustain, Y-buffers, and Z sustain should be the same for all countries. LG uses a white label for the part number. It begins with 6871. (An example - the Z-sus for a particular 42" plasma TV is 6871QZH956A). Select by the full part number to ensure compatibility.

PlainBill

[pete ling]

Re: Lg 50ps3000 with flashing standby light

Hi I have just been working on my 50ps3000.
(No picture but sound & flashing lamp).
Removing the ZSUS board made no difference.
however I tested board and found several Mosfets s/c including the ones available in a kit I have since seen advertised.
after repairing the ZSUS board I then looked at the 15vdd voltage and found this was missing. this turned out to be a faulty chopper Mosfet on the YSUS board, i replaced this and the set is back running again. I do however have issues with the temperature of Q13,14 &15. I have replaced all 100uf caps on the control board (also available in the kit I have seen) but the heat issue I have is still under investigation.

I am not implying that your set has the same problems as mine but worth a look. However please remember you are working with very high voltages around this area of the TV and you should only do this if you are qualified / competent to do so.

[Ven]

Re: Lg 50ps3000 with flashing standby light

Hi I have just been working on my 50ps3000.
(No picture but sound & flashing lamp).
Removing the ZSUS board made no difference.
however I tested board and found several Mosfets s/c including the ones available in a kit I have since seen advertised.
after repairing the ZSUS board I then looked at the 15vdd voltage and found this was missing. this turned out to be a faulty chopper Mosfet on the YSUS board, i replaced this and the set is back running again. I do however have issues with the temperature of Q13,14 &15. I have replaced all 100uf caps on the control board (also available in the kit I have seen) but the heat issue I have is still under investigation.

I am not implying that your set has the same problems as mine but worth a look. However please remember you are working with very high voltages around this area of the TV and you should only do this if you are qualified / competent to do so.

I have same problem, and already ordered the set from Ebay. What was the issue with overheating of transistors ? What happened so then you noticed transistors are too hot.

On my one 17 Volt is ok, but there is no Z-bias voltage, apparently it should be 95 Volt.

[ReeceyBurger123]

Re: Lg 50ps3000 with flashing standby light

Replace the transistors on the Zsus heatsink as well ad the resistors in the kit. To fix the overheating of them replace ALL the 100uf caps on the control board and the little 47uf 50v cap on the Zsus near the heatsink with the failed transistors.