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Repair service for 50'' LG 50PC3D Y-MAIN / YSUS board causing blinking display or no display or, sometimes, TV not wanting to power on at all

Coppell TV Repair offers a REPAIR SERVICE for your 50'' LG 50PC3D YSUS board as shown on the picture.

REPAIR SERVICE means you have to send us your malfunctioning board that we will attempt to service, test and return back to you.

Failure symptoms

There are several different ways the YSUS board in LG 50PC3D can fail and there are therefore several different manifestations of those failures.

Many of the failure symptoms described below are not unique to that board, so be advised that while increasing your odds to diagnose it properly they do not guarantee it.

1) Flashing display
Usually accompanied with "ticking" coming from the YSUS board, about once every second, in sync with the blinking display, this failure indicates one of the two large ICs on the board has failed.
We replace both ICs, though, since the still live one is not too far from failing either.

2) No image on display (black screen), sound possibly present
Sound is actually likely working fine even if you do not hear it as it is easy to lose proper input and therefore sound if you see nothing on the screen and start pressing buttons in hope to bring it back to life.

This is a typical YSUS failure symptom in many plasma TVs.

For double-checking it you may want to leave the TV to work for 4-5 minutes and test the temperature on the two heat sinks on the board - they should both be warm. If either heat sink is cold that indicates failed IC underneath.
The same test applies to the ZSUS board.

3) When powered on the TV clicks on followed by a quick click back off and never comes alive
While there are many possble reasons for this behavior there are just two in regards to the sustain boards: a blown fuse on the YSUS board (the ZSUS does not have its own fuses) or a failed and shorted sustain board (YSUS or ZSUS), but without having blown a fuse on the YSUS. Either condition would have the same result on the TV not willing to stay on.

Note 1: An open 4.0A fuse on the YSUS board does NOT automatically mean the board is bad! Since YSUS and ZSUS in 50PC3D are in parallel after the fuses it can be either one of them that caused the fuse to blow! 

Note 2: After confirming both fuses on the YSUS are good, you can try disconnecting the ZSUS from YSUS and try powering on again. If problem persists then ZSUS is probably not the source.

Note 3: You can use a digital multimeter to check each board's Vs to GND resistance on the power connector. A low resistance which is the same in both directions (Vs to GND and GND to Vs) indicates a faulty board.

Processing time

Typical processing time for the repair is within two business days; if we have any probems that require more time (be it overload or technical problems) we will contact you with an update and request for more time.

We have a fairly high success ratio, but we still do not guarantee success; if we can't get the board to work, though, you will not need to pay.


Presently we do not charge in advance for repair services.

Instead, once the board(s) are received, tested, found to be defective, serviced and tested again to success we send a payment request to the customer.

If something along the process - such as unexpected difficulty or finding a board to be functional - arises we contact the customer via email and/or phone and disscuss options.

Minimal charge / diagnostic fee

If a board arrives and is determined to be functional we charge up to $25 for diagnostic fee.

For explanation of why do we do that please read this article.

Board requirements

We ask that the board arrives here in good physical condition and without traces of tampering. If someone (other than us, that is) has already attempted to service the board then please contact us with a description/pictures and do not directly place an order. We reserve the right to refuse service to boards that have signs of repair attempts.

If you have any questions do not hesitate to ask.