YSUS EBR73561201 clicking off on a LG 60PV400

[goldbird78]

Hi all, I have a EBR73561201 Ysus board on a LG 60PV400 that clicks off after 2 seconds when powered up. I am 99% sure the problem is the YSUS board because when I power up the TV with it disconnected the tv stays on and I have tested the buffers and when the buffers are disconnected and the YSUS is powered the TV shuts down. I did replace a couple of FGPF4633 transistors that were shorted and tested all gate resistors but it still will shut down once I hook up the ribbon cable from the control board. I retested the transistors I replaced and tested the gate resistors and they seem fine. Anyone know where else to look on the YSUS board or what other components are replaced when purchasing the repair kits for these boards. Thanks

[lookimback]

Re: YSUS EBR73561201 clicking off on a LG 60PV400

I'm working on the exact same board right now. I fixed it before and it worked for 6 months. Check all the RF2001 diodes . Some are attached to heat sinks, a couple aren't. When I fixed this before, it was some RF2001's, Some FGPF4633's, some gate drive ICs (FAN73711) and there's some npn/pnp transistor arrays which were also bad. Can't remember the original PN, but I replaced them with CPH5506-TL-E. Both boards had issues. Right now I no longer am popping FETs, but still no picture or even pre charge flash. Both boards hum.

[goldbird78]

Re: YSUS EBR73561201 clicking off on a LG 60PV400

I found 3 more FGPF4633 transistors on the silver heatsink in the middle of the board that were shorted, I didn't see these at first because they were completely covered with the silicone goop. I replaced them and now the tv is working. I have tested it for over 30 minutes.....So far so good. I tested all the gate resistors and surprisingly they were good.

[lookimback]

Re: YSUS EBR73561201 clicking off on a LG 60PV400

Good job! I found two bad resistors, and two more bad FGPF4633s on the Y smd Z boards, but I still have a short somewhere on the Y. I use a lightbulb in series with VS ro limit current so I don't blow the replaced FETs. It's odd because it lights dim, then goes out, and that's the expected behavior, but then about a second later the bulb comes on bright and stays on.

[goldbird78]

Re: YSUS EBR73561201 clicking off on a LG 60PV400

Have you checked all the 270 gate resistors on the 4633 transistors ? they should read about 13.5 ohms when in parallel. Surprisingly mine were fine but they usually blow when the resistor shorts.

Good job! I found two bad resistors, and two more bad FGPF4633s on the Y smd Z boards, but I still have a short somewhere on the Y. I use a lightbulb in series with VS ro limit current so I don't blow the replaced FETs. It's odd because it lights dim, then goes out, and that's the expected behavior, but then about a second later the bulb comes on bright and stays on.

[lookimback]

Re: YSUS EBR73561201 clicking off on a LG 60PV400

Checked them all. Last time some were bad, but not this time. I notice VSC is only 12v. Possibly it would be higher if I wasn't using the lightbulb limiter, but definitely still quite low.