LG 60PZ570 Repair

[sean0118]

Hi everyone,

In the process of repairing an LG 60PZ570 plasma.

It was shutting down after a few second originally, but I re-soldered cracked solder joints on Q801 on the main power supply (middle board), L201/L202/L203 inductors on ZSUS (right board) and Q417 on VSUS? (left board). Now it stays on but with black patches on screen...

I examined the ZSUS and found fuse FS103 (6.3A 250V) was blown, and at least 3 shorted FGPF4633 IGBTs in the 200V switching circuit:







Two 10ohm resistors on the gate of one of the IGBTs are burnt:



What I'm unsure about, is what I need to replace in the driving circuit. There's two 8pin FAN73711 driver ICs, each connected to the IGBT gates through some 5pin transistors marked '5 K', anyone have a part number for these?

The 47uF 25V highside bootstrap capacitor C212 also only reaches ~0.8V when using the multimeter in diode test mode, but I've only tested it in circuit, should I replace it too?

edit: Couldn't see any zener diodes to protect the gates from over voltage... maybe I could add some?




So at the moment I'm planning on ordering a replacement 250V slow blow 6.3A fuse, FGPF4633 IGBTs, 10ohm resistors, FAN73711s, the 5pin IC (once I have a part number), some 47uF 25V capacitors and maybe some 220uF 250V to replace the main filter capacitors. Anything else I should replace?

Also, what is the cause of the failure? The cracked solder joints around the inductors? Anyone have a schematic?

[sean0118]

Re: LG 60PZ570 Repair

Sorry if my first post was too long/confusing.

My main questions were:

1. What's the part number of the 5pin transistor (marked with '5 k') in the IGBT driver circuit?

2. Are there other parts that commonly need to be replaced once the IGBTs have shorted?

[sean0118]

Re: LG 60PZ570 Repair

Good news, both IC215 and IC216 which are marked '5 K' are Toshiba HN4B101J common emitter NPN/PNP drivers...

Can't find them in stock anywhere, but will try replacing them with ON Semi CPH5506... "What's the worst that could happen???"

[sean0118]

Re: LG 60PZ570 Repair

Repair went smoothly - it works perfectly now!


(One lead of a FAN73711s didn't solder properly, when I powered it up it would make a high pitched squeal and turn off a second latter, but I resoldered that pin and now it's all good)

[supers]

Re: LG 60PZ570 Repair

Hi there,

First off; great write-up! I found it very informative.

Anyway, I have the same symptoms you described at the start of your troubleshooting (shuts down after a few seconds). I've pulled out the ZSUS board and the same 3 coils have cracked joints.

Your repair summary appears to mirror the repair kit offered at this site (http://www.shopjimmy.com/lg-ebr73561...pair-kit.htm); 1 fuse, 6 transistors, 4 ICs (look just like the ones you've identified), and 12 resistors.

Since I'm lazy, I was hoping I could just ride on your coattails and order the same parts as you did. I've tried to piece together a summary of what you did. Could you please take a look and see if the following is accurate?

Repair Summary:

PSU Board:
1. Inspect and resolder any cracked joints (e.g. Q801)

YSUS Board:
2. Inspect and resolder any cracked joints (e.g. Q417)

ZSUS Board:
3. Inspect and resolder any cracked joints (e.g. L201-203)
4. Replace FS103 (6.3A, 250V). What part did you order?
5. Replace Q208-Q213. Fairchild FGPF4633 is discontinued; were you able to locate some or did you source an alternate?
6. Replace R250, R254 (10Ω, 0603)
7. Replace IC204 & IC213. Fairchild FAN73711MX
8. Replace IC215 & IC216. Toshiba HN4B101J is disconintued and can be replaced with ON Semiconductor CPH5506-TL-E.
9. Is it necessary to replace C212 (25V, 47uF)?
10. Is it necessary to replace C111-C115, C131 (250V, 220uF)?
11. Did you add any zener diodes?
12. Anything else??

Also, I'd appreciate any advice you have for removing the hard-to-reach components (e.g. Q211, did you remove the black heatsink?)

Thanks for your help!

[supers]

Re: LG 60PZ570 Repair

A follow up of my successful repair:

TV Model:
60PZ550-UA.ACCLLUR

Problem:
The TV would automatically power down a few seconds after being powered on. The screen never turned on.
Prior to this behaviour, the image quality was degraded, with areas that flashed a purplish grainy colour off and on (more often that not).

Issues Found on ZSUS board (EBR67820001, PCB: EAX62076601, Rev G 100920)
1. The ZSUS board exhibited cracked solder joints around the 3 large inductors L201-203
2. Fuse FS103 was open.
3. Q208, Q210, & Q212 were all shorted out on the PCB. Once the components were removed from the board, only Q208 was actually shorted out and the other two were functioning correctly.
4. Q209, Q211, & Q213 were all shorted out on the PCB. All three IGBTs were defective once removed from the board.
5. R250 & R254 had been discoloured due to high temperatures. The resistors still measured the correct resistance at room temperature.

Corrective Actions Performed on ZSUS board:
1. Re-soldered Inductors L201-L203
2. Replaced FS103
3. Replaced Q208, Q210, & Q212. If you're going to perform this repair, just remove Q208 first and then recheck the other IGBTs in circuit (they may be ok)
4. Replaced Q209, Q211, & Q213. I recommend removing the 3 red/brown capacitors directly in front of the IGBTs to provide clear access to remove/install them.
5. Replaced R250 & R254.
6. Replaced IC204 & IC213. I'm not sure if these need to be replaced as I don't feed like bench testing the old units.
7. Replaced IC215 & IC216. I didn't check these components when they were installed in the circuit and just replaced them based on the original poster's comments. That said, checking them on the bench, nothing is shorted and using the diode function on the multimeter indicates that they are all ok and didn't need to be replaced.

Corrective Actions Performed on YSUS Board:
1. Resoldered large inductors (they weren't cracked but I figured it couldn't hurt)

Components Used:
2. FS103: Littelfuse 021506.3MXESPP
3 & 4. Q208-Q213: Fairchild FGPF4633 (purchased from Rich Tech Electronics http://richtechparts.com/index.php?r...earch=fgpf4633)
5. R250 & R254: Panasonic ERJ-P06J100V
6. IC204 & IC213: Fairchild FAN73711MX
7. IC215 & IC216: ON Semiconductor CPH5506-TL-E

Other thoughts:
I purchased some small 30mm, 13dB fans (Copal Electroniocs F310R-12LLC) and installed them in front of the IGBTs that failed to try and improve airflow around them. On their own, the fans are silent, but when they are installed in the system (via a 3D printed bracket attached to the input board shield), they become very loud. I imagine that they are vibrating the mechanics and a much larger surface is vibrating, which makes them loud. I may end up cutting a hole in the rear cover and directly mounting a 90mm or 120mm Noctua fan to provide increased flow with (hopefully) less noise.
Currently, the fans have a PS that is patched just after the relays on the main PSU board so they only run when the TV is powered on. That part of it works well; I'm just not sure I can live with the noise!

[jetadm123]

Re: LG 60PZ570 Repair

Thanks for sharing and giving replacement parts numbers. Helps takes the mystery of what's in some of those "kits".

[sean0118]

Re: LG 60PZ570 Repair

Sorry I just noticed this thread has replies... congrats on your repair Supers.

As far as I can remember, I didn't replace any capacitors, couldn't find issues with any of them.

I didn't remove any heatsinks, they are large enough that they would be very difficult to unsolder. Instead I just unscrewed the components from the heatsink and bent them forward slightly so they were no longer making contact with it, you can then unsolder the IGBTs etc without the heatsink wicking the heat away

There were two 10ohm resistors in parallel (5ohm effective resistance) in series with each IGBT gate, I had to replace two which were fried, all the others were in spec though.


Just in case anyone is interested, my parts list was:

Mouser:
Fairchild - IGBT - FGPF4633TU (these are no longer stocked )
Littlefuse - 250V 6.3A - 021506.3MXEP
Susumu - 0805, 10ohm - RG2012Q-100D-T5
Fairchild - gate driver - FAN73711MX


Digikey
On Semi - NPN/PNP driver stage - CPH5506-TL-E

[lynchkb]

Re: LG 60PZ570 Repair

I am currently undertaking the same repair. The issue was the picture went out but tv would still power on and sound was still there.

I removed all three main boards and the power board solder joints were fine, ysus board had cold solder joints on some of the inductors so i resoldered all of them but the fuse was not blown so i assume the board is fine.

The Zsus had the fuse blown so i removed it, Q208-Q213 were all blown so I removed them, R254 was dark but still within specs. I also have removed IC 204, 213, 215, 216.

I am waiting on the rebuild kit from shop jimmy, it arrives tomorrow. I will solder up the parts mentioned above.

Is there anything I should check prior to either reinstalling the board or powering up the tv?

[freakaftr8]

Re: LG 60PZ570 Repair

Just remember install every single screw tight in these sustain boards before powering up after your repair. These boards have floating grounds and if not every ground is connected it will blow up your board again.

[ajshoe]

Re: LG 60PZ570 Repair

R250 on my EBR67820001 board is a 47 K resistor, I believe you meant R260 and R254 which are 10 ohm resistors. These tow resistors are in parallel to the fgpf4633.

[ljintexas]

Re: LG 60PZ570 Repair

Freak is right on. I have repaired three of these and all screws are always loose to the point that I can turn them 1/2 to 3/4 of a turn with just a hand driver.