LG 50PC3D-UD power issue

[retiredcaps]

Re: LG 50PC3D-UD power issue

It shows less than 15ohms resistance between each pin, in both directions, which is different from the other similarly labeled components. Theres also a box capacitor next to it that is caved in on the sides.

Remove the component and verify "out of circuit" that it is shorted. Sometimes a low ohm resistor or some other component will cause false readings while "in circuit".

The store sells mostly NTE parts, for future reference, are NTE caps generally of good quality?

You want to stick with these electrolytic brands listed here ...

https://www.badcaps.net/forum/showthread.php?t=2280

[nswizdum]

Re: LG 50PC3D-UD power issue

Remove the component and verify "out of circuit" that it is shorted. Sometimes a low ohm resistor or some other component will cause false readings while "in circuit".



You want to stick with these electrolytic brands listed here ...

https://www.badcaps.net/forum/showthread.php?t=2280

Yep, I have already removed it and tested it, same result.
I'm having a hard time finding a spec sheet though, are there any places I should be checking besides http://english.electronica-pt.com/? I found a few people selling them on ebay, but purchasing electronic parts on ebay is a bit like purchasing prescription drugs from a street corner, no idea whats actually in it.

[retiredcaps]

Re: LG 50PC3D-UD power issue

I found a few people selling them on ebay, but purchasing electronic parts on ebay is a bit like purchasing prescription drugs from a street corner, no idea whats actually in it.

If you buy from

http://cgi.ebay.com/SD20N60-power-MO...134472#vi-desc

Coppell TV repair is very reputable. They have a blog that gives alot of repair info. I know PlainBill visits their blog. See http://blog.coppelltvrepair.com/

If you want info, send them an email and I'm sure they will respond back to the auction. Also note the details they give in the auction about checking the lower power components in the drive circuitry.

I personally would have no hestitation in buying from them.

[nswizdum]

Re: LG 50PC3D-UD power issue

No dice, still the same problem after replacing that mosfet.

[nswizdum]

Re: LG 50PC3D-UD power issue

Well, that was fun. I powered the TV on again to check some more points, and when I started testing points, there was a really loud pop (ceramic fuse blew). 4 of the power mosfets on the first heatsink bit the dust as well. I think it may be time to buy a new power board, 4 mosfets is $40, and I still don't know what the original problem was.

[nswizdum]

Re: LG 50PC3D-UD power issue

Well, that was fun. I powered the TV on again to check some more points, and when I started testing points, there was a really loud pop (ceramic fuse blew). 4 of the power mosfets on the first heatsink bit the dust as well. I think it may be time to buy a new power board, 4 mosfets is $40, and I still don't know what the original problem was.

Upon further inspection, it appears that the fuse was blown when electricity arced from one of the mosfet solder points on the bottom of the power board, to the back of the plasma panel. I had it in the proper mounting holes, what would cause that? Some kind of overload?

[JSK-MX]

Re: LG 50PC3D-UD power issue

Following this with interest because I have the exact same tv and problem. Replaced the 9 bulging 10v3300uFs on PS, but no luck. On control board D15 on the Temperature Diode stays green, D17 lights immediately after and buzzes, then shut down. Any quick help? And to OP, did you fix the thing? Thank you.

[nswizdum]

Re: LG 50PC3D-UD power issue

Following this with interest because I have the exact same tv and problem. Replaced the 9 bulging 10v3300uFs on PS, but no luck. On control board D15 on the Temperature Diode stays green, D17 lights immediately after and buzzes, then shut down. Any quick help? And to OP, did you fix the thing? Thank you.

I did eventually get it fixed (with help from Coppell TV Repair). It was one of the MOSFETs causing my problem. I broke my rule of "no soldering after midnight". A bead of solder dripped off the MOSFET pin and shorted a connection that was hidden under the heatsink. That was what caused the sparks and blew a bunch of the MOSFETs again. Still happily using that TV now.

[CAnderson]

Re: LG 50PC3D-UD power issue

I have a similar problem with the 3 flashes of green. I replaces the caps but still nothing. I however don't have the control board LEDs lighting up at all. What would keep them from working/ getting power?

[caspermccormack]

Re: LG 50PC3D-UD power issue

Hello, I too have the same board in my Lg 50PC1d plasma, At first the Ysus was replaced and both buffers were checked out and are in working order. However the problem I now have is the power board won't stay switched on (5 seconds before it switches off). I looked for the voltages from the Va and Vs and found that the Vs briefly hits 56.4and drops before it knocks off and the same for tha Va (17.3). The relays that click for on/off are at the bottom of the board, could these be the problem?


Thanks inadvance,

Anthony

[TechShui]

Re: LG 50PC3D-UD power issue

Hello casper,

Have you tried unplugging the Z board to see if the TV stays on for longer than 5 seconds?

[caspermccormack]

Re: LG 50PC3D-UD power issue

Hello casper,

Have you tried unplugging the Z board to see if the TV stays on for longer than 5 seconds?

Not yet, I'll give it a try and post back.

Cheers

[caspermccormack]

Re: LG 50PC3D-UD power issue

Hello casper,

Have you tried unplugging the Z board to see if the TV stays on for longer than 5 seconds?

Still the same as before with the Z board unplugged. I am missing both Va and Vs voltages, all the other voltages are there and all the grounds.

[ford2008]

Re: LG 50PC3D-UD power issue

I did eventually get it fixed (with help from Coppell TV Repair). It was one of the MOSFETs causing my problem. I broke my rule of "no soldering after midnight". A bead of solder dripped off the MOSFET pin and shorted a connection that was hidden under the heatsink. That was what caused the sparks and blew a bunch of the MOSFETs again. Still happily using that TV now.

Can you please indicate how you test/diagnose this bad fet (on/off board?)and which one need to be changed on YSUS # 6871QYH039A, as i changed ipm and it GOT burned again and i suspect of Fet K2673 which got very hot. i want change new IPM202 on Y AND Z SUS need to know if other component such as fets need to be changed. i couldn't find online replacement Fet K2673 on YSUS # 6871QYH039A, is there any advice please.
see attached Y SUS include suspected Fet pic

[cheebster]

Re: LG 50PC3D-UD power issue

Anyone can correct me if im wrong, but this one :

http://www.digikey.com/product-searc...9497-5899-5-ND

Seems a good replacement. STW9NK70Z is the part number. I've seen those fets shorted on my bad ysus here and you really need to check everything around it since it usually brings a few smd resistors with it, as well as some diodes marked es1g nearby. Multimeter is a must on this one