Are these Chemi-con caps bad? (from a 2008-era LG Plasma that freezes)

[Capybara]

My 60-inch LG plasma from 2008, model 60PY3DF, has a problem where the picture freezes approx 30 seconds after turning it on and then maybe 20 seconds later, it sometimes will self-reboot.

I removed the TV's cover and everything looks ok (to my UNTRAINED eye) except for 2 Nippon Chemi-con 250V 820uF KMQ 105C capacitors. They are ever so slightly bulging on top.

I've taken 2 pics, one of these 2 250V 820uF ones and the other of another similarly sized but different spec'ed Chemi-con, 450V 390uf KMR 105C, that has a perfectly flat top, just for comparison's sake.

My questions are:

1) Could the 2 250V 820uF KMQ Chemi-cons, with the slight bulges, be bad? I am only basing this theory on the fact that there is a very slight bulge.


2) If these 2 caps are indeed bad, could they cause my TV's freezing and self-rebooting problem?


3) If these 2 caps are bad, what should I replace them with?

My readings of this forum suggest that Chemi-con caps are one of the "good" ones.

Should I get the same ones?

I do note that these slightly bulgy ones are marked "KMQ" and the other one is marked "KMR". Is the KMR better than the KMQ? I note that these KMQ caps have 3 "grooves", shaped like a Mercedes Benz sign, on top of the capacitor whereas the KMR (and pretty much all of the other caps in the TV) have 4 grooves, shaped like a plus sign.

Perhaps this is a sign that the KMRs are built differently from the KMQs?


4) I'm from Vancouver, Canada. Is there a good vendor who will sell me (ship me) 2 of these capacitors for a reasonable price and reasonable shipping charges?

Thank you from a new member!

[ReeceyBurger123]

Re: Are these Chemi-con caps bad? (from a 2008-era LG Plasma that freezes)

This series does have issues I have seen some blown ones in a hitachi before as well, chemicon apart from that are great caps replace them and your tv should be back up and running theres a chance that something els could be wrong but replace these first

[tom66]

Re: Are these Chemi-con caps bad? (from a 2008-era LG Plasma that freezes)

Those caps are for Vsus & PFC. If they went bad, the picture might get pink patches or sparklies, but should still "work", i.e. image should still move, TV should respond, etc.

[Capybara]

Re: Are these Chemi-con caps bad? (from a 2008-era LG Plasma that freezes)

Those caps are for Vsus & PFC. If they went bad, the picture might get pink patches or sparklies, but should still "work", i.e. image should still move, TV should respond, etc.

Thank you Tom. Sadly the picture is perfect. Even when it is frozen, the picture is perfect. So perhaps it's not these caps.

Do you think it's the main board? A year ago you had suggested it was the problem for a fellow with a Samsung with a similar freezing/rebooting problem.

See: https://www.badcaps.net/forum/showth...703#post443703

For my LG, there are 2 boards that look to be main boards. They are:

P/N: EAX42359101(0)
http://www.shopjimmy.com/lg-ebr39324...60py3df-uj.htm

or

P/N: EAX30428402
http://www.shopjimmy.com/lg-ebr32922...ctrl-board.htm

I'm attaching the pics for the 2 boards that I see (pics are from a vendor).

Do you have a suggestion for which one of the two it is more likely to be?

That fellow reported some success baking the board at 270C for 5 min. Is this a recommended tactic for me?

[tom66]

Re: Are these Chemi-con caps bad? (from a 2008-era LG Plasma that freezes)

I would focus on the main video board with the HDMI ports. In my opinion that would be most likely responsible. However it may be possible to test it. Do you see a header marked AUTOGEN on the other board (no HDMI ports)? This board is the control board and controls the sustain boards to generate an image on the plasma panel.

[Capybara]

Re: Are these Chemi-con caps bad? (from a 2008-era LG Plasma that freezes)

I would focus on the main video board with the HDMI ports. In my opinion that would be most likely responsible. However it may be possible to test it. Do you see a header marked AUTOGEN on the other board (no HDMI ports)? This board is the control board and controls the sustain boards to generate an image on the plasma panel.

Thanks for your advice Tom.

I took a chance and reflowed the solder on the main board using my oven.
And it worked!

It's been 3 days now and the TV continues to run perfect.

I understand that this type of home-brewed repair won't last forever, especially since the main (CPU?) chip will get hot when the TV runs and cools down when it's off.

And so I've tried to keep the extremes of this hot-cold cycling down by attaching an inexpensive 12V 80mm computer case fan to the grille next to the CPU heat sink and blowing air on it.

To reduce fan noise and to extend its life, I've slowed it down by powering it with a 5V wall-wart adapter I found lying around. The fan is now slow enough to be silent.

I have scheduled a periodic check to see if the fan still runs as I'm familiar enough with inexpensive computer fans to know they don't last forever either.

[tom66]

Re: Are these Chemi-con caps bad? (from a 2008-era LG Plasma that freezes)

Glad you found the fault. TBH my luck on "oven" reflows is pretty poor; I've had one graphics card reflowed four times. It works every time but a month later it fails. I'd investigate getting a replacement board if you find it fails again.