TV Repair

[Dusty]

Hello Forum,

A few nights ago when I turned on my Samsung TV I heard a loud POP and noticed a slight burnt smell. Of course my TV didn't turn on after that anymore.

I opened up the TV and found a blown disk capacitor on the power supply board (see attachment 1). Now I thought before I buy a new TV, why not try fixing that one since it seems that only one small part broke. I'm not an electrician and my electronics knowledge is quite shallow but I have some basic soldering skills and I can probably replace that broken capacitor without ruining the whole board. But before I do that I have a few questions and uncertainties that I need help with and I am hoping someone can answer them here:

1. There must be a reason that capacitor exploded, right? Is it common that they just fail on their own? Is the blown capacitor just the result of a bigger underlying problem? And since its the power supply I guess the chances are quite high that much more got fried.

2. What kind of disk capacitor is that? I checked google for "22K 1KV" and some say the "K" is for the tolerance, some say its the classic "kilo". Now I am unsure what to buy. I can't find any with the same marks as mine. I checked other capacitors on the board and there is one more with the same markings (see attachment 3). Just to be sure I didn't miss anything on the blown of part.

3. Is there a risk in fixing the board? I don't want to burn down my flat and I am kinda nervous thinking about the voltages that run through that board. I checked eBay and there are used power supply boards available for my TV for around 40€. Still much cheaper than a new TV.

I would be really thankful for some advice.

Thanks!
Alex

[m3vuv]

looks like its possbly a tantalum,they die in flames normaly,just renew it and try t.

[wraper]

Should be 22 pF 1kV. K is not used to indicate unit of value on capacitors, so most likely indicates 10% tolerance.

[Gyro]

looks like its possbly a tantalum,they die in flames normaly,just renew it and try t.

You don't get 1kV tantalum beads.

[inse]

22pF 1kV ceramic disc capacitor, just give it a try - if anything else is toast, you would not have wasted much.
Did you also check for a blown fuse?

[wraper]

Also I don't think it's the only part which broke. Looks like it's used in snubber circuit in SMPS. And likely as it failed it also blew a MOSFET, possibly together with PWM controller (or PWM controller IC which has built-in MOSFET).
EDIT: adjacent IC is SQD2011K. No datasheet or schematic available but it's a PWM controller with a built it MOSFET, so most likely it failed too. Also you need to check adjacent diodes as well.

[BrokenYugo]

I'd recommend the used eBay board option, odds are that will get the tv going again. If you're asking what risks there are here in general, you aren't ready to play with such high energy circuits, the hot side section of a switching power supply can easily kill you.

[Ground_Loop]

It's a tant. They're know to spontaneously self destruct. Just get another one and give it a go. Don't let the hyperbole put you off.

[TheMG]

It's a tant.

Nope, definitely not. That's a ceramic disc cap. 1kV 22pF. Tantalum caps aren't available with voltage ratings anywhere near that high. Also they are polarized and this clearly has no markings indicating polarity.

[Ground_Loop]

My mistake. Should have expanded the thumbnails.

[Manolo Mos]

I bet it is 22nF 1KV

[james_s]

I'd recommend the used eBay board option, odds are that will get the tv going again. If you're asking what risks there are here in general, you aren't ready to play with such high energy circuits, the hot side section of a switching power supply can easily kill you.

I was going to suggest this too, at least if you are not well versed in troubleshooting. It's worth a look anyway, it's common enough for the LCD panel to get broken that there tend to be a lot of boards out there from scrapped TVs.

[CaptDon]

Any idea how big 22n at 1kv would actually be? It's 22pf