My TV burned out, so i opened it up and the C311 capacitor looks like is dead. Googled the DELTA DPS-245BP schematics and all they have is an asterisk symbol next to the name. Would really appreciate if I can get some help identifying the capacitor spec.


Thank you

 

Could mean a MKP4 or similar spec.
Should be a note somewhere tying in the reference.

 

Could mean a MKP4 or similar spec.
Should be a note somewhere tying in the reference.

Hi Max, I was able to find more information on another Sony board calling it out as a 330pF K. So is the Voltage for the cap going to be 450V?

 

MKS4 or MKP4, what is the voltage they are being subject to?
Max.

 

The schematic shows C310 as being the same rating as C311.

 

MKS4 or MKP4, what is the voltage they are being subject to?
Max.

Max, I was finally able to get a good pic of the cap, looks like 1KV



the cap label and the schematic do not match?

 

Also appears to be ceramic?

 

Also appears to be ceramic?

when i test it i get 0.33NF

not sure if i should buy the 221K or the 331K cap for replacement

 

My TV burned out, so i opened it up and the C311 capacitor looks like is dead.

What makes you think it's dead?

Better to fully diagnose the problem before you start buying parts. If you just start buying and replacing parts soon enough you'll have a new TV for your remote.

 

Looks like a HV snubber cap, the other one is likely blown to bits and unreadable. The * is likely to a note about selection. If you order might as well get two and replace both with fresh caps, and go for a higher voltage, e.g. 2kV or 3kV. Exact capacitance value is not critical but get both the same.

 

What makes you think it's dead?

Better to fully diagnose the problem before you start buying parts. If you just start buying and replacing parts soon enough you'll have a new TV for your remote.

Good question Tony,

Visually, the back of the cap is gone.

 

Looks like a HV snubber cap, the other one is likely blown to bits and unreadable. The * is likely to a note about selection. If you order might as well get two and replace both with fresh caps, and go for a higher voltage, e.g. 2kV or 3kV. Exact capacitance value is not critical but get both the same.

I posted a picture, yes one is blown. My problem is that the schematic and my meter calls for a 331 capacitor, but the capscitor photo calls for a 221 capacitor. I don't understand which one is the correct only (is it possible to print wrong number on the capacitor?). And which one should I replace it with?

 

Appears to be disc ceramic, apparently subject to H.V. ensure you obtain one with a much higher rating.
Max.

 

Think about what purpose these caps serve to function--they are snubbers used to provide a bleed path for a high voltage spike at the front edge of an inductive kick (V=-L x dI/dt) when the FET switches off, so the most important aspect is the voltage rating should be as high as you can find.

The capacitance value is down in the 200-300 range of picoFarads because the time period "dt" is very short and the corresponding frequency for reactance calculations is very high. So any capacitance value in this range will be sufficient and they are typically available in standard values, e.g. 100, 220, 330, 470pF with 10- 20% tolerance. 221 or 331 (220-330pF) are essentially equal in this situation. Ignore your meter reading-- unless it is a precision LCR meter that can measure across various frequencies the tolerance variation will be too difficult to measure.

Unless the blown cap is reading as a short circuit, this was likely a symptom and not the cause of your issue. Check the Q302 FET and all the other fets and diodes in your schematic picture for damage. When a snubber blows generally something else goes too. Whether or not that cap is in the circuit would not be the cause for the unit to not power up--there is something else failed too.

 

Good question Tony,

Visually, the back of the cap is gone.

View attachment 231197

Good answer.

I asked because sometimes people come here asking for help and believe they know what the problem is. They can end up spending a lot of money "Guessing" at what the problem is. I always suggest fully diagnosing the problem before replacing components. Another common warning I give is that you need to understand WHY the component (this case a cap) failed.

No joke! I've seen people replace a fuse over and over hoping that it's a problem with the fuse when in fact there is something else drawing massive amounts of current. I'm not suggesting that's your issue; just pointing out that not always are we dealing with sharp tools from the shed. But obviously from your picture - - - . Nuf said.