Blown 104 ceramic caps enough to knock out a channel?

[mikay786]

Just looking at this prosound 1600 amp which from initial testing has a fully dead output (2 channel amp) and another that works but no bass.

Anyhow there's two ceramic caps 104 100v right next to the main filter caps and internal fuses. Was wondering if these have the potential to be the culprit or are they too insignificant?

I ask as if I remember correctly on the gale sub that I repaired which had the same ceramic caps blown, I remember folk saying it would still work without them.

[budm]

Re: Blown 104 ceramic caps enough to knock out a channel?

Those two fuses would have blown if they are shorted out, but you must be getting the Voltages from the filter caps otherwise none of the channel should be working so the caps are not shorted out.

[mikay786]

Re: Blown 104 ceramic caps enough to knock out a channel?

They don't look blown, but I'll check them.

Correction

One channel is noisy and very very low volume

Other has loud volume but no bass what so ever

I'm guessing the ceramic caps are to reduce noise? Decoupling

[stj]

Re: Blown 104 ceramic caps enough to knock out a channel?

ceramics can short, but if they are across the power they will explode or blow a fuse or something.

[mikay786]

Re: Blown 104 ceramic caps enough to knock out a channel?

I see what you mean, the fuses inside are good but they have been replaced by former owner so probably blew and replaced. Although they are 15a but should be 10a.

I've got some 104 100v ceramics from last time so will replace and see if that helps.

There's also a 120ohm 3w resister on the output board that was a bit worse for wear but removed and measured and seems ok. Will replace anyhow

[mikay786]

Re: Blown 104 ceramic caps enough to knock out a channel?

Can you test main filter caps with a multimeter or that eBay jobby esr meter?

I've tried before with other filter caps but couldn't get a reading with multimeter. Was thinking it didn't have enough oomph to charge then?

[mikay786]

Re: Blown 104 ceramic caps enough to knock out a channel?

Got both channels to works without any noise, and the low channel is now at the same volume of the other.

Still no bass, but ive got a sneaky feeling that might be to do with my input which is a 3.5mm jack from back of pc to full size jack into amp.

Going to try with a dedicated cd player using the amps xlr inputs.

[mikay786]

Re: Blown 104 ceramic caps enough to knock out a channel?

Yep going through XLR inputs and working a charm (Phono out from CD player to XLR in on amp), wondering if the full size jack inputs are faulty or just not compatible / playing nicely adapted from PC.

Cant believe just two tiny 100nf caps was the problem!