Little help with part to repair plate amp?

[Hdale85]

Hi guys, I have this BASH plate amp and it stopped working, pulled it opened and this part is quite obviously blown. I think it's a cap? It's rectangular but looking it up there seems to be quite a few different kinds and just not sure what to replace it with. Here's a picture.



Any help is appreciated. The numbers on it look like 105k.

[Alaric]

I'll check my parts collection(s) and see if I can come up with anything.

[Hdale85]

Ok cool. I've been looking for something to order but I'm not sure if it needs to be the exact part, or if maybe there is a beefier part so that this doesn't happen again lol.

[Alaric]

I'm pretty sure it's a cap , but there are so many caps out there it's a friggin' Easter egg hunt when something like that happens.

[TEK]

You should see if you can get your hamds on a service manual for the amp. That would probably have the info...

[BobEllis]

It looks like a film capacitor. Not a part known for explosive failure when operated within limits. Something else could have failed taking out the cap. Is that transformer insulation blackened or is that just the light? Have you done a web search for "capacitor failure" in your amp? If it's a common issue there's likely a thread somewhere.

If you choose to just replace the part keep something solid between you and the amp when you power it up. We don't want to hear about shrapnel wounds.


This may help you identify the part. http://www.carli-cap.com.tw/en/ProductView.asp?ID=62 If it's an X2 cap exploded like that something is seriously wrong.

[Hdale85]

Looking over the board I can't really find anything else that looks like it's been damaged at all? I did find a website showing many different types of film caps from Carli, but this one is a bit different. For one the text on it is a bit more generic looking...and plain. It only has 2 line of text where the other carli caps on the board look more like what's in your link with tons of info on it. The transformer is not blackened at all. Honestly I kind of wonder if that cap is a knock off or something? I've seen other picture of the same amp and that cap is a completely different color and brand.

[BobEllis]

Without a service manual or at least a schematic you're really just shooting in the dark. Other than as a learning experience, it seems replacement would be the the best value proposal.

[Hdale85]

Replacement is the best value? I don't currently have money to replace it, which is why I figured I'd just try and replace this part since it seems like it's probably a few dollars. Christmas time is a money suck, we won't have much money until feb probably lol.

I've looked all over for schematics or service manuals and can't find anything.

[Hdale85]

Looks like these though http://www.carli-cap.com.tw/en/ProductView.asp?ID=31

[JonMarsh]

The key things are the working voltage rating, the value (105N is 0.1uF) and the lead spacing for the capacitor body. I'd suggest removing the cap from the PCB to check that. Check the traces and see if it is connected in parallel with that 680uF 200V electrolytic- if so, that gives you the clue you need for the minimum breakdown or working voltage. Otherwise, check the capacitor body. It COULD be that the cap just failed, but film capacitors are usually very reliable- of course, they likely don't use any more expensive parts than they think they can get away with.

First step, pull the cap, photograph on both sides, measure lead spacing, and get back to us with that info....

[Hdale85]

OK, thanks Jon. It looks like it did say 250v at some point as I can see a 2 lol.

[Hdale85]

Waiting for my new soldering station to show up, so I'll get back to you with that pic.

[Hdale85]

Got the board off, seems like this board is likely the PSU section, as the amp section seems to be attached to the metal plate for the heatsink, then there is another board on the side that's the input board.

[JonMarsh]

Given the electrolytic cap configuration this looks like a classic half wave voltage doubler; with low range AC line, it's half wave rectification to get 330VDC, with 220VAC, it's full wave to get 330VDC. The 250V electrolytic caps are in series, and I'm certain your supposition is correct, this is the power supply side. Is there a blown fuse on the primary side somewhere, too?

[Hdale85]

The only fuse I see anywhere is the one on the power input which is fine. the amp still comes on, the LED's come on and everything, so it seems like this particular section of the SMPS feeds the amplifier board.

I forgot I had this radio shack desoldering iron but I can't get it to work. It gets hot but it just doesn't seem to be melting the solder joint. Just going to have to wait for my new soldering station to show up to disassemble. Looking at the PCB it seems that cap goes to a diode and then connects to on of the traces that goes to the bigger caps.

[Hdale85]

Ok I finally got my soldering station and removed the part. Here are the pics.

[jim1961]

It looks like a film capacitor. Not a part known for explosive failure when operated within limits. Something else could have failed taking out the cap. Is that transformer insulation blackened or is that just the light? Have you done a web search for "capacitor failure" in your amp? If it's a common issue there's likely a thread somewhere.

If you choose to just replace the part keep something solid between you and the amp when you power it up. We don't want to hear about shrapnel wounds.


This may help you identify the part. http://www.carli-cap.com.tw/en/ProductView.asp?ID=62 If it's an X2 cap exploded like that something is seriously wrong.

Looks like it to me. If so, there could be too much damage to try and fix.

[Hdale85]

The transformer is not blackened at all. I said that already.

[Hdale85]

I did find that one of those big caps there that were next to it, not the closest one but the one in the back has a flat side? So it's not perfectly round.....which I've never really seen before?

[sdl2112]

You may have a bad electrolytic as well.

The small cap is 1uf, 10%, the small 2 I see in the photo was probably 250V. The 105K number can be broken down by the first two digits are the value, the third the multiplier and the letter is the tolerance...so 10*100000 pF or 1uF, K = 10% tolerance.

[Alaric]

I came up craps in my stash. I'll open up some PSUs and see what's there.

[Hdale85]

Yeah I don't really like how it seems to have exploded in there, kind of flaky on the stuff that took some of the blast and has what looks like smoke residue or something on them. I don't know I may have to just wait until after the holidays and get a new amp, maybe something that isn't a plate amp.

[Sergio]

He logrado resolver el problema, tuve el mismo fallo y simplemente reemplace el capacitor.