Damaged capacitors on amplifier

[Navy Guy]

I bought two of these B&O ICEpower amps that PE had on buyout several months ago: http://www.parts-express.com/bang-ol...4-ohm--309-250

I bought them when I was in Spain and had them shipped to my parents to store until I got home. I opened them up a week or so ago and found that one of the amps has two severely dented NPE capacitors on the board. I think it's in the power supply section, but I'm no amp expert. My question is, will a dented cap become out of spec or cause issues that could damage the amp. There doesn't appear to be an easy way to test the capacitors without removing them from the board, so if I'm going to do that I might as well replace them. I'll post pictures this weekend when I get a chance, but in the meantime, anyone know a good source of capacitors with both leads on the same end?

[dynamo]

I'm not an expert, no idea if the value will be affected, however seems reasonable that they would potentially be more prone to leaking or drying up if the can is tweaked enough to compromise the seal. I'd just replace them since they are so cheap.

No offense, but are you sure they are non-polarized? Most ps caps are polarized and can be bought anywhere, including pe

[dynamo]

I looked at the product photo and all the tall black caps appear to be polarized, negative indicated by the gray stripe.

Since the amps are NLA, a call to pe might result in them sending you some new caps to repair it..as we all know their customer service is great

[Navy Guy]

I'm not an expert, no idea if the value will be affected, however seems reasonable that they would potentially be more prone to leaking or drying up if the can is tweaked enough to compromise the seal. I'd just replace them since they are so cheap.

No offense, but are you sure they are non-polarized? Most ps caps are polarized and can be bought anywhere, including pe

I don't know that much about amps, so they very well could be polarized. I didn't really look closely. Just pulled them out of the box and saw the damage, then put it back in. The weird thing is, this wasn't a shipping issue with damage. It looks like it made it through the manufacturers quality control like this. They were both packaged in their own separate boxes and those had no damage.

[JerriAZ]

If I were in your situation, and they were severely dented, I wouldn't use them. In addition to what dynamo said, it's possible that the capacitor will now act as a short circuit if it was crushed to the point where its two internal "plates" are now touching. Do you have a multimeter laying around? Many of them have an option to check for short circuits. Even if there isn't a short circuit though, the capacitor's capacitance would most likely be changed. Hope this helps.

[mzisserson]

Hi Kerry,
You would have to take them out of the circuit to troubleshoot. If your popping them out anyway, you may as well replace them.

I have seen damaged caps from my component troubleshooting days form "hot spots" internally causing a more critical failure later, even if they measure well.

Disclaimer: The "hot spot" formation was explained ro me and shown in the failed cap by a passive component design engineer at Vishay. It was amazing to see what goes into the deaign and operation of something as simple as a cap or resistor.

Any pics?

[Millstonemike]

Get replacements from PE,(free or relatively cheap) and replace them. They can't be in spec. And I agree with Jerri's call that they may be a short circuit (and may blow other parts). In any postulation as to the condition of the caps, it's a bad situation.

IMO, definitely replace them before using the amp.

Edit: Oddly enough here's a bullet point from the amp's page: "Very rugged construction with a 70 G-Shock rating for on the road abuse."

[hongrn]

Kerry,

The caps are polarized, as dynamo said. They're from Elna, so pretty good quality stuff. The values and voltages are printed right on the caps, so sourcing them shouldn't be difficult:

http://www.digikey.com/product-search/en/capacitors/aluminum-capacitors/131081?k=&pkeyword=&v=604&pv405=1607&FV=fff40002%2Cfff80009&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25

Hong

[kenrhodes]

I got you covered send them my way. Send me a P.M. I'll send you my address.

[Psycoacoustics]

Caps with the leads on one end are called "Radial leaded". Caps with one lead on each end are "Axial".

Mark

[Navy Guy]

I'm way outside of the return period, so I won't be contacting PE about helping me out on this one, unless it's to buy caps. What you guys are suggesting is pretty much what I figured... caps need to be replaced.

[dynamo]

As suggested by Hong, you can probably get exact replacements at digikey or mouser. That would be your best bet, since the oe ones are higher quality than ones stocked by pe in this case (sorry pe, no offense)

[Psycoacoustics]

Partsconnexion is a good place to find Elna's. I didn't have much luck with Mouser or Digikey for them.

Good luck, Mark

[dynamo]

Partsconnexion is a good place to find Elna's. I didn't have much luck with Mouser or Digikey for them.

Good luck, Mark

Good to know, thanks. I had gotten some Elna silmic ii caps from one of the two, mouser I think, but didn't look beyond that for elnas.