Nichicon - No series identification

[ghiotom]

I have some Nichicon 10 uF 16 V 105° caps out of a Bose sound system with no series markings just A427 which I assume is a date code? Don't know if they were specially built for Bose or they are just general purpose caps. They are in the secondary of a SMPS. I'm guessing a low ESR cap would be the proper replacement?

[stj]

Re: Nichicon - No series identification

Linear regulators - you could use anything there.
10uf 50v panasonic FR or even 10uf 35v tantalums would work

[eccerr0r]

Re: Nichicon - No series identification

Most curious design here.

Agree with the analysis that these are linear and do not require low ESR caps, this does appear to be part of a SMPS of some sort and there should be larger input side filtering that I don't see, or this is really low current circuitry that might be wasting more power or $$ by using SMPS here...? Maybe because I'm just not seeing the whole schematic...

[ghiotom]

Re: Nichicon - No series identification

Here's the full schematic. Those two capacitors highlighted in the first post had ESR 0f 8.6-8.8 ohms each. The two Mosfets (Q101, Q102) had blown and after replacing them along with the controller(U101), several resistors (R101-R104), and Mosfet Q103, I got it working. That lasted about 3 months before they blew again. Just trying to figure out what's happening to the Mosfets.