JohnW
pfm member
Styrenes would probably not live long in the very hot class A environment of MDAC/FDAC.
The PCB does not get hot enough to cause problems with Styrenes - they dont dry up - in fact they work better with any internal moisture dried out...
Maybe the heat is also the problem with those bulging caps.
The problem is not heat related I have "New" old boards that have never been powered and the caps have failed - theres some internal chemical reaction going on.
Its mos often the 470/6.3V parts that fail - 80% of the time the other values near the hot heatsinks are OK.
There is no heat on the PSU PCB yet these caps pop.
It's just not "normal" to see so many bulging caps inside hifi devices, or is it?
No its not normal, my best guess is that the problem is the capacitor vendor has messed up the Chemical formulation of the Electrolyte...