23 Jan
2016
23 Jan
'16
8:13 a.m.
On 01/22/2016 06:26 PM, Tothwolf wrote:
The translucent yellow Rifa (now owned by Kemet) class
X/Y safety
capacitors in particular have a 100% failure rate and are on my
replace-on-sight list. They usually begin to show visible signs of cracking
in their outer casing before they finally go out with a bang.
It's a well-known fault, but has anyone ever known one fail and actually
cause any damage (other than to itself)? AIUI, they're there to reduce
noise from the device leaking back out onto the AC supply - a system should
run quite happily without them.
I've had maybe four or five fail on me over the years, out of several
hundred systems. They're a definite weak spot, but given that I've never
heard of one damaging anything it's the sort of thing I'd consider doing
only if I was carrying out some other repair work on the PSU.
I usually replace them with a film capacitor from
Epcos of the same
value and safety class.
Is the voltage rating on the US ones different (new vs. old)? I can't
remember now. I know all the old UK ones seemed to be 250V, while modern
parts were rated at 275V.
cheers
Jules