25 Apr
2011
25 Apr
'11
10:49 a.m.
On 24 Apr 2011 at 12:04, Ian King wrote:
Err yes :-(. Fortunately many older classic computers don't have stupid
design featuers like that.
Industry studies (work by Cornell Dublier) show
that aluminum
electrolytic capacitors have a limited life span. (The most common
failure mode is not drying out, it is elevated ESR.) Then there have
been the various scandals about substandard components.
I'd also add, at least in the case of consumer devices, crappy
designs leading to operation at elevated temperatures. I can show you units where electrolytics are hot-glued to heat
sinks. Inverters
and power supplies for LCD monitors are some of the worst examples.
And then there's the sealed DC "wall wart" power supply.
I think you all know my views on wall weats. I hate them. I prefer to
make my own PSU in a properly earthed metal case with fuses on mains and
output side. And with the electrolytics put in a sensible place.
Some wall-wrts over here are screwed together, often with non-standard
screws. I have a PSU for one of my machines that was assembled iwth
System Zero screws down deep holes, and is thus impossible to dismantle
non-destructively without the right tool (which you don't find in every
tool shop...). Onee I'd got it open, I found the only problem was a
blown fuse, a normal 20mm cartdirge fuse in clips on the PCB with the
silk-screen indicating the type/rating to use. Very easy fix once I'd got
the screws out.
-tony