Date   : Sat, 25 Jul 2009 15:04:36 +0100
From   : zeem.uk@... (Alex Taylor)
Subject: BBC Model B smoking

2009/7/25  <AlembicPrs@...>:

> Before I power up a third Beeb, can anyone tell me what the poblem is.
> Obviously, some component is failing.

Check out: http://www.sprow.co.uk/bbc/howto.htm#powersupply

The class X2 filter capacitors in positions C1 and C2 often explode
when powered up after long periods of disuse. I've had this happen to
loads of mine, and it's never caused any effect other than the smoke
and burning smell. You'll probably find that the units still work
fine, although the smell can be off-putting when the PSU warms up.

The parts cost less than a quid each from Maplins, and can be fitted
by anyone reasonably handy with a soldering iron. The most fiddly bit
is getting the PSU circuit board out in order to be able to fit them.
The usual caveats apply regarding working with power supplies.

-- 
Alex Taylor