28 Aug
2019
28 Aug
'19
2:05 a.m.
Matt wrote:
On 28/08/2019 09:15, Marvin Johnston via cctalk
wrote:
I've had several instances of it with BBC Micros, also containing Astec brand
power supplies. Typically, when switched on after a long period of idleness,
the machine works fine for minutes to hours, then there is a quiet pop followed
by a whoosing noise and smoke starts pouring of the mains filter capacitor
while the machine continues to work away quite happily.
Regards
Peter Coghlan.
I'm just curious how many people have powered
up their TRS-80
computers, and ended up with a bang and a room filled with smoke?
So far, I've gotten the fireworks in two out of two TRS-80s (model 3
and 4) when they were powered up. In both cases, the problem was with
the main line filter capacitor mounted on one of the power supplies.
The computers continued to work which was my first clue the problem
was not serious :).
Is this a normal problem with these older computers? I'm used to
seeing the electrolytics give problems, but this is the first time
I've seen one of the X type line filter caps blow.
This is very common for these paper line filters. I've had the same
failure with an Osborne 1, DECserver 200, DELNI and PDP-11/73. There are
many more devices that have them; generally anything with an Astec brand
power supply. I replace them before even powering up these days.