TRS-80 Fireworks

Kevin Parker trash80 at
Wed Aug 28 17:50:31 CDT 2019

Quite normal - the capacitors dry out after about 30 or  40 years - there's lots of info around on replacing them with a polymer capacitor. I have over 20 TRS-80's with a large contingent of Model 3, 4, 4Ps, 12 and 16s - all had the same issue so if I acquire one now I do a pre-emptive strike before powering up.

Kevin Parker
0418 815 527

-----Original Message-----
From: cctalk <cctalk-bounces at> On Behalf Of Marvin Johnston via cctalk
Sent: Wednesday, 28 August 2019 6:16 PM
To: ClassicCmp <cctalk at>
Subject: TRS-80 Fireworks

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.

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