TRS-80 Fireworks

Marvin Johnston marvin at
Wed Aug 28 09:10:33 CDT 2019

Almost all of my Model 100s (around 8 or so) need to have all of the 
electrolytics replaced. For some reason, they started leaking and 
causing a problem with desoldering the bad parts. Upon close 
examination, the leaking caps can be detected relatively easily. Some 
information I saw somewhere indicated that the Chinese caps are the 
worst offenders... they stole the formula but apparently "modified" it 
slightly ending up with future problems.

Some of this information falls into the "I don't know what I don't know" 
catagory. Nice having the tremendous volume of knowledge here to help out!


On 8/28/2019 6:59 AM, Peter Cetinski wrote:
>> On Aug 28, 2019, at 9:34 AM, Marvin Johnston via cctalk <cctalk at> wrote:
>> Thanks everyone for the feedback... I had no idea. I'll be putting in an order today with Digi-key (P/N 399-7483-ND) for probably around 25+ caps or so since I have at least that many TRS-80 2s, 3s, 4s.
>> I guess my only question is are there other similar caps that also need to be replaced? I'm well aware of the electrolytics and have that project on the back burner right now (about 10 Model 100s to repair.) It is nice that they are pretty trivial to replace!
>> Marvin
> I’ve had very few problems with electrolytics in the many TRS-80s I’ve worked on.  It seems to be one of the places where Tandy did not cheap out.  There are some tantalum capacitors to be found in TRS-80s.  These have a tendency to fail to short so I am wary of them but still, I would probably not replace any unless they failed.

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