TRS-80 Fireworks

[Marvin Johnston]

The article I found online was:

http://www.akhara.com/trs-80/psrepair/index.html

But the reference you posted gave me some excellent perspective on the 
what is what and why :)!

Marvin


On 8/28/2019 6:50 AM, W2HX wrote:
> Be sure to read this article. The caps used in this capacity (pun intended) are specialized...
> 
> https://www.allaboutcircuits.com/technical-articles/safety-capacitor-class-x-and-class-y-capacitors/
> 
> 
> ________________________________________
> From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Marvin Johnston via cctalk <cctalk at classiccmp.org>
> Sent: Wednesday, August 28, 2019 9:34 AM
> To: Ethan Dicks; General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: TRS-80 Fireworks
> 
> 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
> 
> 
> 
> On 8/28/2019 5:34 AM, Ethan Dicks wrote:
>> On Wed, Aug 28, 2019 at 4:16 AM Marvin Johnston via cctalk
>> <cctalk at classiccmp.org> wrote:
>>> 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?
>>
>> I've had identical experiences with Rifa caps as others here.  One
>> thing about them, you don't need to be powered on.  The caps are
>> usually on the hot side of the power switch.  I've had a MicroPDP-11
>> and a Commodore D9060 sizzle when plugged in but powered off.
>>
>>> 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.
>>
>> Rifa caps are notorious for reasons already described.
>>
>> Found in a lot of 1980s gear, TRS-80, Commodore, DEC... Replace on sight.
>>
>> -ethan
>>
>