Re: Electrolytic Caps in CBM equipment

On 2/5/20 8:17 PM, silverdr_at_wfmh.org.pl wrote:
> 
> 
>> On 2012-09-08, at 15:45, Gerrit Heitsch <gerrit_at_laosinh.s.bawue.de> wrote:
>>
>>> These were all made by a company called Bellcon which I'd not come
>>> across before. Has anyone else had any other issues with consistently
>>> problematic caps in CBM equipment, either by manufacturer or in specific
>>> hardware?
>>
>> I don't remember the maker... But not long ago I had a C64 KU-board (*) for repair here and the problem were 2 rather small electrolytic capacitors in the clock circuit, C107 and C108 (visible on the image below right and left of the 74LS629). Both of them had started leaking and the electrolyte from C107 had eaten through a trace that supplied pin 15 of the 74LS629, resulting in the master oscillator not working.
> 
> Seems to be more than common. After having a stab at fixing another KU (yeah, for testing...) these few years later it has eaten several traces around the LS629 pads and even the pins, partially. And it's not the first one that exhibited similar damage. So if you (CBM hacker) have a nice, working KU board, where the caps were not replaced in time, do it now…

They were not only used there. If you have an SFD-1001 or a 8250LP, you 
will have leaky caps on the motor controller board of the drive 
mechanics. Over time they will damage the traces.

This was posted before, but it can't hurt to post it again as a reminder.

  Gerrit