[Coco] CoCo in France

Neil Cherry ncherry at linuxha.com
Sun Feb 10 12:42:39 EST 2019

On 2/10/19 12:20 PM, Gene Heskett wrote:

> I'll make a SWAG here after putting on my CET hat, and say the big
> electrolytic capacitor on the mainboard, not too far from the bigger
> transistor on a heat sink of sorts was getting pretty well dried out,
> and while it could hold a usable voltage during the low voltage portion
> in a 60 hz wall supply, but is falling short on the longer low voltage
> period of a 50 cycle supply. We tend to forget that these things are 30+
> years old, and the average life of such is not measured in multiple
> decades.
> Not to mention that the power transformer in the coco was a 60 hz rated
> one, and is going to run 15 or so degrees F warmer on 50 hz, due to the
> longer time the primary current has to build up, approaching the
> saturation point of its iron core.
> So at a minimum, that cap might need replaced.
> If the iron does saturate magnetically the current flow in the primary
> will rise to resistive limits and will likely toast the transformer at
> some point, compared to the 100+ years it will run on 60 hz. But IIRC
> there's a fuse on that little pcb which might interrupt that.  If it
> clears, the coco will be completely dead. I've only seen one of those
> fuses fail, so its not a common occurrence on 60 hz power.
> That capacitor, IIRC is a 4700 uf, and on 50 hz power, a 6800 uf would be
> a better replacement.

+1, what he (Gene) said ... :-)

Linux Home Automation         Neil Cherry       ncherry at linuxha.com
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Author of:    	Linux Smart Homes For Dummies

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