[Coco] Re: Let me introduce myself (GW/CoCo BASIC similarities)
Richard E. Crislip
rcrislip at neo.rr.com
Mon Feb 6 04:18:33 EST 2006
On 02/05/2006, Gene Heskett wrote:
> On Sunday 05 February 2006 04:47, Richard E. Crislip wrote:
>>Thanks for the reply, I am not sure what those caps are that you are
>>refering to, but I would guess that that would be my next step. I have
>>already removed and cleaned all the socketed parts (including the
>>daughterboard. No joy. So the caps seem like the next target. Could I
>>purchase them, cut the old ones off and solder the replacements on to
>> the place of the old ones? I'm not good enough and do not have the
>> equipment to desolder surface mounted components.
> No, that will take a soldering iron that looks like an overgrown set of
> tweezers so it can hit both tabs of the cap at the same time.
> The only one I'm fam with is a GC thing, and needs a powerstat to turn
> it down, it gets way too hot after 5 minutes at full voltage. Even
> turned down, it can get the caps hot enough to explode them. No real
> damage though other than to ones nerves :)
> Since measureing those is a pita in circuit, investigate a gizmo called
> a capacitor wizard. Its a bit pricey at about $175, but it measures
> the caps ESR at 100 kilohertz, the most important cap characteristic
> for digital circuitry. Anything over 1 ohm is suspect. You absolutely
> need one of those if you do service for a living.
> Also, if there is a commie 040 card in it, be aware that whoever made
> that for commie put all those caps on it bass ackwards, so the failure
> rate is 100% long before now. They usually fail open, with now dried
> leakage products all over the board under them, and which is somewhat
> corrosive... Gets into the board and eats inner traces in two where
> you can't fix it, or shorts layers too. And its crowded, very hard to
> get the iron in there to replace them. After about 5 of them on that
> board I'm ready to shoot the neighbors cat or something. It has IIRC
> 14 of them.
> Absolutely the most piss-poor assembly Ijob 've seen in my 55+ years of
> holding an iron in one hand.
> The german made 060 card is a far better card.
I have the german 060 card so that may be not a problem. I know this is an
off topic subject for this M/L but is there a site I can go to that would
have grapics to point those umbrys out?
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With an Amiga ---o-o-O-o-o--- and a CoCo
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