Re: Major Havoc pincushion question

It definitely reminds me of my Star Wars (has a 6100) before I installed
your correction board.

I've now checked all the resistors and they seem fine. I also went
through and checked for broken traces. For fun, I went ahead and
replaced the two electrolytic caps and all eight little 0.1 caps as well
as the 7815 and 7915. I also carefully desoldered the 1495's, installed
sockets, and a new pair of 1495's. After all that, the amount of
pincushioning is still the same. I have +6.8 and -15 volts at the
1495's, but forgot to check the +15.

Does anyone have a copy of the schematic for the Major Havoc to Space
Duel adapter board? All I can find is the one for Tempest, and all the
component labels are different.

Anybody out there have a Major Havoc conversion who can tell me if they
have more or less pincushioning than I do?

Thanks,

Alan

Clay Cowgill wrote:
>> Is this amount of pincushioning normal for this situation?
>> (Major Havoc conversion pcb with Space Duel adapter pcb and WG K6100)
>
> Doesn't look right to me-- that might even look worse than no correction at
> all! ;-)
>
> I would be suspicious of the correction board operation. Check for any
> cracked resistors around the 1495's (from rough handling or something).
> There's a couple resistors that essentially set the correction 'level' and a
> problem there could lead to 'no correction' on the output signal. (I used a
> potentiometer on my display corrector for that part of the transform, but
> the original boards have a pair of fixed resistors.)

-- 
Total Impulse - Just Having Fun!
Alan Estenson, totalimpulse@comcast.net
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