[Coco] CoCo repair-upgrade

Chad H chadbh74 at hotmail.com
Sun Sep 25 23:46:38 EDT 2011


Ok a few months ago I had a bad CoCo 2 I had to learn to de-solder the CPU
and solder in socket for new one.  Had such success with it I went ahead and
unsoldered the RAM and soldered in sockets, re-using the existing ram.  Went
ahead and did this to couple more CoCo's and feel relieved at how easy it
was and now all I would ever had to do is replace chips that are socketed if
they go bad.  I even ended up following the notes of a CoCo user about
upgrading the FD-502 packs' 7416 buffer chips to 7406 (Greater voltage spike
tolerance I'm told, 30v vs 15v of 7416).  Again was easy and great
experience.  If anyone has a flaky CoCo or FD-501/502 controller pak they
need repair I would highly recommend taking a crack at this..it wasn't that
bad at all, especially if you've ever soldered anything.  If not, send it to
me, I'd be more than happy to assist.

 

While I'm not confident enough to attempt soldering SMD's(?) or other modern
miniature surface mount ICS's, I feel pretty good about the CoCo components.
I even finally got the nerve up to open up my old Technics audio receiver
that had been showing "overload" seemingly randomly".  Started de-soldering
components I could figure out how to test and then resoldered them.  I
couldn't identify a smoking gun, but oddly enough I haven't seen the
'overload' anymore.weird.

 

I would like comments (hopefully constructive) and suggestions on my work
from anyone that's already experienced with soldering IC's and components.
I've already  taken photos of a FD-502 pak I upgraded and put them in the
link here.  http://www.mediafire.com/?cde2vmcqp63jt   The 26-3127 & 26-3127B
CoCo 2's pictured there were both upgraded as well.  I can disassemble them
and take photos of the work if anyone's interested.  

 

-          Chad




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