[Coco] CoCo repair-upgrade

Chad H chadbh74 at hotmail.com
Mon Sep 26 00:19:03 EDT 2011


Quiet possible.  I was actually concerned of creating cold solder joints
myself by mistake.  Before trying to solder these boards, the only soldering
I had ever done was low gauge (<14) wiring on high heat (40 watt) with flux.
I dropped to 15w for soldering the sockets and relied solely upon the flux
in the solder core.  Apparently it was more than sufficient though.  It took
right to the parts.

-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On
Behalf Of Arthur Flexser
Sent: Sunday, September 25, 2011 11:03 PM
To: CoCoList for Color Computer Enthusiasts
Subject: Re: [Coco] CoCo repair-upgrade

As far as your receiver goes, I think it's a safe bet that you had a
cold solder joint that was fixed by your resoldering.

Art

On Sun, Sep 25, 2011 at 11:46 PM, Chad H <chadbh74 at hotmail.com> wrote:
> 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
>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco
>

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