[sdiy] How I spent my week (Polymoog restoration-long)

[Roy J. Tellason]

On Saturday 19 March 2005 06:37 am, Kevin Lightner wrote:

<...>

> Keep in mind- I've yet to open the schematics or power it up!

Heh.  Your client must have some fairly deep pockets...

> There's no use testing a synth that has obvious visual problems and
> can cause worse damage, imho.
> All CMOS IC's, previously in sockets (except 4046's) were tested on
> an IC tester and several were bad and replaced. What's left, I will
> soon discover.

What IC tester are you using there?

> This unit has been to four, count 'em, four LA techs.
> Each one took a stab at it and failed.

It amazes me how many people are calling themselves "techs" and how much that 
word gets mis-applied these days.  In the sunday classifieds I see places 
looking for "nail techs" (as in fingernails)...!

<...>

> Several of the dividers were replaced with a cmos based pcb (you've
> probably seen this mod offered online before).

Nope.  Got a URL handy?

> The owner said he wants it as nice as possible and that costs are not
> an issue, but time is. With that in mind..... ;-)

Woohoo!  :-)

> All jack hardware replaced
> Jacks cleaned/polished
> S-trig jack replaced

It having been a LONG time since I've seen one of those (and I don't have the 
service data handy at present),  is that the same connector that Moog used on 
other stuff?  What do you call those,  anyhow?

<...>

> Repainted silver lettering/legends, etc.

That's definitely further than I'd go.

> Cleaned all sliders, switches and connectors
> Cleaned and resurfaced ribbon controller to new condition

I always did like that ribbon controller.  How did you fix that?

<...>

> Board washed

In what?

<...>

> IC sockets eliminated

I notice you mention this a lot -- why do that?  Have the sockets in those 
proven to be that unreliable?  Sure sounds like a lot of work.

<...>

> Replaced transformer connections with new, gold plated mating connectors

It's been quite some time since I saw one of these and I have no recollection 
of what they used for transformer connections.  I do recall running into 
problems in other gear where they used a molex-type connector with *round* 
pins on the board and wiping contacts in the connector shell,  which would 
overheat,  oxidize,  and eventually cause all sorts of problems.  (This was 
in the Heath-Zenith H89/90 computers,  and similar terminals,  if anybody's 
curious.)  The fix there was to change out the round pins for square ones.  I 
don't think I've ever seen gold plated connectors for this application,  
though

> Replaced 25 year old, single turn adjustment trimmers with new, 25
> turn cermet trimmers

That's a mod I've wanted to try for a long time for a minimoog,  never did get 
around to it,  though.

<...>

> 14 keys replaced (special weighted types)

Those are the ones with a bit of birdshot in epoxy,  right?

> All solder used is Kester silver bearing solder

Why?

> Unit will be tested, any component level troubleshooting completed
> and calibrated next week.
>
> Cost? I have no idea.
> What would YOU charge?? :)

What's your time worth?

I was at the Moog factory to learn about those things back in,  oh,  1977!  
(Jeez!)  Saw a number of them after that,  but I don't think I've seen one 
since I left the NYC area back at the beginning of 1978.  Think there's many 
of them out there still?