A rare PolyMoog Synthesiser 203 from around 1977.

I ran out of time, and this is the state of it as of 02/03/24.  I've done an incredible amount of work, so you don't have to!

PSU checked, repaired and calibrated - OK

P6KE16A TVS shorted, taking down the  -15V rail, replaced.

TOS Left (squarewave) a completely shorted 2.2uF capacitor had burned the board and taken out a 7426, 7413, and 7473, all now socketed and replaced.  Plus a 2.2K resistor.  Thankfully the 50240 frequency divider survived.  The board is now clean and working.

TOS Right (sawtooth) OK.  It was fine.

All the dividers now work on both square and sawtooth waveforms.  Five MM5823 ICs were socketed and replaced.

Polycom boards - 13 ICs socketed and replaced.

Polycom boards - 5(!) missing boards fitted.
Balance boards - 2 missing Polycom ICs fitted.
All Polycom and Balance boards are now present and fully operational.

uA726 devices checked and both OK.

TL Main Oscillator board now works after changing all nine CA3080s, three LM358s and a 4011.

Two HEF4046 PLL ICs on TL board missing, now fitted with TI devices.  CA3080 ICs and some LM358s replaced.  The TL Oscillator board now works as it should!  Beat note LED operates as it should.

TR board 2N3906 conducting at 300R from collector to emitter, causing cutoff failure.  Replaced, cutoff OK.  Also replaced the related 2N3904.

Inoperable or intermittent front panel buttons removed and cleaned with my own secret process and replaced.  Now all working.

All front panel LEDs replaced, these were a random bunch of original, filed 5mm, hacksawed rectangular, and 3mm devices, most originals did not work.  What a mess.  They are now in green and look fantastic.

Summary:

7426 *6

7413 *4

7473 *1

7474 *1

7475 *1

4046 *2

4016 *2

4066 *1

4051 *3

4011 *1

4007 *12

CA3080 *9

LM358 *6

Polycom IC *19

MM5823 *5

2.2uF *1

2.2K 0.25W *1

2N3906 *1

2N3904 *1

P6KE16A Transient Voltage Suppressor *1

LED, 3mm *37

PSU now OK

All 37 LEDs now OK

All front panel buttons now OK

TL main oscillator board now OK

TM filter board now OK

TR mixer board still has faults.

TOS generators now OK

24 MM5823 dividers now OK

71 Polycom cards now OK

3 Balance cards now OK

It has been fully powered, no output due to the TR board still having op-amp faults.  Just the TR board to finish off next.  The VCF, LFO and other controls can be heard in the background when keys are pressed, all 71 keys effect this, so all 71 keys work.

All repaired boards and modules have been tested within another fully working Polymoog 203a.

All dead parts supplied on request.

It is clean, all knobs buttons and switches are present.  The numbers have been worn from the selecter buttons from studio use.  The stand castings are included, however there are no screw-in feet.  Unusually, there is no 'MOOG' decal to the rear of the case, nor any sign there ever was one.  The keyboard has some suspicious tiny 'burn marks'.

Of course, you are welcome to open the casing to check everything's in place.

Don't be afraid to ask absolutely anything about it, or to make an offer. 

The full service and operation manuals will be included on disk, no other accessories are included.

Collection is essential and payment made in cash on collection.  You are welcome to take as long as you need to check it to ensure it's exactly as described.  I will not consider shipping it - it will arrive smashed.

All items are USED and will show signs of USE.  All items are photographed inside and out.  All items are SECURITY MARKED and have a non-removable barcoded security sticker to prevent tampering.  It will not be possible to remove or replace internal components without destroying the security measures.