Commodore 64 s/n U.K.B1717794 Repair Log (Work In Progress)

Do you have a defective / non working Commodore 64 breadbin?
I probably want it!
Make me an offer on gert@dabbler.dk and state if you want to sell it or swap it for this working one (you will have to pay my costs in parts and shipping – but not my time) šŸ™‚

 

Purchased 22th August 2017 on eBay:

  • Breadbin: SER.NO.U.K.B1717794
  • Motherboard: S/N 938896, assy No. 250407, artwork no. 251137, rev. B. Made in Hong Kong

 

Chips:

  • U1: CIA, MOS 6526, week 25, 1984
  • U2: CIA, MOS 6526, week 19, 1984
  • U3: BASIC ROM, MOS 901226-01, week 25, 1984
  • U4: Kernal ROM, MOS 901227-03, week 24, 1984
  • U5: Character ROM, MOS 901225-01 (no week and year)
  • U6: Color RAM, MM2114NĀ (no week and year)
  • U7: CPU, MOS 6510, week 29, 1984
  • U17: PLA, MOS 906114-01, week 22, 1984
  • U18: SID, MOS 6581, week 25, 1984
  • U19, VIC2, MOS 6569R2, week 25, 1984
  • RAM, 8*Mitsubishi Electric M5K4164ANP

 

Sellers description:

Commodore 64 keyboard.
No other items with this.
I have confirmed the power light lights up when plugging my power pack in.
2 loose buttons, included. Can be glued back on.

 

Repair log:

  • 4 loose buttons (F1, +, C= and Run/Stop). Replaced plundgers
  • Plastic screw holes for motherboard damaged. Repaired/recreated/strengthened with hot glue
  • Cabinet screw holes damaged. Repaired/recreated with hot glue
  • F7/F8 not working – broken trace on keyboard PCB repaired
  • U25 (MOS7708, week 23, 1984) defective. Black screen but with video sync. Replaced with HD74LS257P. Board hard do desolder on because of corrosion, so damaged 3 tracks. Those repaired with wires.

 

Work in progress:

  • 1 wobling button (V). Glue half broken plundger if possible – otherwise replace
  • Cleaning
  • re-capping motherboard/RF-module
  • Heatsinking larger MOS chips
  • Overvoltage protection on motherboard (P6KE6.8CA)
  • Build a PSU

 

Costs (total DKK 800):

  • Breadbin: DKK 400,-
  • Plundgers: DKK 75,-
  • PSU (transformator, wire, connector): DKK 225,-
  • Misc.: DKK 100,-

Let me know if you will buy it for my costs when it is done šŸ™‚

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