Commodore 64 s/n U.K.B1697889 Repair Log

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) 🙂

 

Purchased 8th August 2017 on eBay:

  • Breadbin: SER.NO.U.K.B1697889
  • PSU: Part no. 251 053-11
  • Datasette: C2N, Serial No 01202217, Made in Taiwan
  • Motherboard: S/N UA196145, assy No. 250407, artwork no. 251137, rev. B. Made in Hong Kong

 

Chips:

  • U1: CIA, MOS 6526, week 39, 1984
  • U2: CIA, MOS 6526, week 39, 1984
  • U3: BASIC ROM, MOS 901226-01, week 28, 1984
  • U4: Kernal ROM, MOS 901227-03, week 36, 1984
  • U5: Character ROM, MOS 901225-01, (no week/year)
  • U6: Color RAM, MM2114N, week 32, 1984
  • U7: CPU, MOS 6510, week 27, 1984
  • U17: PLA, MOS 906114-01, week 35, 1984
  • U18: SID, MOS 6581, week 34, 1984. Defective – replaced with 6581R4AR, week 14, 1990
  • U19, VIC2, MOS 6569R3, week 39, 1984
  • RAM, 7*OKI M3764-20, 1*Sharp LH2164-15

 

Sellers description:

Commodore 64 Computer C64 Breadbin With Power & Datasette Faulty Spares & Repairs BUY NOW.
Greet Computer found in job lot of items and will sadly not power on ?
Maybe easy fix for someone or at least loads of spares. Comes with power pack and datasette only.

 

Repair log:

  • 9v, 1.5A fuse in PSU blown, changed
  • SID defective, black screen. Works w/o sound when removed. Replaced with spare
  • PSU 5v rail rebuild for future proofing:
    7805 voltage regulator, original electrolytic capacitor and a few other passive components  replaced with 3A buck converter with 4700uF 25v electrolytic capacitor on input. Patched in after diode rectifier.
  • Re-capped motherboard
  • Future proofed the larger MOS chips which heat sinks
  • Cleaned and lubricated datasette
  • Re-capped datasette
  • Fixed ticking noice from datasette when fast forwarding with a piece of heat shrink tube (se picture)
  • Changed both drive belts in datasette
  • Over-voltage protection of 5v PSU-rail on motherboard (installed P6KE6.8CA)

 

Costs (total DKK 875):

  • Breadbin, PSU and datasette: DKK 525.-
  • SID: DKK 250,-
  • Misc.: DKK 100,-

Let me know if you will buy or swap with this unit 🙂

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