Tag: Repair Log

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

Commodore logo

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 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, MM2114N (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 🙂

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Commodore 64 s/n U.K.B1309074 Repair Log (Work In Progress)

Commodore logo

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 18th August 2017 on eBay:

  • Breadbin: SER.NO.U.K.B1309074
  • PSU: Part No. 310200-04
  • Datasette: C2N, Serial No 2871008, Made in Taiwan
  • Joystick: Spectravideo, model 318-102
  • Original Commodore 64 MicroComputer User Manual, 1984, Printed in England
  • The Commodore 64 Games Book – 21 Sensational Games by Oweb Bishop, 1983, Printed in Great Britain
  • Motherboard: S/N 057894, assy No. 250425, Made in Hong Kong

 

Chips:

  • U1: CIA, MOS 6526, week 31, 1984
  • U2: CIA, MOS 6526, week 31, 1984
  • U3: BASIC ROM, MOS 901226-01, week 28, 1984
  • U4: Kernal ROM, MOS 901227-03, 1983 (no week)
  • U5: Character ROM, MOS 901225-01, week 33, 1984
  • U6: Color RAM, MM2114N, week 24, 1984
  • U7: CPU, MOS 6510, week 31, 1984
  • U17: PLA, MOS 906114-01, week 27, 1984
  • U18: SID, MOS 6581, week 28, 1984
  • U19, VIC2, MOS 6569R2, week 35, 1984. Defective replaced by TDB
  • U31, MOS 8701, week 34, 1984. Defective replaced by TDB
  • RAM, 8*NEC D4164-2

 

Sellers description:

Good Commodore 64 personal computer, tape player, 1 joystick, leads + power pack.
The power pack overheated at one stage but still worked – hence the tape around it.
I have not tested to see if the power pack will still work but I would say it was much safer to use an alternative power pack!
The Commodore has not recently been tested but was working when last used and has been well looked after so I do not see there would be any problems with it.
No original packaging.

 

Repair log:

  • Black screen of Death. No clock on MOS 8701. Replaced
  • Grey screen of Death (blue border). VIC2 defective. Replaced.
  • Glued datasette connector (broken plastic). Ground wire torn – hidden in connector (rarely used anyway).
  • Trashed PSU as it is non-repairable (covered in un-removable epoxy). Salvaged wire/connector for Commodore 64
  • Re-capped motherboard
  • Cleaned and lubricated datasette
  • Changed both drive belts in datasette

 

Work in progress:

  • Heatsinking larger MOS chips
  • Put week+year of new 8701 and VIC2 in here 🙂
  • Overvoltage protection on motherboard (P6KE6.8CA)
  • Re-capping datasette
  • Build new PSU
  • Clean/test joystick

 

Costs (total DKK 1.000):

  • Breadbin, joystick, books and datasette: DKK 500.-
  • MOS 8701: DKK 100,-
  • VIC2: DKK 175,-
  • PSU (transformator): DKK 125,-
  • Misc.: DKK 100,-

Let me know if you will buy it for my costs when it is done 🙂

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

Commodore logo

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 🙂