Search Posts:

Commodore 2040 Drive Repairs


Return to Threads

  Commodore 2040 Drive Repairs by Bill Degnan - 12/07/2019 11:19
Commodore CBM 2040 Disk Drive
Turned my attention to a dead CBM 2040 drive. Totally dead, no power. First thing I checked was the fuse, but it was ok. Next I checked the voltages coming into the transformer, nothing. Click image for larger view.

Commodore CBM 2040 Disk Drive
Found the problem. The person who serviced this drive whatever years ago attached one of the power switch wires to the outer post of the fuse holder, but did not make sure that there was an actual connection to the fuse itself. Almost looks like a homebrew cigar ring or something. Click image for larger view.

Commodore CBM 2040 Disk Drive
I replaced the entire fuse holder. Not a perfect fit but close enough. Click image for larger view.

Commodore CBM 2040 Disk Drive
Click image for larger view.

Commodore CBM 2040 Disk Drive
After re-assembling the power supply I fired up the drive. Cap C31 blow immediately. Otherwise the drive fired up nicely and initialized. With a bad C31 one can run the drive for a little while but eventually the associated voltage regulator will blow out too. Click image for larger view.

Commodore CBM 2040 Disk Drive
Drive D1 is a little sluggish, needs service. Pictured is what it looks like when the drive and computer don't quite synch their messages. After working with the drive to exercise it, performance improved. Click image for larger view.

NEXT - Fix cap C31, grease/lube the drives. These are Shugart 390's which are more or less 400's if I need parts. Nice thing about the 2040's is that they're easy to work on.



Buy a Commodore Computer Poster

Popular Topics and FAQs

  • Commodore B Series Tips and Tricks
  • Aerocomp TRS 80 M 1 Expansion Unit DDC
  • Items Wanted
  • Lobo Max 80
  • Zenith Z-19-CN
  • Prototype PET 2001 photo
  • Using Toggle Switches to Analyze Memory
  • Commodore Disk Archive Project
  • PET 2001 Prototype at Gametronics 1977
  • Jim Butterfield Photo
  • IMSAI 8080 With Processor Tech. Cutter
  • Secrecy is the keystone of all tyranny
  • Cromemco System Three
  • Northstar Horizon - Boot Problem
  • Computer History and Restoration Links
  • Commodore BX-256-80 - 8088 Co-processor
  • S-100 board testing with Z-80 ICE
  • Donner 3500 - an early portable computer
  • Digital (DEC) PDP 11/05 NC Assembly
  • Univac 1219 rescue
  • Fido BBS listing node list 6-13-1986
  • PDP 8e
  • MITS 88-2 SIO (2SIO) for BASIC
  • Visual Technology Inc Model 1050
  • Amiga 2500 Restoration
  • The Evolution Of IBM Computers
  • Replacement teletype print hammer head
  • Archiving and Copying Software 101
  • Computers Built 1940 - 1950
  • CBM B-520 (a.k.a B256-80 or B500 256)
  • RCA COSMAC Microkit
  • Commodore 64K C-116 Mods
  • MITS 8800b Turnmon 9600 baud
  • Catweasel, 8in and 5 1/4
  • Raspberry Pi as Gateway to Internet
  • Digital PDP11 late 1969 early 1970
  • PDP 11/40 72 inch cabinet model
  • PDP 11/40 Industrial 11 model
  • Digitial MicroVAX 3100 30 System
  • Digital VAX 4000-200
  • Commodore 64 / 1541 DRIVEKNOCK
  • Booting the System Using RL02 drive
  • PACS: Reflections by Kathleen Mauchly
  • Tele-Graphic Computer Systems Inc.
  • Commodore B Series SID Jukebox?
  • Installing Core into PDP 11/40
  • Setting Up OpenVMS 7.1 DNS CLERK
  • Felt-Tarrant Comptometer Model J
  • NextStation Color
  • Digital Rainbow (PC100-B2)
  • 1970 Compusad Compulogical Tutor
  • Archiving Papertapes Using DSI NC 2400
  • 1976 P.C.C. Features the MAI JOLT 6502
  • 1961 Beckman DEXTIR Computer
  • UNIVAC 1 and UNIVAC File Computer 1
  • Past Issues:

    vcfmw ECCC 2010 gizmos sbc6120

    This image was selected at random from the archive. Click image for more photos and files from this set.