iz8dwf | Commodore 1540/1541 Long Board (long!) repair. @iz8dwf | Uploaded January 2020 | Updated October 2024, 1 hour ago.
CBM VIC-1541/1540 "Long Board" electronic repair. This board comes from a viewer, there have been a few repair attempts before. Faults found are: one zener diode broken (maybe overheated?), one interrupted small signal diode, one missing connection from a previous chip substitution and one 74LS07 probably fake (or coming from a discarded/defective batch?).
As always, I tried to explain as much as possible about the repair process and my reasoning during the troubleshooting.
Thumbnail's picture is the actual disk drive this PCB belongs to, its s/n is unreadable.
Commodore VIC-1540:
c64-wiki.com/wiki/Commodore_VIC-1540
zimmers.net/cbmpics/d1540s.html
CBM VIC-1541/1540 "Long Board" electronic repair. This board comes from a viewer, there have been a few repair attempts before. Faults found are: one zener diode broken (maybe overheated?), one interrupted small signal diode, one missing connection from a previous chip substitution and one 74LS07 probably fake (or coming from a discarded/defective batch?).
As always, I tried to explain as much as possible about the repair process and my reasoning during the troubleshooting.
Thumbnail's picture is the actual disk drive this PCB belongs to, its s/n is unreadable.
Commodore VIC-1540:
c64-wiki.com/wiki/Commodore_VIC-1540
zimmers.net/cbmpics/d1540s.html
