Commodore 1541 Floppy Drive Hardware Failure Cheat Sheet

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Commodore Diagnostician II By Ian Perry, Kyneton, Victoria 3444, Australia Sept 1989 Symptomatic Chart Diagnosing Faulty IC Components On Commodore 1541 Floppy Drive	6502	6522	325302	901229	LB311	592	9602	325572
Error LEB blinks on power up	x		x
Searching with no red LED			x	x
Drive fails to read					x	x	x	x
Fails to fomat		x						x
Stepper motor does not step		x						x
Will not save when drive heats up	x	x
Lights stay on, motor runs continuously	x			x
No LEDs on power up	Check power supply voltage, Check CR3, VR2, VR1, CR1
Drive motor runs continuously with no green LED	Check 5Volt on power supply
Flashing light on and off	Check UC1, UD2
Message of ‘FILE NOT FOUND’ is displayed	Check alignment, defective disk
Drive speed will not stabilize	Clean drive head w/ Alcohol, check alignment
Display reads ERROR 21-29 (Disk Errors)	Checl PCB speed (LAG570 – for Newt. Drive)
Write protect on ERROR #25	Check WPS, UA1, Write Protect Switch, alignment
Track 18 Display 21 read ERROR	Check alignment, UC2, UE6, check R/W head
Will not load certain programs	Check alignment, track 0 stop