Apple Macintosh Classic analog board

Analog Board

Repair notes

I bought this compact Macintosh in September 2019 – it’s the second Classic (I) I own.

On the surface everything was looking great, no battery leak, no dust bunnies, no previous “hacks” and no bulging capacitors.

At first boot, there was no response.

Looking at the analogue board, the glass fuse was blown.

I bought new fuses and replaced accordingly.

Upon boot, there was a flash and the new fuse was blown.

I’ve seen this referenced here, and here.

Capacitors

Position(s)	Description	Capacitance	Voltage	Lead Spacing	Diameter	Length
CP2	Aluminium Electrolytic Capacitors – Radial	1000 µF	35 V	5 mm	12 mm	32 mm
CP3, CP12	Aluminium Electrolytic Capacitors – Radial	1000 µF	16 V	5 mm	10 mm	31 mm
CP4, CP9, CP10	Aluminium Electrolytic Capacitors – Radial	470 µF	25 V	5 mm	10 mm	16 mm
CP6, CP36	Aluminium Electrolytic Capacitors – Radial	2200 µF	10 V	5 mm	12 mm	25 mm
CP7	Aluminium Electrolytic Capacitors – Radial	1000 µF	10 V	5 mm	10 mm	22 mm
CP8	Aluminium Electrolytic Capacitors – Radial	2200 µF	16 V	5 mm	12 mm	32 mm

Glass Fuse

Position	Description	Mounting Style	Current Rating	Voltage	Diameter	Length
FP1	Cartridge Glass Fuse – Fast Acting	Holder / Clip	2.5 A	250 VAC	5 mm	20 mm

MOSFET

Position	Description	Mounting Style	Reference (original)
QP2	MOSFET	Through Hole	IRFBC40 9052 5T 9R

Optocoupler

Position	Description	Mounting Style	Reference (original)
QP1	Transistor Output Optocouplers	Through Hole	PHILIPS CNY17G-3 m9046