HP 7475A Plotter

HP 7475A Plotter

Preliminary Information
Leak Risk	Medium
Batteries	None
Mounting Technology	Through Hole
Capacitor Types	Aluminum Electrolytic, Tantalum, Ceramic
Destructive Entry	No

HP plotter with HP-IB (GP-IB) interface. Hold 6 pens in carousel.

Known Issues

Fish Smell

Causes

• Leaking capacitor

• 

  Leaking cap visible on logic board with electrolyte seeping up the jacket

• 

  Sprague brand capacitor that has leaked and formed a powder moving up into the jacket of the capacitor.

Solutions

• Clean PCB and replace cap

Disassembly Notes

Screws in rear from top removes plastic shell.

Two screws going through plot mechanism and PCB hold both in. HP-IB port screws must also be removed to remove PCB.

Original Parts

Main logic board

07475-60102

Capacitor Specifications and Footprint Information

RefDes	Qty	Capacitance	Voltage	Mount	Diameter/Size	Height	Lead Spacing	Temp	Type	Brand	Series
C1	1	68 µF	35V	Through Hole	10mm	20mm	5mm	-55-105 °C	Aluminum Electrolytic	Nippon Chemi-Con	CERX
C2	1	2,200 µF	40V	Through Hole (3 pin)	25mm	67mm	9.5mm		Aluminum Electrolytic	Sprague	674D
C24	1	6,800 µF	25V	Through Hole (3 pin)	25mm	39mm	12mm	85°C	Aluminum Electrolytic	Nippon Chemi-Con	SM
C20, C25	2	22 µF	25V	Through Hole Axial	6mm	13mm	20mm	85°C	Aluminum Electrolytic	Nichicon	H8333 ?
C31, C32	2	47 µF	50V	Through Hole	8mm	12mm	3.5mm	85°C	Aluminum Electrolytic	Nichicon	SE (M)

Replacement Parts

Main Logic Board

Capacitors

RefDes	Qty	Compatible Part Number	Order Links
C1	1	EEU-FR1V680B	Digikey Mouser
C2	1	UPM1H222MHD	Digikey Mouser
C20, C25	2	500D226M025BA2A	Digikey Mouser
C24	1	25PK6800MEFC16X31.5	DigiKey Mouser
C31, C32	2	860160674016	Digikey Mouser

If parts are not available or different selection is preferred, you can use the values in the Original Parts section to perform a parametric search