HP 7475A Plotter
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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
| 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) |
| RefDes | Qty | Part Number/Model Number | Manufacturer (If Applicable) | Explanation | Datasheet |
|---|---|---|---|---|---|
| U2, U8 | 2 | SN75447P | Texas Instruments | Dual Peripheral Driver | SN75447 |
| U5 | 1 | 8343MDC | AMI | ||
| U6 | 1 | 8323MAL | AMI | ||
| U7 | 1 | SP8344+ | National Semiconductor | ||
| U9 | 1826-0138 | Motorola | |||
| U10 | 2 | MC3447P | Motorola | Bidirectional Bus Transciever | MC3447 |
| U12 | 1 | 1820-2219 | Motorola | ||
| U13 | 1 | 1820-2099 | Motorola | ||
| U14 | 1 | AM9265BPC | AMD | ||
| U15 | 1 | CN65004N | Signetics | ||
| U17 | 1 | SN74LS174N | Texas Instruments | Hex/Quad D-Type Flip-Flops | SN74LS174 |
| U18 | 1 | 1820-2274 | Motorola | ||
| U19 | 1 | 1820-1438 | Motorola | ||
| U21 | 1 | SN74LS04N | Texas Instruments | Hex Inverter | SN74LS04 |
| U22 | 1 | 74LS10N | Signetics | Triple 3-Input Positive-NAND Gates | SN74LS10 |
| Q9 | 1 | 2N3791 | Motorola | PNP High-Power Transistor | SN3791 |
Replacement Parts
Main Logic Board
| 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 / 50YXF22MEFCTA5X11 | DigiKey Mouser LCSC |
| C31, C32 | 2 | 860160674016 / 50YXF47MEFCT16.3X11 | Digikey Mouser LCSC |
| RefDes | Qty | Compatible Part Number | Order Links |
|---|---|---|---|
| U17 | 1 | SN74LS174N / SN74LS174N(LX) | DigiKey Mouser LCSC |
| U21 | 1 | SN74LS04N / SN74LS04N(XBLW) | DigiKey Mouser LCSC |
| U22 | 1 | SN74LS10N / SN74LS10N(XBLW) | DigiKey Mouser LCSC |
| Q9 | 1 | 2N3792 PBFREE / 2N3791 | 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