Sinclair ZX spectrum 48K
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- For more information, see this article's corresponding Wikipedia page: https://en.wikipedia.org/wiki/ZX_Spectrum.
Sinclair ZX spectrum 48K
| Preliminary Information | |
|---|---|
| Release Year | Introduced 1982 Discontinued 1992 |
| Mounting Technology | Through Hole and Sockets |
| Capacitor Types | Aluminum Electrolytic |
| Destructive Entry | No |
| Hardware Specifications | |
| CPU | Zilog Z80A 3.5Mhz |
| Memory Capacity | 48K |
| Memory Type | 4116 DIP |
| Storage | Cassette recorder. |
| Display Interface | RF analogue (PAL) |
| Sound | Piezo speaker |
| Power Requirements | |
| Input Voltage | 9V DC |
| Current (Amps) | 1.4A |
Known Issues
Symptom or Problem Encountered
Causes
- Keyboard non functional
Solutions
- Replaced decayed keyboard membrane
Disassembly Notes
Opening the case
Firstly undo the 5 Philips head screws on the bottom then carefully lift the top case off while mindful of the keyboard ribbons as these can easily get torn.
Removing the keyboard membrane
- To remove the old keyboard membrane after you have removed the top part of the case use a heat gun on the lowest setting to loosen up the adhesive under the metal plate to help prevent damage to the metal cover.
- After removing the metal plate lift the rubber key mat off the shell and then slide the old membrane out.
- To reassemble follow the steps in reverse and reattach the metal plate with new double sided tape.
Original Parts
Mainboard
This is the list for a issue two 48K PCB
| RefDes | Qty | Capacitance | Voltage | Mount | Diameter/Size | Height | Lead Spacing | Temp | Type | Brand | Series |
|---|---|---|---|---|---|---|---|---|---|---|---|
| C25, C28, C34, C47, C50 | 5 | 22µF | 10v | Axial | 0 °C | Aluminium electrolytic | |||||
| C46, C27 | 2 | 1µF | 50v | Axial | Aluminium electrolytic | ||||||
| C44, C45 | 2 | 100µF | 16v | Axial | Aluminium electrolytic |
This is the list for a issue 6A 48K PCB
| RefDes | Qty | Capacitance | Voltage | Mount | Diameter/Size | Height | Lead Spacing | Temp | Type | Brand | Series |
|---|---|---|---|---|---|---|---|---|---|---|---|
| C25, C28, C34, C50, C65, C80 | 6 | 22µF | 10v | Axial | Aluminium electrolytic | ||||||
| C74 | 1 | 4.7µF | 6v | Axial | Aluminium electrolytic | ||||||
| C27, C46, C79 | 3 | 1.0µF | 50v | Axial | aluminium electrolytic |
Replacement Parts
Mainboard
Issue two 48K
| RefDes | Qty | Compatible Part Number | Order Links |
|---|---|---|---|
| C25, C28, C34, C47, C50 | 5 | 226TTA035M | DigiKey Mouser |
| C46, C27 | 2 | 105TTA050M | DigiKey Mouser |
| C44, C45 | 2 | 107TTA025M | DigiKey Mouser |
Issue 6A 48K
| RefDes | Qty | Compatible Part Number | Order Links |
|---|---|---|---|
| C25, C28, C34, C50, C65, C80 | 6 | 226TTA035M | DigiKey Mouser |
| C74 | 1 | 475TTA050M | DigiKey Mouser |
| C27, C46, C79 | 3 | 105TTA050M | 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.
Kits
- Digikey BOM: https://www.digikey.com/