Amstrad PC3386SX Maintenance Guide
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The Amstrad PC3386SX uses the Amstrad PC3286's main board with an 80386SX processor daughterboard. Safety, opening the case, the clock chip and head parking are covered in the Amstrad PC3086 Maintenance Guide, and the shared board (links, SIMM sockets, cache and video switches) in the Amstrad PC3286 Maintenance Guide. The points below are particular to the 386SX. Faults are in the Amstrad PC3386SX Troubleshooting Guide.[1][2]
Power supply
[edit | edit source]- Amstrad PC International gives the internal supply as 145 W.[3]
- Set the voltage selector beside the mains inlet before switching on: 200–240 V or 100–120 V.[4]
- No circuit or parts list for the supply has been published; Amstrad's service manual for the range is not online.[5][6]
Memory
[edit | edit source]The 80386SX reads memory 32 bits wide, so all four SIMM sockets must hold identical modules. Only three sizes are possible.[7]
| Total | SIMMs | LK22 | LK21 | LK20 | LK19 |
|---|---|---|---|---|---|
| 1 MB | 4 × 256 KB | In | In | Out | Out |
| 4 MB | 4 × 1 MB | Out | In | In | Out |
| 16 MB | 4 × 4 MB | Out | Out | Out | Out |
Set LK23 and LK24 for the slowest SIMM (80, 100, 120 or 150 ns), as on the PC3286, then run SETUP to divide the memory between base and extended.[7][4] Amstrad's leaflet lists 1 MB as standard; Cliff Lawson's summary of Amstrad's PCs gives the PC3386SX as 4 MB.[8][9]
Processor board
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- The 80387SX co-processor socket is on the daughterboard. Remove the daughterboard from the main board, fit the 80387SX, refit the board and record the co-processor in SETUP. No links change.[2][8]
- LK720 on the daughterboard enables pipelining when fitted and disables it when removed.[1]
- LK500 and LK501, where fitted, stay on pins 1 and 2 on the PC3386SX.[1]
- The Centre for Computing History holds a 386 daughterboard catalogued against the PC3286.[10]
Cache
[edit | edit source]Amstrad lists 64 KB of 35 ns cache as optionally fitted; LK37 and LK42 are both in for 35 ns chips. Switch off the cache for expansion-card memory with LK36 if a bank-switched memory card is fitted.[8][7][1]
Hard disk
[edit | edit source]- The standard drive was a 40 MB IDE disk with 28 ms access; Amstrad PC International identifies it as a Miniscribe, with a 100 MB Conner as the option.[8][3]
- The BIOS drive table includes types with 33 and 34 sectors per track for larger drives (types 32, 33, 34, 37, 47 and 49), and types 50 and 51 take user-defined parameters.[11]
- Amstrad's automatic installation was not written for the 100 MB drive; on the magazine's machine the disk had to be set up by hand.[3]
- Park the heads with PARK.COM before moving the machine.[12]
See Hard Drive Maintenance and Repair.
Capacitors
[edit | edit source]No capacitor values have been published for the PC3386SX's boards or its 145 W supply.[5][6] See Capacitor Failure Symptoms.
Related pages
[edit | edit source]- Amstrad PC3386SX · Amstrad PC3386SX Troubleshooting Guide
- Amstrad PC3286 Maintenance Guide · Amstrad PC3086 Maintenance Guide
- Amstrad PC3086, PC3286 and PC3386SX User Manual
- Recommended Tools
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 11-1 to 11-10. Expansion slots, opening the lid, and the option link tables for the PC3086 and for the PC3286 and PC3386SX.
- ↑ 2.0 2.1 Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 7-1 to 7-7. Processor speeds, fitting an 8087, 80287 or 80387SX co-processor, and opening the system unit.
- ↑ 3.0 3.1 3.2 Thomas Kallay, "Big Brother: AMSTRADs Flaggschiff der Generation 3: der PC3386 SX", Amstrad PC International, February/March 1991, pp. 41–42. Internet Archive. Retrieved 2026-10-02. Specification table and test of a PC3386SX with a 100 MB Conner disk.
- ↑ 4.0 4.1 Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 3-7 to 3-15. Voltage selector, power switch, the "Please wait." self-test dots, start-up messages and BIOS versions, and the SETUP program for the PC3286 and PC3386SX.
- ↑ 5.0 5.1 Centre for Computing History, "Amstrad PC3086 PC3286 PC3386SX Colour Personal Computers Service Manual" (CH27476): 53-page service manual with schematics and wiring diagrams, reference SM-PC3000. Retrieved 2026-10-02.
- ↑ 6.0 6.1 acpc.me (ACME) archive, Amstrad PC section, directory DOCUMENTS_TECHNIQUES/SERVICE_MANUALS. Retrieved 2026-10-02. The PC3086/PC3286/PC3386SX, PC4386SX and PC5086/PC5286 service manuals are listed with placeholder images only, marked missing.
- ↑ 7.0 7.1 7.2 Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 8-6 to 8-10. Memory cache, SIMM upgrades, memory size and DRAM speed links, cache speed links.
- ↑ 8.0 8.1 8.2 8.3 Amstrad plc, PC3386SX leaflet, © August 1990, p. 2 (specification). Hosted as File:Amstrad PC3386SX leaflet (1990).pdf.
- ↑ Cliff Lawson (Amstrad plc), "General notes on Amstrad PCs" (general.htm), as preserved at freetimeweb.nl. Retrieved 2026-10-02. Amstrad's proprietary keyboard and mouse interfaces up to the 4386, PS/2-compatible ones from the 5xxx series, and a summary specification of each PC.
- ↑ Centre for Computing History, "Amstrad PC3286 286 Daughterboard" (CH42246) and "Amstrad PC3286 386 Daughterboard" (CH42247), 1990. Retrieved 2026-10-02.
- ↑ Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 9-1 to 9-3. Built-in IDE adaptors (XT type on the PC3086, AT type on the PC3286 and PC3386SX) and the hard disk type table.
- ↑ Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 13-2 to 13-4. Transporting a hard disk PC, PARK.COM, and replacing the CMOS RAM.