Amstrad PC3386SX Troubleshooting Guide
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Fault-finding for the Amstrad PC3386SX. Its main board is the Amstrad PC3286's, so the start-up messages, self-test dots and fatal errors in the Amstrad PC3086 Troubleshooting Guide and the board faults in the Amstrad PC3286 Troubleshooting Guide apply. The points below concern the 386SX processor board, its memory rules, the larger hard disk option and the memory managers. Procedures are in the Amstrad PC3386SX Maintenance Guide.[1][2]
Symptoms
[edit | edit source]| Symptom | Likely cause | Action |
|---|---|---|
| Memory errors at start-up after an upgrade | The 386SX needs four identical SIMMs; two-SIMM and mixed fits allowed on the PC3286 are not allowed here | Fit four matching SIMMs for 1, 4 or 16 MB and set LK19 to LK22 to suit[3] |
| Memory errors with slower SIMMs | DRAM speed links set for faster chips | Set LK23 and LK24 for the slowest SIMM fitted[3] |
| "Error: Faulty CACHE RAM" | Optional 35 ns cache chips faulty or loose | Check the chips and LK37 and LK42; DEVICE CACHE OFF runs the machine without the cache[1][4]
|
| Machine appears slow | Processor speed reduced in SETUP or by DEVICE, or a LIMulator in use | DEVICE SPEED returns 120 for a 20 MHz 80386SX; the manual warns that MEMM.SYS /E slows the PC noticeably[4][5]
|
| Expanded memory problems under MS-DOS | A conventional LIM-EMS driver loaded with a LIMulator, or MEMM.SYS /E loaded before HIMEM.SYS | Use one or the other, and load HIMEM.SYS before MEMM.SYS /E[5] |
| 100 MB hard disk not set up by the installation disk | Amstrad's automatic installation was written for the 40 MB drive | Set the drive type in SETUP and prepare the disk by hand[6][7] |
| Co-processor not used by software | SETUP still records no co-processor | Set the co-processor in SETUP after fitting an 80387SX[8][9] |
| 800 × 600 modes do not display | The 800 × 600 modes need a multi-frequency monitor | Use a multi-frequency monitor and set video DIP switch 1 on[6][10] |
Checking the processor board
[edit | edit source]- Switch off, open the case as described in the PC3086 guide, and remove the daughterboard.[2][8]
- Check LK720 on the daughterboard (fitted for pipelining) and, where present, LK500 and LK501 on pins 1 and 2.[2]
- Refit the daughterboard, switch on and count the self-test dots under "Please wait.".[8][1]
Final notes
[edit | edit source]- Amstrad GmbH's interrupt table is the same as the PC3286's: IRQ 3, 10, 11, 12 and 15 free, IRQ 5 mouse, IRQ 13 co-processor, IRQ 14 hard disk.[11]
- See also Capacitor Failure Symptoms and Hard Drive Maintenance and Repair.
References
[edit | edit source]- ↑ 1.0 1.1 1.2 Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 14-1 to 14-3. Non-fatal and fatal hardware error messages.
- ↑ 2.0 2.1 2.2 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.
- ↑ 3.0 3.1 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.
- ↑ 4.0 4.1 Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 4-2 to 4-18. The DEVICE command: display, floppy drive, cache, memory map and processor speed settings.
- ↑ 5.0 5.1 Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 8-2 to 8-5. Base, expanded and extended memory, HIMEM, and LIMulators (MEMM.SYS /E) on the PC3386SX.
- ↑ 6.0 6.1 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.
- ↑ 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.
- ↑ 8.0 8.1 8.2 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.
- ↑ 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.
- ↑ Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 6-5 to 6-15. PS/2 and AT video modes, disabling the built-in VGA, links 901 and 902, and the video DIP switches.
- ↑ "AMS-Line: Der Informationsdienst der Firma AMSTRAD", Amstrad PC International (page header CPC), August/September 1991, p. 7. Internet Archive. Retrieved 2026-10-02. Amstrad GmbH's column: the meaning of the start-up dots, the PC4386SX BIOS indicator, and the interrupt and I/O address tables of the PC3086, PC3286 and PC3386SX.