Amstrad CTM-640
| Amstrad CTM640 | |
|---|---|
 |
|
| CTM640 colour monitor with a CPC 464 | |
| Manufacturer | Amstrad Consumer Electronics plc |
| Type | Colour monitor and system power supply |
| Interface | 6-pin DIN (RGB and sync), 5 V DC lead |
| Compatible | Amstrad CPC 464 |
| Dimensions | 375 × 340 × 365 mm |
| Weight | 10.6 kg |
| Successor | Amstrad CTM-644 |
| Model | CTM640 |
| Power | 240 V AC 50 Hz |
The Amstrad CTM640 is the colour monitor sold with the Amstrad CPC 464 from its launch in 1984. The CPC 464 has no mains input of its own: Amstrad's specification gives the power supply as "Screen System: 240V AC 50Hz (keyboard and datacorder power supplied by screen system)", with the computer's 5 V "supplied exclusively from screen".[1] The CPC 464 system cost £359 with the colour monitor at launch, against £249 with the green screen.[2] When Amstrad added disc drives with the CPC 664, it replaced the CTM640 with the Amstrad CTM-644, which adds a 12 V output for the drive.[2]
The CTM640 contains a CRT and a mains switch-mode supply. Read CRT Discharge Procedure before opening it.
Specifications
[edit | edit source]| Item | Value |
|---|---|
| Mains supply | 240 V AC 50 Hz, switch SW501 |
| Mains fuse | F501, 2 A time-lag (part 1400253) |
| Output | 5 V to the computer, set with VR501 |
| CRT | V001, 3701B22-TC20 (part 170307) |
| Line output transformer | FB401, 3714004 (part 170467) |
| Switching transformer | T501, 8142004 (part 170465) |
| Main ICs | LA7800 (IC401), µPC1378H (IC402), STK7308 (IC501), L78MG (IC502) |
| Boards | Main PCB MM0002A, CRT PCB MS0003 |
| Dimensions, weight | 375 × 340 × 365 mm, 10.6 kg |
The figures are from the specification, parts lists and PCB drawings of the CPC464 manual.[1]
Differences from the CTM644
[edit | edit source]The two monitors share most of their circuit, presets and part numbers, and CPC Amstrad International described them in 1992 as differing only in the CTM644's 12 V supply.[3] The parts lists show more than that:[1][4]
| Position | CTM640 | CTM644 |
|---|---|---|
| IC503 | Not fitted | µPC78M12 12 V regulator |
| J501 | Not listed | DC jack for the 12 V lead |
| C424 | 1000 µF 25 V | 2200 µF 25 V (same part number, 170425) |
| C443, C522, C523 | Not listed | 100 µF 16 V, 470 µF 35 V, 100 µF 16 V |
| T501 | 8142004 (170465) | 8142006 (170845) |
| D501–D504 | 1N4007 (printed "IN4007") | 20E10 |
| D404, D506, D508 | RGP-10K | DFC10E |
| L503 | 47 µH coil | Not listed |
Faults and maintenance
[edit | edit source]Amstrad's basic hardware analysis for the CPC 464 starts at the monitor: the mains fuse, then the DC output and lead, then the computer.[1] The alignment procedure and voltage chart are the same as for the CTM644. The CTM640's parts list, safety test and its own figures are in the Amstrad CTM-640 Maintenance Guide; the full alignment and supply procedures are in the Amstrad CTM-644 Maintenance Guide.
Documentation
[edit | edit source]- Amstrad CPC 464 Service Manual – CTM640 cabinet and electrical parts lists, alignment instructions, voltages, circuit diagram and PCB
Related pages
[edit | edit source]- Amstrad CTM-640 Maintenance Guide · Amstrad CTM-644 · Amstrad CTM-644 Maintenance Guide
- Amstrad CPC 464 · Amstrad CPC 464 Maintenance Guide
- CRT Discharge Procedure · Capacitor Failure Symptoms
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 Amstrad Consumer Electronics plc, CPC464 Micro Computer / CTM640 Colour Monitor / GT64 Green Monitor Service Manual. Described at Amstrad CPC 464 Service Manual. Technical specification and safety test p. 2; CTM640 cabinet drawing and parts list p. 22; electrical parts list pp. 23–24; alignment instructions p. 23; voltages p. 24; circuit diagram and PCB on the back pull-out.
- ↑ 2.0 2.1 Wikipedia, "Amstrad CPC", sections "CPC 464" and "CPC 664". Retrieved 2026-10-01. Launch prices of the CPC 464 with each monitor; the 12 V supply added for the 664 by the GT-65 and CTM-644.
- ↑ Jörg Gurowski, "Hinter Glas – Ein Blick in den Farbmonitor des CPC", CPC Amstrad International (1992). Transcribed at CPCrulez. Retrieved 2026-10-01. In German.
- ↑ Amstrad Consumer Electronics plc, CPC6128 Micro Computer / CTM644 Colour Monitor / GT65 Green Monitor Service Manual, CTM644 parts lists pp. 26–28. Described at Amstrad CPC 6128 Service Manual.