Sanyo MPC-200 General Maintenance
The Sanyo MPC-200 is the Spanish version of Sanyo's MPC-2, an MSX1 computer of 1985 with its power supply inside the case.[1] Sanyo published no service manual for it. Its Spanish operating instructions, photographs of opened machines and the MSX standard are the sources for the checks below.
Mains supply
[edit | edit source]- The rating label gives 220 V, 50 Hz and 6 W. A second label in Spanish says not to open the computer without first disconnecting it from the mains.[2]
- The mains lead is fixed to the case and has a two-pin European plug.[3] Check the lead for cracks where it enters the case.
- Inside, the mains transformer is labelled PT0129 and the fuse beside it, F101, is marked T1A 250V.[4] Replace a blown fuse only with the same rating, and find out why it blew first.
Warning: the transformer's primary, the fuse and the mains lead carry mains voltage while the machine is plugged in. Unplug it before opening the case.
Cleaning
[edit | edit source]Sanyo's instructions are to clean the computer with a dry cloth and never to use chemicals such as solvents or petrol. Keep it away from heat, damp, dust and direct sunlight, and keep drinks away from it.[5] If the computer smokes or makes unusual noises, switch it off at once.[5]
Cartridges
[edit | edit source]Switch the computer off before inserting or removing a cartridge, and push it in gently. Both the manual and a label beside the slots give this instruction.[6][7] Clean a cartridge's edge contacts with isopropyl alcohol before blaming a slot.
Checking the supply rails
[edit | edit source]The cartridge slots follow the MSX standard, so the supply can be checked there without opening the case. Measure against pin 41 or 43.[8]
| Pin | Signal |
|---|---|
| 41, 43 | Ground |
| 45, 47 | +5 V |
| 48 | +12 V |
| 50 | −12 V |
The MSX standard requires the +5 V supply to deliver up to 300 mA to each slot, and the ±12 V supplies up to 50 mA for all slots together.[8] Keep that in mind before running power-hungry cartridges in both slots at once. Sanyo published no tolerances for the MPC-200's rails.
Opening the case
[edit | edit source]Sanyo published no disassembly procedure. With the top cover off, the transformer and fuse are at the back left, the main board fills the lower case, and a separate board behind the cartridge connectors and a small board carrying a lamp are joined to it by leads.[4] Photograph the leads before unplugging any of them. The T7775 MSX-Engine is a surface-mounted chip on the underside of the main board, so lift the board with care and do not flex it.[9]
Reset button
[edit | edit source]The reset button on the top has the same effect as switching off and on again: it clears any program in memory. Use it when the STOP key does not respond.[10]
Cassette
[edit | edit source]The cassette interface records by FSK at 1200 or 2400 baud.[11] If CSAVE or CLOAD fails, Sanyo's advice is to follow the procedure in chapter 4, clean the data recorder's head and adjust its volume.[12]
Capacitors
[edit | edit source]The supply has two large electrolytic capacitors next to the heatsink, and there are smaller ones across the main board.[4] No values have been published. The Sanyo MPC-200 Capacitor Replacement Guide describes how to record and replace them.
Related pages
[edit | edit source]- Sanyo MPC-200
- Sanyo MPC-200 Troubleshooting Guide
- Sanyo MPC-200 Capacitor Replacement Guide
- Sanyo MPC-200 Operating Instructions
- Recommended Tools
References
[edit | edit source]- ↑ Sanyo MPC-200, MSX Resource Center wiki—link(accessed 2026-10-21) Community specification page: the MPC-2 localised for Spain, 1985; internal power supply; Toshiba T6950 VDP, Toshiba T7775 MSX-Engine; two cartridge slots.
- ↑ File:Sanyo MPC-200 rating label.jpg, labels photographed for the MSX Resource Center wiki by Mars2000you: "Model MPC-200(SP)", "Service Ref. No. MPC-200(SP)-00", 220 V, 50 Hz, 6 W; "No abrir sin antes desconectar la tensión de red".
- ↑ File:Sanyo MPC-200 rear.jpg, photograph uploaded to the MSX Resource Center wiki by Gdx: rear connectors and the fixed mains lead with a two-pin European plug.
- ↑ 4.0 4.1 4.2 File:Sanyo MPC-200 inside.jpg and File:Sanyo MPC-200 power supply area.jpg, photographs of an opened MPC-200 uploaded to the MSX Resource Center wiki by Rderooy. Read from them: transformer PT0129 at the back left; fuse holder F101 marked "T1A 250V"; two large electrolytic capacitors side by side next to a part on a black heatsink; a column of four diodes below; main board labelled UF063481 and marked MCL437F; board SANYO EB1402 behind the cartridge connectors.
- ↑ 5.0 5.1 Sanyo, Ordenador personal MSX: Instrucciones para el funcionamiento (MPC-200), page 12, "Precauciones": switch off and contact the dealer at any abnormal sign (smoke, unusual noises); avoid knocks and falls; avoid hot, damp or dusty places and direct sunlight; do not spill drinks on it; internal parts can cause electric shock; clean with a dry cloth, without solvents or petrol. In Spanish. Hosted here as Sanyo MPC-200 Operating Instructions.
- ↑ Sanyo, Instrucciones para el funcionamiento (MPC-200), page 4, "Conexión con el Cartucho": two cartridge slots for games or MSX interface units; "Desconecte el computador antes de la conexión del Cartucho. Insértelo suavemente." See Sanyo MPC-200 Operating Instructions.
- ↑ File:Sanyo MPC-200.jpg, photograph uploaded to the MSX Resource Center wiki by Mars2000you, showing Sanyo's "Atención" label beside the slots: before inserting a cartridge, make sure the equipment is switched off, to avoid damage to the cartridge and the computer.
- ↑ 8.0 8.1 MSX Cartridge slot, MSX Resource Center wiki—link(accessed 2026-10-21) Standard MSX cartridge slot pinout: pins 41 and 43 GND, 45 and 47 +5 V, 48 +12 V, 50 −12 V; the +5 V supply must be able to supply up to 300 mA per slot, and the ±12 V supplies up to 50 mA for all slots together.
- ↑ File:Sanyo MPC-200 T7775 MSX-Engine.jpg, photograph of the underside of the main board uploaded to the MSX Resource Center wiki by Rderooy: surface-mounted Toshiba T7775 MSX-Engine.
- ↑ Sanyo, Instrucciones para el funcionamiento (MPC-200), page 6, "El botón del RESET": pressing reset has the same effect as switching off and on; press it when the STOP key does not work; programs in memory are erased. See Sanyo MPC-200 Operating Instructions.
- ↑ Sanyo, Instrucciones para el funcionamiento (MPC-200), page 14, "Especificaciones": cassette interface FSK, 1200/2400 baud; power supply local mains voltage, 50/60 Hz, 6 W. See Sanyo MPC-200 Operating Instructions.
- ↑ Sanyo, Instrucciones para el funcionamiento (MPC-200), page 13, "Problemas": table of symptoms and points to check. See Sanyo MPC-200 Operating Instructions.
