Casio PV-16 General Maintenance
The Casio PV-16 runs from an external adaptor, like the Casio PV-7 it replaced. Casio's service documentation for it has not been published. The notes below use the MSX Resource Center wiki, photographs of the boards and repairs and modifications reported by owners; the Casio PV-7 General Maintenance guide covers the earlier model.
Power
[edit | edit source]- The PV-16 is rated at 10 V DC, 8 W, and takes its power from the AC adaptor AD-4110 or from the KB-7 expansion unit.[1]
- The AD-4110 takes 100 V AC, 50/60 Hz, 14 VA, and gives unregulated 10 V DC at up to 800 mA, centre negative.[2] On 230 V mains, use a step-down transformer or a replacement adapter.
- A replacement adapter needs to give about 10 V DC with the centre negative and at least 800 mA. Check the polarity of its plug with a meter before connecting it.
- The power jack and the power switch are at the top edge of the main board, and +5 V comes from a µPC7805H regulator beside them. The board is marked 100 µF 25 WV beside an electrolytic next to the regulator, and 100 µF 6.3 WV beside another to its lower right.[3]
- On one PV-16 that had gone to a black screen, the adaptor and the regulator were both working, the regulator giving 5.2 V.[4]
Measuring the supply
[edit | edit source]Measure +5 V at the cartridge slot, between pin 45 or 47 and ground on pin 41 or 43.[5] Pins 48 and 50, the ±12 V pins on other MSX machines, are not connected on the PV-16, so cartridges that need ±12 V, such as the FM-PAC, do not work in its slot without modification.[2]
Inspection
[edit | edit source]Advice given to a PV-16 owner on the MSX Resource Center forum was to check that no ceramic capacitor touches the board's wire links and to check all the solder joints.[4] The CPU board, with the CPU, ROM and RAM, is soldered to the main board on at least some machines, so check it in place before trying to remove it.[4]
Opening the case
[edit | edit source]No disassembly procedure has been published.
- Unplug the adaptor or the KB-7, the television lead, the joysticks and the data recorder, and remove any cartridge.
- Turn the machine over on a soft surface and photograph the underside, so each screw can go back where it came from.
- Remove the screws that hold the case together and lift the top half a little at a time.
- Photograph the keyboard connection and any wires between the halves before unplugging them.
Expansion
[edit | edit source]The KB-7 adds two cartridge slots and a printer port.[2] One owner reports that the KB-7's connector fits the PV-7 but faces differently from the PV-16's, which faces the back of the case; a short extension cable was suggested.[6] RAM upgrades beyond 16 KB put the new RAM in slot 2, which rules out the KB-7.[6]
Capacitors
[edit | edit source]Advice on the MSX Resource Center forum is to replace the main supply's capacitors whatever their condition, to judge the audio and video capacitors by the picture and sound, and to leave the small decoupling capacitors unless there is a reason to change them.[7] What is known of the PV-16's capacitors is in the Casio PV-16 Capacitor Replacement Guide.
Related pages
[edit | edit source]- Casio PV-16
- Casio PV-16 Troubleshooting Guide
- Casio PV-16 Capacitor Replacement Guide
- Casio PV-7 General Maintenance
- Recommended Tools
References
[edit | edit source]- ↑ Moulded rating label of a black PV-16 (File:Casio PV-16 rating label.jpg), uploaded to the MSX Resource Center wiki by Mars2000you on 17 October 2016: "PV-16BK, RATING: DC 10V, 8 W; use AC ADAPTOR AD-4110 or KB-7".
- ↑ 2.0 2.1 2.2 Casio PV-16, 24 July 2026—link(accessed 2026-10-21) Power adapter input must be AC 100 V, 50/60 Hz, 14 VA; it can output up to 800 mA with an unregulated voltage of DC 10 V, centre negative; adapter reference AD-4110. The AC power adaptor is required if the KB-7 unit, which has its own power supply, is not used. Cartridge connector pins SW1, SW2, −12 V and +12 V are not connected; some cartridges need ±12 V, for example the FM-PAC.
- ↑ Photograph of the PV-16 main board (File:Casio PV-16 main board.jpg), uploaded to the MSX Resource Center wiki by Gdx on 15 February 2016: power jack HEC0470-01-230 (marked POWER JACK) and power switch at the top edge; µPC7805H regulator; silkscreen "100µF 25WV" beside an electrolytic next to the regulator and "100µF 6.3WV" beside another to its lower right.
- ↑ 4.0 4.1 4.2 Black Screen, March 2018—link(accessed 2026-10-21) cobracon2, 13 March 2018: the power supply checked good and the regulator was putting out 5.2 V; no capacitors were leaking or bulging; the CPU board would not come off and appears to be soldered. gdx, 16 March 2018: check that the ceramic capacitors do not touch the straps, and check all the solder joints, as the machine is very old.
- ↑ MSX Cartridge slot, 6 July 2026—link(accessed 2026-10-21) Pin table: 41 and 43 GND; 45 and 47 +5 V; 48 +12 V; 49 SOUNDIN; 50 −12 V. The ±12 V supplies are not connected on Casio MSX machines, among others.
- ↑ 6.0 6.1 Casio PV-16 upgrade to 32kb on slot 0 won't work, November 2023 to February 2024—link(accessed 2026-10-21) lmanes, 6 February 2024: KB-7 units fit the PV-7 but not the PV-16 or the MX line; the connectors are the same but the PV-16 and MX connectors face back and the PV-7's faces down. gdx, 7 February 2024: a small extension cable should solve it. Earlier in the thread: a 32 KB static RAM fitted in slot 0 in place of the two 8 KB chips still gave only 16 KB; gdx (4 December 2023) found that the MB64H131 seems to filter /SLTSL0 for the page 3 RAM only, so the known 64 KB upgrades wire the RAM to /SLTSL2, after which the KB-7 can no longer be used.
- ↑ Recap recommendations, June 2018—link(accessed 2026-10-21) Reply by RetroTechie, 23 June 2018: main power supply capacitors in an MSX are worth replacing whatever their condition; audio and video capacitors show their condition in the output; bypass capacitors round the board can often be removed without the machine stopping; replace one at a time to avoid mixing up values or polarity.
