Casio PV-16 Capacitor Replacement Guide
No parts list, capacitor list or circuit diagram for the Casio PV-16 has been published. The PV-16 has no mains supply inside: it runs from 10 V DC from the AD-4110 adaptor or the KB-7 expansion unit, and a µPC7805H regulator on the main board makes +5 V.[1][2]
What is known
[edit | edit source]The main board is printed with the value and working voltage beside each electrolytic capacitor. These markings can be read in the photograph on the MSX Resource Center wiki:[2]
| Position | Board marking |
|---|---|
| Next to the µPC7805H regulator | 100 µF 25 WV |
| To the lower right of the regulator | 100 µF 6.3 WV |
| Near the 74LS139 | 47 µF 6.3 WV |
| Left edge, by a 1S1588 diode | 47 µF 6.3 WV |
| Round the LA6358 and the audio and video sockets | 10 µF 6.3 WV, 10 µF 16 WV, 1 µF 25 WV |
| CPU board C2305-1 | 47 µF 6.3 WV |
[3] The 25 V part beside the regulator is the one that sees the adaptor's unregulated 10 V; keep its replacement at 25 V.[2][4] On one PV-16 that went to a black screen, none of the capacitors leaked or bulged.[5]
Which to replace first
[edit | edit source]Advice on the MSX Resource Center forum is to replace the main supply's capacitors whatever their condition, to judge the capacitors in the audio and video circuits by the sound and picture, and to leave the small decoupling capacitors spread over the board unless there is a reason to change them.[6] On the PV-16 that means:
- The 100 µF 25 V and 100 µF 6.3 V capacitors round the regulator.
- The capacitors round the LA6358 and the audio and video sockets, if the picture or sound is poor.
- The rest, only if they leak, bulge or a rail is noisy.
Recording the board
[edit | edit source]- Unplug the adaptor or the KB-7 and open the case as described in the Casio PV-16 General Maintenance guide.
- Photograph both boards from above, then each electrolytic close up with the board marking beside it.
- For each capacitor, write down the board marking, the printing on the capacitor, its diameter and height, and which side the stripe faces.
- Order replacements of the same capacitance, at least the same voltage, and a size that fits.
| Position | Board marking | Printed on the capacitor | Diameter × height | Notes |
|---|---|---|---|---|
| Next to the regulator | 100 µF 25 WV | |||
| Lower right of the regulator | 100 µF 6.3 WV | |||
| Audio and video | ||||
| CPU board | 47 µF 6.3 WV |
Procedure
[edit | edit source]The PV-16 carries no mains voltage inside.[1]
- Unplug the adaptor or the KB-7 from the computer.
- Replace one capacitor at a time, with the stripe on the same side as the original.[6]
- On the CPU board, work with it in place if it is soldered to the main board.[7]
- Make sure no capacitor lead or ceramic capacitor touches a wire link when you have finished.[5]
After the recap
[edit | edit source]Measure +5 V at the cartridge slot, between pin 45 or 47 and pin 41.[8] Pins 48 and 50 read nothing on the PV-16, because its slot has no ±12 V.[8] Any remaining fault is covered in the Casio PV-16 Troubleshooting Guide.
Related pages
[edit | edit source]- Casio PV-16
- Casio PV-16 General Maintenance
- Casio PV-16 Troubleshooting Guide
- Casio PV-7 Capacitor Replacement Guide
- Capacitor Failure Symptoms
References
[edit | edit source]- ↑ 1.0 1.1 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 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. Silkscreen markings read from it: "100µF 25WV" beside an electrolytic next to the µPC7805H regulator; "100µF 6.3WV" beside an electrolytic to the lower right of the regulator; "47µ 6.3WV" near the 74LS139; "10µF 6.3WV", "10µF 16WV" and "1µF 25WV" round the LA6358 op-amp and the audio and video sockets; "47µF 6.3WV" beside an electrolytic at the left edge, next to a 1S1588 diode. Other markings are too small to read in the photograph.
- ↑ Photograph of the PV-16 CPU board (File:Casio PV-16 CPU board.jpg), uploaded to the MSX Resource Center wiki by Gdx on 15 February 2016: board C2305-1 with electrolytics marked "47µF 6.3WV".
- ↑ Casio PV-16, 24 July 2026—link(accessed 2026-10-21) AC adaptor AD-4110: input AC 100 V, 50/60 Hz, 14 VA; output up to 800 mA, unregulated DC 10 V, centre negative.
- ↑ 5.0 5.1 Black Screen, March 2018—link(accessed 2026-10-21) cobracon2, 13 March 2018: checked all the caps on a PV-16 with a black screen; no leaks or bulges. gdx, 16 March 2018: check that the ceramic capacitors do not touch the straps.
- ↑ 6.0 6.1 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.
- ↑ Black Screen, 13 March 2018—link(accessed 2026-10-21) cobracon2: the PV-16's CPU board would not come off and appears to be soldered; Grauw agreed after a second look at the photographs.
- ↑ 8.0 8.1 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; 50 −12 V. The ±12 V supplies are not connected on Casio MSX machines.
