Panasonic FS-A1WX Capacitor Replacement Guide
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No Panasonic parts list for the Panasonic FS-A1WX has been found. BABAX's traced parts list of a WX main board (board DFUP0250ZAU1a) gives the value, voltage and temperature rating of each of its 30 aluminium electrolytic capacitors, and the supply capacitors agree with the power unit diagram in the scanned circuit pages.[1][2] The list notes that parts can differ between production lots, so check the markings on your own board before ordering.[3]
The drive's own capacitors are not in the list. For the Panasonic FS-A1WSX, use this list as a starting point only; see the Panasonic FS-A1WSX Capacitor Replacement Guide.
Main board electrolytics
[edit | edit source]| Positions | Qty | Value | Voltage | Rating | Notes |
|---|---|---|---|---|---|
| C57, C34 | 2 | 3300 µF | 25 V | 85 °C | Reservoirs after D1 and D2; feed the +5 V converter |
| C53 | 1 | 3300 µF | 10 V | 105 °C | +5 V converter output (Vcc2) |
| C70 | 1 | 470 µF | 6.3 V | 85 °C | +5 V line after L6 |
| C36, C35 | 2 | 470 µF | 35 V | 85 °C | Inputs of the 78L12 (+12 V) and 79L12 (−12 V) |
| C55 | 1 | 1 µF | 50 V | 85 °C | −12 V output |
| C58 | 1 | 1000 µF | 6.3 V | 85 °C | |
| C2, C18, C25, C26, C27, C41, C63, C71, C84, C98 | 10 | 470 µF | 6.3 V | 85 °C | |
| C52 | 1 | 100 µF | 6.3 V | 85 °C | |
| C13, C20 | 2 | 22 µF | 50 V | 85 °C | |
| C14 | 1 | 10 µF | 50 V | 85 °C | |
| C42, C43, C45, C46, C85 | 5 | 2.2 µF | 50 V | 85 °C | |
| C12, C28, C64 | 3 | 1 µF | 50 V | 85 °C |
[1][2] The quantities add up to 30. The notes cover the capacitors on the power unit diagram; the traced schematic on page 1 of BABAX's drawing shows where the others sit in the circuit, and page 2 shows the board layout.[3]
Replacing the supply capacitors
[edit | edit source]Unplug the machine and remove the top of the case as described in the maintenance guide.[4] C53 is the only 105 °C part in the list; keep that rating, or better, when replacing it.[1] Bad capacitors in the supply are one of the suspects forum members named for a machine that cuts in and out.[5]
References
[edit | edit source]- ↑ 1.0 1.1 1.2 BABAX, FS-A1WX parts list, revision 02, 5 August 2014, capacitors: C2, C18, C25, C26, C27, C41, C63, C70, C71, C84, C98 470 µF 6.3 V 85 °C; C12, C28, C55, C64 1 µF 50 V 85 °C; C13, C20 22 µF 50 V 85 °C; C14 10 µF 50 V 85 °C; C34, C57 3300 µF 25 V 85 °C; C35, C36 470 µF 35 V 85 °C; C42, C43, C45, C46, C85 2.2 µF 50 V 85 °C; C52 100 µF 6.3 V 85 °C; C53 3300 µF 10 V 105 °C; C58 1000 µF 6.3 V 85 °C. Hosted as File:Panasonic FS-A1WX schematic and parts list (BABAX, Rev 04a).pdf.
- ↑ 2.0 2.1 FS-A1WX circuit diagram, figure 8, "power unit", printed page 63: AC 100 V through the double-pole power switch to transformer T1; a four-pin connector to the board (pin 2 to ground); D1 and D2 into C57 and C34 (25 V, 3300 µF each); DC/DC converter IC7 (MC34063) with switching transistor Q11 (printed "2SA598"), current-sense resistor R96 (0.2 Ω), R97 and R98 (100 Ω), R113 (22 Ω), R114 (68 Ω), timing capacitor C59 (330 pF), catch diode D8, feedback resistors R99 (3.9 kΩ) and R101 (1 kΩ), C54 (0.1 µF) and R95 (330 Ω), inductor L5 to the +5 V (Vcc2) line with C53 (10 V, 3300 µF), then L6 to +5 V with C70 (6.3 V, 470 µF); pin 4 through D7 and D6 to C36 and C35 (35 V, 470 µF) and the 78L12 (IC29, +12 V, with C56 0.1 µF) and 79L12 (IC28, −12 V, with C55 50 V 1 µF) regulators. Lower half: the clock oscillator (IC9 TC40H004P, X2 32.8 kHz), reset IC10 (MN1280R), the 3 V battery connection through D9 and D10, and the backup switching transistors Q8 and Q9. Hosted as File:Panasonic FS-A1WX circuit diagrams (pages 55 to 64).pdf. Reproduced as File:Panasonic FS-A1WX power supply circuit (figure 8).png.
- ↑ 3.0 3.1 BABAX, Panasonic MSX2+ FS-A1WX Schematic, revision 04a, 9 August 2014, traced from a board marked DFUP0250ZAU1a (serial 8KCKB01501), with parts list "FS-A1WX パーツリスト PARTS LIST", 5 August 2014, revision 02. Parts list: IC1 CXA1145M; IC2 TC8566AF; IC3 M60014-0140FP (the drawing labels it "FX/WX gate array"); IC4 T9769A or B; IC5 YM2413; IC6 LM324; IC7 MC34063; IC10 MN1280R; IC11 to IC14, IC22 and IC23 MB81464-12; IC17 and IC18 MB834000; IC19 and IC20 MB8464-15L; IC21 and IC24 81C4256 shown in brackets as unfitted; IC28 79L12; IC29 78L12; Q11 2SA1598; D8 SB540; X1 16.00 MHz; X2 32.768 kHz; X4 21.47727 MHz; T1 transformer DDT5U7J02Z-W; V1 battery 1.5 V × 2; RY1 relay SZ-5; CN1 power in, CN6 RGB (8-pin DIN), CN7 cassette (8-pin DIN), CN13 drive. The drawing labels IC8 V9958 "MSX-VIDEO II"; the parts list gives "V9938 E-VDP-II". The list notes that ROMs and transistors can differ between production lots. Community reverse-engineered drawing, not a Panasonic document. Hosted as File:Panasonic FS-A1WX schematic and parts list (BABAX, Rev 04a).pdf.
- ↑ Panasonic「FS-A1WSX」ゴムベルト交換, 29 November 2015—link(accessed 2026-10-21) The FS-A1WSX's drive is a belt-driven Matsushita EME-213MA. Procedure: remove seven Phillips screws from the underside and lift off the top, unplugging two connectors; remove the four screws holding the drive base and unplug the flat cable; remove the drive's four screws (the screws on the black plate can stay); remove the screw and the white plastic part, and photograph the position of the sensor mounted with the board beside it first, because it is easy to refit wrongly; change the belt; reassemble and test with CALL FORMAT. Melted rubber was stuck to every pulley; left in place, it stops a new belt reading discs; isopropyl alcohol removes it cleanly. The author used a Daiso "D-009" hair band (small size) as a substitute belt, and laid clear tape in the guide groove under the black pulley to stop the belt slipping into the gap between the pulley and the metal frame.
- ↑ FS-A1WSX powering off/resetting until I tap the machine, December 2023 to January 2024—link(accessed 2026-10-21) pawlicker: an imported FS-A1WSX, run from a 120 V to 100 V step-down adapter, switched itself off and on until the top of the case was tapped; reflowing the power switch did not help. sd_snatcher: not a common fault on these machines; suspect broken solder joints or bad capacitors in the supply, the internal connector to the transformer, or the power switch; Panasonic, Sony and Sanyo MSX machines run on about 127 V 60 Hz without a step-down transformer, unlike Toshiba ones. NYYRIKKI: if the power LED reacts to tapping, it is the supply; measure the voltages. maxis: a typical sign of a dry joint; inspect every joint with magnification. Pencioner: oxidised contacts inside the switch itself can cause it and make the switch hot. Wierzbowsky: inspect the board from both sides, starting with the AC power connector and the AC-DC section. MSXcri: his FS-A1WX's reset button sometimes stuck down, making the machine reset continuously until the button was freed.