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Panasonic JR-200 Capacitor Replacement Guide

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Power supply section of the JR-200U schematic (service manual p. 21)

The Panasonic JR-200 has ten electrolytic capacitors, all on the main board. Panasonic's parts list for the U.S. JR-200U gives their values and part numbers; the list below is taken from it.[1] Japanese and PAL boards may differ from the U.S. board; the PAL JR-200UP, for one, uses a different clock crystal.[2]

Capacitor list

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JR-200U electrolytic capacitors (parts list, section 16)
Ref Capacitance Voltage Panasonic part
C1, C35 33 µF 10 V ECEA1AS330
C31 2.2 µF 50 V ECEA1HS2R2
C32, C34, C41 100 µF 10 V ECEA1AS101
C33 330 µF 10 V ECEA1AS331
C36 470 µF 10 V ECEA1AS471
C37 1000 µF 10 V ECEA1AS102
C38 470 µF 50 V ECEA1HS471

[1]

Power supply capacitors

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On the schematic, C38 (470 µF, 50 V) is the reservoir after the bridge rectifier DB1 and the noise filter FL2, at the input of the regulator IC34. C37 (1000 µF, 10 V) is the output capacitor after the choke L2 on the +5 V rail. The other capacitors on the rail after C37 are 22000 pF ceramics.[1]

Procedure

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  1. Unplug the computer. The transformer primary is mains-connected, and the power switch is on the mains side.[1]
  2. Open the case as described on the Panasonic JR-200 General Maintenance page, taking care of the keyboard's multi lead.[1]
  3. Note the polarity of each capacitor before removing it.
  4. Fit parts of the same capacitance and at least the same voltage rating.
  5. Switch on and measure the +5 V rail at C37 before refitting the case. Panasonic's flowchart for a dead machine ends with the question of whether IC34 supplies 5 V.[1]
  6. Run Panasonic's RAM and ROM tests to confirm the board; see the Panasonic JR-200 Troubleshooting Guide.
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References

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  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Matsushita Engineering and Service Company, Service Manual: Personal Computer JR-200U, order no. EDCD 83-001: power supply schematic p. 21 (PDF page 23); section 16 "Replacement Parts List", main circuit board and keyboard (PDF page 79). Hosted here as File:Panasonic JR-200U Service Manual EDCD 83-001.pdf; see Panasonic JR-200 Documentation.
  2. ↑ Markku Reunanen, Discovering the Panasonic JR-200U—link(accessed 2026-10-01) Hardware notes on NTSC and PAL differences.


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