Recap guide
Recap the Roland MT-32 and CM-32L
About 20 electrolytics, including bipolars. Several owners measured the original Sanyo caps as mostly in spec, yet LAPC-I owners reported lost or muffled channels cured by replacing every electrolytic.
Open the interactive checklist Tick off each capacitor as you replace it. It saves in your browser.
Check first. A recap is not always the answer here, so look at the guides before you order parts.
Which board do I have?
Boards changed during production. These notes come from the linked sources, and many are only partly documented, so check the board in front of you.
- MT-32 old (rev 0) (Medium confidence). How to tell: No headphone jack on the rear; serial numbers up to 851,399 per Wikipedia, early LA32 in an 80 pin PGA package. Capacitors: A VOGONS thread says the only cap difference between old and new revisions is one extra bipolar cap on the old boards and fewer caps overall on newer ones; service manuals list 4 or 5 electrolytics but 20 or 21 are fitted. Console5 sells a kit for early units. Capacitor list differs from other revisions: yes. Source
- MT-32 new (rev 1, headphone jack) (Medium confidence). How to tell: Stereo headphone jack on the rear panel and faster Intel P8098 CPU; serials from 851,400 upward on Wikipedia's list. Capacitors: Same VOGONS thread: fewer caps overall than the old revision. One owner found C40 and C41 (470uF 16V input filters) bulged. Originals were Sanyo with KMG bipolars. Capacitor list differs from other revisions: yes. Source
- CM-32L (Low confidence). How to tell: Rack style unit with only a volume knob, MIDI message and power LED; early units resemble the new MT-32 inside. Capacitors: No capacitor information found for the CM-32L. Capacitor list differs from other revisions: not known. Source
Where to start
Clues from write-ups and forum threads, not a diagnosis. Low confidence means one thread or one repair; high means several write-ups agree.
- Bulged or weak caps (Low confidence). One MT-32 had bulged 470uF/16V caps C40 and C41, and another had two 1000uF PSU filter caps near the 7805 down to roughly 60-70% of their rating. Source
- Muffled or missing channel (LAPC-I) (Low confidence). On an LAPC-I card, right-channel loss and muffled sound were cured by replacing all the electrolytics, according to one thread. Source
- A recap can backfire (Low confidence). In one thread an MT-32 went silent after a recap because of bad joints and lifted pads, with no audible improvement. Source
Tips, tales and maybes
Found in write-ups and forum threads. These are other people's reports, not tested by us. Check part references and values against your own board.
- Watch out: Bent capacitor leads shorted an LAPC-I (Medium confidence). An LAPC-I that arrived dead had the long leads of C33 bent so two touched each other and a pin of IC22. Straightening them with pliers brought it back to life. The author says the card needs a rigid protective box for storage, since an anti-static bag or bubble wrap is not enough. Source
- Tip: LAPC-I recap rules from a thread (Medium confidence). A thread on an LAPC-I that cut out or lost a channel says replacing all electrolytics fixed it, using low-ESR radials of the same uF, equal or higher voltage, and not switching capacitor type. Negative leads go to the pads marked with circles, and a damaged 4MHz crystal near C33 was also found. Source
- Story: Distorted mids and lows was a ROM, not caps (Medium confidence). An MT-32 with distorted mid and low frequencies, a clean self-test and capacitors and PCM54HP already replaced was eventually fixed after about four months by replacing IC37, a ROM-type chip, with a programmed substitute. Check logic and ROM before blaming sound-path caps. Source
- Story: Originals still tested good (Low confidence). After a recap with Nichicon FW and MUSE BP bipolar caps that went silent until three cold joints were fixed, the poster said the original caps had still tested good and he heard no improvement. One person's experience, not a rule. Source
Before you start
- Boards changed during production. Check your board number against the guides before you order parts.
- A mains power supply can hold a dangerous charge. If you are not trained to work on one, have a professional do it.
Guides we used
This page and the interactive bench are built from these. They have the photos and the full detail, so please read them and support their authors.
- MT-32 Capacitor map and list of caps? (Forum) by CrossBow777 and VOGONS members. Has a capacitor list. Best single source: capacitor map and parts list for Rev 0/1 boards, later corrected, plus an updated spreadsheet of Nichicon equivalents; thread also mentions a Console5 kit and a video
- MT-32 completely silent after capacitor replacement. (Forum) by Paddan1000 and VOGONS members. Cautionary write-up: Nichicon FW/MUSE BP recap, then silence from bad joints and lifted pads; no audible improvement; ESR test results on page 2
- Faulty LAPC-I (Forum) by DonutKing and VOGONS members. LAPC-I symptom fixed by replacing all electrolytics; tips on radial low-ESR parts, polarity marks and the CM32L control ROM v1.02 fix
- MT-32 help with jumper wires (Forum) by VOGONS forum thread. Recapping accident (damaged vias) with ESR measurements showing old caps still near spec; useful counterweight and repair advice
The capacitor list
We have not checked a capacitor list for this machine yet, so none is shown. Follow the guide above for your board, then add the capacitors in the interactive checklist and it builds a shopping list for you.
Skip the sourcing
While you are in there
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Steps, tools and safety
The steps, the tools in top, middle and budget picks, and the safety list are the same for every machine, so they live on one page: How to recap, step by step.
Values are shown as published in the guides above, and boards changed during production. Check the board in front of you. A recap involves hot tools and, on some machines, dangerous voltages. You do it at your own risk.