VOGONS


First post, by CrossBow777

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I've downloaded 2 different service manuals for the MT-32, however, both of them only list like 4 or 5 actual electrolytic caps in the parts list? But all the photos of the mainboards I've seen for the Rev 0 and Rev. 1 boards have more like 20 or 21 electrolytic caps on boards. I know some of them are non-polar/bi-polar caps. But I would think that someone somewhere has listed these all out to make it easier to purchase them together?

Or is there actually a kit someone has put together already similar to how I can purchase cap kits for old consoles and my arcade monitor chassis boards?

On the subject of the non-polar/bi-polar caps, has anyone just tried to use standard polarized caps putting the negative side to ground on the traces?

g883j7-2.png
Midi Modules: MT-32 (OLD), MT-200, MT-90, SD-20

Reply 1 of 5, by CrossBow777

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Wanted to update this thread..

Working with Console5.com, there is now a capacitor replacement kit available for the MT-32 early revision units (Without headphone jack). I do want to mention that on the capacitor list there is an error. I've mentioned this to Console5 already, but he hasn't corrected it yet. The error is:

It lists C7 on the capacitor list, but this is incorrect. It is actually C3 labeled on the main PCB and this is correct in the capacitor map diagram listed on the page. Aside from that, the rest seems to be fine. Do the MT-32s need their caps replaced? Well I've not heard of any with exploded or leaking caps. But most of them are Sanyo branded caps with the bi-polar ones being KMG chemical brand. At least they were on mine. After 30years, it wouldn't be a bad idea to replace them out.

g883j7-2.png
Midi Modules: MT-32 (OLD), MT-200, MT-90, SD-20

Reply 2 of 5, by CrossBow777

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Console5 has corrected the mis-print on the capacitor list. I've already gone one of the kits sent to me on hand and will be replacing mine out this week at some point. I might have to break down and do the MT-200 next. If I had the other modules I'd likely cover those as well, but for now at least the earlier rev MT-32 is taken care of. It looks like the only difference in caps between the old and new revs is 1 additional bipolar cap and fewer caps overall on the newer revs.

Last edited by CrossBow777 on 2019-02-06, 02:45. Edited 1 time in total.

g883j7-2.png
Midi Modules: MT-32 (OLD), MT-200, MT-90, SD-20

Reply 4 of 5, by CrossBow777

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keropi wrote:

Useful stuff - thanks for arranging this!

No problem. I saw something that apparently hadn't been researched and might be needed sooner rather than later and decided I would take care of it.

I've now done a video of the cap replacement with a few tips in the process in my latest video I published this morning...

https://youtu.be/u3jj1vyEufc

g883j7-2.png
Midi Modules: MT-32 (OLD), MT-200, MT-90, SD-20

Reply 5 of 5, by brownk

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CrossBow777 wrote on 2019-02-22, 16:33:

No problem. I saw something that apparently hadn't been researched and might be needed sooner rather than later and decided I would take care of it.

I've now done a video of the cap replacement with a few tips in the process in my latest video I published this morning...

https://youtu.be/u3jj1vyEufc

Thanks a ton for uploading the video. It cleared some of my questions regarding recap.

Plus, I'll add what I've found while recapping my unit. When I opened mine, I saw C40, and C41 (470uF/16V) bulged and they appeared to be input filters in MT-32 service manual. So I picked 470uF/35V instead. I'll add my capacitor replacement map below.

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