While I was at it, I took apart everything and I cleansed it all with KH-7 (those living in Spain will know!) and distilled water.

Here is a "family pic" of all the parts that were once covered with a yellowish-brown layer of nicotine, now all cleaned up:

May the Dark Gods help me assembling this puzzle back...

did you find the data sheet? maybe youll be lucky and those taps will give the same output it needs from your inputs. datasheet will tell you for sure.

I've been looking for them but I haven't had any luck so far.
The unit comes with the original manual (in Japanese!) and doesn't seem to have any datasheet or schematics.
I found the English version online, but it's more of the same.
Is there a way to test this transformer? Like, solder the wire to the 230V pin and check with some tester?
I hate those 220 to 100 V converters, but I'd hate to burn this thing even more!

I'd do a test this way: hook up the unit transformer to a 100VAC source through one of those converters you hate so much, and measure the AC voltage between the "0" post and the "230" post. If it's 230V or close, then I'd say you're safe to try your mod. The reason being, a transformer with unused windings in its primary will also act as an autotransformer.

Thanks a lot for your pro tip!
I just finished assembling the unit. I'll give it a go tomorrow!

Apparently it dried enough to power on without throwing a fireworks show :p

I saw here Roland SC-88 repair what I think is a conclusive clue about these pins on the transformer.
In this example I suspect the SC-88 is meant for the US market, as the black wire is soldered on the pin labelled "120".

I'll check tomorrow as stamasd suggested.

It is of course your responsibility to check the service manuals yourself, but from what I have understood, they only have sold the device with one universal transformer and the localisation is done through different mains cord assembly and soldering the mains input to correct voltage tap on the transformer. So in my opinion, it is possible to change the mains voltage input just by using the 230V or 240V tap from the transformer without breaking it.

Note that I am not saying whether you should do it or not, I don't want to encourage people to fiddle with mains because it could be lethal if something goes wrong.

I don't know whether you should select 230V or 240V tap. In my country we had 220V until whole EU changed to 230V, so some very old places could have only 220V. Some other countries had 240V until it was changed to 230V, but some very old places could still have 240V. But on the average, in EU, I think it should be the 230V tap.

It is of course your responsibility to check the service manuals yourself, but from what I have understood, they only have sold the device with one universal transformer and the localisation is done through different mains cord assembly and soldering the mains input to correct voltage tap on the transformer. So in my opinion, it is possible to change the mains voltage input just by using the 230V or 240V tap from the transformer without breaking it.

Success!
My lack of experience is painfully visible on the (very) bad soldering job I did...
And I managed to overheat the 100V pin, which melted the plastic around it and it came out when I pulled on the wire.
But at least it's now working straight out of an outlet in good old 220V!

Note that I am not saying whether you should do it or not, I don't want to encourage people to fiddle with mains because it could be lethal if something goes wrong.

I fear my doings might prove way more lethal for the devices I poke than myself...

I don't know whether you should select 230V or 240V tap. In my country we had 220V until whole EU changed to 230V, so some very old places could have only 220V. Some other countries had 240V until it was changed to 230V, but some very old places could still have 240V. But on the average, in EU, I think it should be the 230V tap.

I have soldered it to 230V as a middle road between 220V and 240V.
I guessed the difference isn't high enough to be problematic and within tolerance.

Thank you all for your help and suggestions and advice, they are greatly appreciated, as always!

I actually found this page a while ago while researching the topic:

http://esher.ru/news/blog/899.html

A few years ago I bought one from a Japanese seller which had an universal PSU, so I guess there is a mod for this.

@PoulpSquad

Im planning to do the same operation on a SC-88 i recently acquired. I can't help but notice that you plugged the blue "neutral" cable on the "hot" connector which then goes to the main power line (230V). Any reason for that ? As far as i understand, this is a typical case of reversed polarity. You should be careful 😀

^ take a look at the units power plug and you'll see that even if the inside connections are reversed it doesn't make any difference as the chance of "correct polarity" remains 50% 🤣 🤣 🤣

I just ordered a Japanese SC-88Pro from an auction site, and I'm gonna need to convert it to 120ish US-style power. Anyone able to replace the photos that Tinypic deleted?

if its like the other units, just desolder the transformer tap from 100, solder new one from 120.

ChrisTOTG wrote on 2022-10-16, 05:56:

I just ordered a Japanese SC-88Pro from an auction site, and I'm gonna need to convert it to 120ish US-style power. Anyone able to replace the photos that Tinypic deleted?

Look here https://web.archive.org/web/20180106144118/ht … hp?f=46&t=47396
and here
[SOLVED] Fried/Grilled sc-88 pro