Korg M50 Freezing -- Which Capacitors Need Replacing?

[jpglyde]

I have a Korg M50 on the bench which freezes occasionally (no key, button or touchscreen response). In (many) other forums I've read that it needs a software update and there are two capacitors which need replacing. I updated the software to no avail. I just can't seem to find any info about which two capacitors need to be replaced. Has anyone heard of this? Can someone tell me which caps to replace? I'm trying to avoid having to send this thing off somewhere.

Thanks!

[Enzo]

Two caps? I haven't a clue.

I might explore the solder under such things as voltage regulators.

I would certainly get out my wooden chopstick and push on various components on the board looking for sensitivities. And just flex the circuit board in general.

[Jazz P Bass]

I just finished a Korg M50 repair.
I cannot say what your issue is, but the one I had the output would quit after about 2 minutes.
Along with that I noticed the tap tempo would stop.
I ended up resoldering the main cpu board.
That fixed it.
There are a lot of surface mount caps on that board.
The soldering did indeed look thin on them.
There is a 3 pin regulator that also looked soldered bad.
Unfortunately I do not know exactly which component (s) where to blame.
While I was in there (after it was running correctly) I went at the power supply/ I-O board with a solder reflow.

[J M Fahey]

In (many) other forums I've read that it needs a software update and there are two capacitors which need replacing.

Ok, which ones do they say need replacement?

Unfortunately, saying (while trying to look informed or important) "some thingie inside is bad" does not exactly help much.

[Enzo]

We have no idea the original source of the two caps idea. Might be true, who knows. But having been on the internet a while, it has happened to me. I'll make up an illustration. SOmeone asks why their SMPS won;t run, and I suggest a few things, and I might say "it could be as simple as a couple of caps." SOmeone reads that, goes elsewhere, encounters someone with a similar problem and says, "Enzo says it is a couple of caps." I didn't really, but then there it is. I have had a couple people thank me for some advice I gave on TalkBass forum. Problem is I have never posted anything there.


I know a guy, who knows a guy, who met someone, who used to know a guy.... and the message is garbled. That is how urban legends are born.

[jpglyde]

It was mostly consumer/user type forums so no one really knew which two capacitors it was. Many folks talked like it was a common problem. I was hoping some of you have seen or heard of the issue and could tell me the specifics. If you want to browse it for yourself, here are a couple examples:

Korg Forums :: View topic - KORG M50 FREEZING?!?! How can I fix this?!

Korg Forums :: View topic - M50 freeze while playing (note on forever, no button works)

[Jazz P Bass]

Do you have a soldering iron?

[jpglyde]

Do you have a soldering iron?

Yes, several. And surface mount soldering is not a problem. I am, indeed, a full time music electronics service technician.

[Jazz P Bass]

Take a good look at the main board.
I think you will see what I saw.
Really thin solder.

[jpglyde]

Yeah, you're right. It looks like some of those surface mount caps are just sitting on top of the pads.

Anyway, I did a reflow on everything I could reach with my fine tip. It hasn't frozen again in 3 days so I'm going to call it fixed and send it out of here.

Thanks