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My Roland Micro Cube RX died today

MrWalker

MrWalker

Apr 3, 2002
1,846
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58
Norway
#1
I have been fixing basses today, and have been plugging in and checking after my adjustments and such. It's been running on adapter for 2-3 days straight now. After i was done today, I turned it off while the rythm guide was running. Two hours later, I turned it on... and nothing happened. It's stone-cold. Won't start up on batteries nor adapter.
I was thinking maybe there's a fuse somewhere, but no.... no fuse can be located from the outside.

has anyone had a similar problem with any of the micro cubes? Is there anything I can do, or is it gone?

:help::help:
 
#2
Opened it and looked inside... found something that looks a little weird. Have included photos. To my untrained eye, this looks a capacitor melted down or exploded. Can anyone confirm this? I am guessing I need to get this little rascal swapped out.
 

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#3
One more.... I think the capacitor exploded when I turned off the power... the two wires going off the circuit board are going to the power inlet.

Is this hard to fix? I'm debating whether to bring it in and let the pros handle it and pay their $100, or put a soldering iron to it myself. I have done a bit of soldering in during my degree, but it's a few years ago, and the equipment we had was far superior to the amateur soldering iron I have now. hmmmmmmm :)
 

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#4
Sorry to bump an old thread, but I found this because while searching—I have the same amp with the same issue. It similarly has what appears to be a blown surface mount capacitor, or at least my circuit board looks the same as yours with the white goop. What did you do to fix it?
 
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#5
avocado said:
Sorry to bump an old thread, but I found this because while searching—I have the same amp with the same issue. It similarly has what appears to be a blown surface mount capacitor, or at least my circuit board looks the same as yours with the white goop. What did you do to fix it?
Click to expand...

The white goop is vibration prevention silicone... It's supposed to be there, an exploded cap looks, well, exploded... Failed caps I've seen look chubby and puffed out, 'leaky' caps seem to ooze a resin like substance...
In the picture the device mainly covered with silicon doesn't look like a cap, might be an inductor coil or mini transformer. Good luck !
 
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#6
I have owned my Roland RX for 6 years now. 3 years ago it too didn't want to power up. I flicked the power switch a few times and it came alive. It happened once or twice more the following week, but I haven't had any problem since and it's still going strong.
 
#7
Thanks all!

goran said:
I have owned my Roland RX for 6 years now. 3 years ago it too didn't want to power up. I flicked the power switch a few times and it came alive. It happened once or twice more the following week, but I haven't had any problem since and it's still going strong.
Click to expand...

Sure enough, this worked for mine, too, and the amp works great now. No need to threaten it with a soldering iron. If it keeps happening, I'll replace the power switch.
 
#9
It seems a dodgy power switch is the most common reason for the Micro Cube to "go dead". I just opened mine up and bridged the switch terminals with a screwdriver and it powered up. So I then rocked the switch back and forth a heap of times and mine has come good too. A nice, cheap, easy fix!
 
#10
That on/off powerswitch is a problem. Taking it apart reveals some design flaws that you can *maybe* resolve with some creative engineering, or simply remove it and solder in a replacement switch somehow. Or clean it as best you can and turn it on/off a hundred zillion times and leave it "on" and control power by unplugging the power cord.

I fixed my switch and the little thing worked fine, but I dropped a screwdriver inside when reassembling it and evidently shorted something. It won't power on (battery or powerplug) and I can't find any fuse or circuitbreaker gizmo anywhere. Your thoughts?
 
#11
joetho said:
That on/off powerswitch is a problem. Taking it apart reveals some design flaws that you can *maybe* resolve with some creative engineering, or simply remove it and solder in a replacement switch somehow. Or clean it as best you can and turn it on/off a hundred zillion times and leave it "on" and control power by unplugging the power cord.

I fixed my switch and the little thing worked fine, but I dropped a screwdriver inside when reassembling it and evidently shorted something. It won't power on (battery or powerplug) and I can't find any fuse or circuitbreaker gizmo anywhere. Your thoughts?
Click to expand...
My thoughts, you have created now unrepairable (economically) damage.
 
#13
agedhorse said:
My thoughts, you have created now unrepairable (economically) damage.
Click to expand...
Hmmm, methinks The Engineer could perhaps redefine his terms.

Anyway, I found a circuitboard fuse hidden in there (see pix) and soldered a couple of wires in its place. I will install a panel fuse accessible from outside, assuming i can find one at a car parts store. I would ike to put this thing back together this afternoon, and I would have soldered in a replacement but the days of BA Electronics or even a Radioshack that sells stuff like this... sigh.

Think like an engineer and look for hints. If you see something in a fuse-like place, check it out. If you freeze it and it starts working, look for a failed semiconductor. If it looks scorched, replace it. Get a good soldering rig and learn its eccentricities. Fix stuff.

We are on our own here, troops.

The "finished" product. Wires soldered in place of blown fuse.
20230601_144311.jpg


Original view.
20230601_100427.jpg


Another original view.
20230601_100410.jpg
 
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#14
If it works, you are darn lucky and ought to go out and but a lottery ticket.

(that's not how engineers think by the way).
 
#16
joetho said:
Hmmm, methinks The Engineer could perhaps redefine his terms.

Anyway, I found a circuitboard fuse hidden in there (see pix) and soldered a couple of wires in its place. I will install a panel fuse accessible from outside, assuming i can find one at a car parts store. I would ike to put this thing back together this afternoon, and I would have soldered in a replacement but the days of BA Electronics or even a Radioshack that sells stuff like this... sigh.

Think like an engineer and look for hints. If you see something in a fuse-like place, check it out. If you freeze it and it starts working, look for a failed semiconductor. If it looks scorched, replace it. Get a good soldering rig and learn its eccentricities. Fix stuff.

We are on our own here, troops.

The "finished" product. Wires soldered in place of blown fuse.
View attachment 5080808

Original view.
View attachment 5080809

Another original view.
View attachment 5080810
Click to expand...
It worked ...thanx buddy!!!
 

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