Roland Boss RC-20XL Loop Station Problem, Please Help

[bungusbeefcake]

Hi guys,

This is my first time posting. I couldn't find any fixes to my issue. Basically I have the Boss RC-20XL loop station and it went weird on me about 6 months ago. It started constantly flashing all the LED's as soon as I powered it up. I tried 3 different power supplies (all Boss) and I also tried battery power with the same result. It eventually stopped flashing all the LED's and just the power LED illuminated. I can press all the buttons but nothing happens. Nothing happens when I hold them down too, nothing illuminates or anything. Eventually after about 2-3 minutes of being on (with a power supply) the power  LED begins to fade and dies out, then a sound is heard through whatever amp is connected.

I have taken the unit apart but cannot see any scorch marks or anything so I have no idea whats wrong with it. I have taken pics of both sides of each of the circuit boards so feel free to have a look, maybe I missed something. I have also recorded a video, using both battery and mains power, showing the issue which can be found below.

I would really appreciate any help anyone could give me.

Thanks,

Regards,

Bungus

Images:
Upper Circuit Board - Top


Upper Circuit Board - Bottom


Lower Circuit Board - Top


Lower Circuit Board - Bottom


Video:

For some reason its saying its invalid, so here's the URL
http://youtu.be/58kP4RQptJM

[deadastronaut]

rather than start anew thread...

i just bought a ''non working'' boss rc-20xl for £20.00 off ebay as a punt...

and within 20 mins of getting it  i have it working.  YAY!!!!...well worth the punt.

note : this fix messes up the guide/drum sound...no idea why, but it gets your looper working again

1. Start by selecting Phrase 1.

(if the 'REVERSE' or 'AUTO START' are lit press them off.)

2. Select 'INST & MIC' by pressing 'MODE'

3. Hold down 'EXIT' and 'AUTO START' together - at the same time, this should light up the green LED for 'LOOP PHASE'

4. Hold down 'WRITE' and 'EXIT' together
then hold 'WRITE' on its own
then 'WRITE' and 'EXIT' together again...as if you were clearing a phrase.

they should light up in red and flash, if not try a combo of section 4.

5. Repeat on all Phrases 1 - 11.


basically you are erasing all the memory, the one iv'e fixed had all memories full and the tempo was ridiculously fast

on all loops which kinda locked it up......anyway..

might be handy for others..

now i'm off to loop my head off..

[bungusbeefcake]

rather than start anew thread...

i just bought a ''non working'' boss rc-20xl for £20.00 off ebay as a punt...

and within 20 mins of getting it  i have it working.  YAY!!!!...well worth the punt.

note : this fix messes up the guide/drum sound...no idea why, but it gets your looper working again

1. Start by selecting Phrase 1.

(if the 'REVERSE' or 'AUTO START' are lit press them off.)

2. Select 'INST & MIC' by pressing 'MODE'

3. Hold down 'EXIT' and 'AUTO START' together - at the same time, this should light up the green LED for 'LOOP PHASE'

4. Hold down 'WRITE' and 'EXIT' together
then hold 'WRITE' on its own
then 'WRITE' and 'EXIT' together again...as if you were clearing a phrase.

they should light up in red and flash, if not try a combo of section 4.

5. Repeat on all Phrases 1 - 11.


basically you are erasing all the memory, the one iv'e fixed had all memories full and the tempo was ridiculously fast

on all loops which kinda locked it up......anyway..

might be handy for others..

now i'm off to loop my head off..

Ok, cool, thanks for the reply! I dont have the loop station with me in this country but I'll get it next week and I'll give this fix a try!!

Really appreciate you posting a possible fix and I'll let you know if it works for me.

Bungus

[deadastronaut]

no worries man..

hope you get it sorted.  


i have no idea why this would  mess the drum/guide sound up...but i'll look into that too ok.

[Digital Larry]

For the OP, (presuming that DA's suggestion doesn't help) it sounds like something is broken in the internal power supply circuitry.  I would look for test points for the various voltages and measure those.  That would help you narrow it down to a specific supply section.  Unfortunately, this board looks like it has miniature switching power supplies and those are not going to be straightforward to diagnose and fix without a scope and some idea what the circuit in use actually is.

On the photo:  Lower Circuit Board - Top

The supplies are around the little flat round things (inductors), caps and chips on the upper right hand edge of the board.  Look really closely in this area.  It's possible that one of the electrolytics has shorted.  You could try lifting one side of those caps and check for shorts.  I do have to advise serious caution though, this is all delicate stuff and trying to pull up one side of an SMT cap, unless you really know what you are doing, could pull pads off the PCB and then you're going to be mad at me for suggesting it.

[deadastronaut]

Wasn,t their a spam thread already...