MC-505 stuck buttons

[evilpants]

Hi everyone. New guy here - I'm a long-time user of (exclusively!) Roland gear, but have spent years with no gear at all.

I just bought a JP-8000 and MC-505 from ebay, and I am absolutely in love with them.

The MC-505 has a problem. When you tap 'realtime erase', you can use the wheel or dec/inc buttons to change the exact thing you want to erase - notes, tempo, portamento, everything.

But on this unit, no matter what I select, it quickly jumps and changes back to "porta-t" on the display. Something is getting stuck, and it's impossible to change it.

I've made a shaky short video of it - https://www.youtube.com/watch?v=vJ8AJuUfCVU - it makes it pretty clear.

I suspect this is maybe a dirty contact, loose connection etc. The problem also appears when using the arp - I can't remember exactly, but when going through arp settings, it jumps to an EFX setting.

I'm not afraid to get my hands dirty - when I bought the JP-8000 I had a "memory damaged" error, and thanks to Roland Clan, I was able to open it up and replace the battery. I was confident doing it cos someone on Youtube had filmed every step of the process - including the hardest bit, unscrewing the unit. If you don't know the unit intimately, you can run into trouble unscrewing things.

None of the Youtube videos showing MC-505 repair actually show how to take it apart safely.

Can anyone advise me? Looking at the video, does this look fixable? Fixable by a confident amateur? Or does it need to be done by a proper person?

I'm in London, UK, and I'm happy to pay someone professional to do it. I've contacted the ebay seller to see if I can come to a deal on repair price. If I can do it myself, I won't charge the guy obviously, so if you guys can give me some advice, I'd appreciate it :-)

Thanks so much - and thanks to Roland Clan for helping me fix what seemed to be a completely broken JP-8000 when it arrived!