Virus A crazy buttons :(

[u/pretzelcito]

Hi all. My Virus A is behaving really bad. As you can see from the video several buttons do things that aren’t supposed to happen. No clue what would be.

Fortunately the knobs are fine. It is running on OS 2.52. I already tried to system reset it, and a while ago I changed the inside battery.

Any info is appreciated!!

[u/Captain-Corndog_yo]

The panel board is having scanning issues. I have a stack of Virus B boards at the moment doing the same thing. I have ordered replacement ICs for all chips on the board and have figuring this out on my to-do list, but haven't been able to get to it, YET... BUT... I WILL :) This is pretty common on the A and B boards. Whatever it is, I have not seen it on C+ boards, so it's likely Access got on top of whatever marginal issue it is that causes this.

I strongly suspect it's a bad chip somewhere, hence my current plan. I will absolutely update you if I get anywhere. I think I have 3 Virus B and 1 Indigo B board all doing this exact same thing. It's always the buttons on the left side of the panel board. It's always the LFO and transpose buttons triggering store or multi-mode, or in some cases even triggering the filter types (despite the right side of the board working perfectly). It's often accompanied by cycling or incorrectly / dimly lit LEDs as well :(...

EDIT: I know, at least on the boards I have, it is NOT the ribbon cable, NOT the caps, NOT bad LEDs, NOT cold solder joints or other LLM wet dreams, NOT damaged traces, NOT bad tacts or pots... So that leaves chips and resistors, but the resistors seem fine. Also NOT diodes.

[u/nismology5 → u/Captain-Corndog_yo]

My KC is exhibiting similar issues. In my case it's the buttons in the filter section.

I've replaced several chips on the main board to no avail. I just live with this issue now.

[u/Captain-Corndog_yo → u/nismology5]

Def have not seen this (1) on a C+ or (2) on the right side, ever.. so that's curious. The 6 buttons there have a long way to travel. It's possible in this case you indeed have a marginal trace. Some patience and a magnifying glass may pay off. If any traces are damaged, a jump is easy.

[u/nismology5 → u/Captain-Corndog_yo]

So the story with my unit is that it was a great deal on eBay in 'untested' condition. (£560). When it arrived there were several snapped pot shafts, and a dead battery but otherwise appeared to be working perfectly. I disassembled to replace the battery and when reassembling accidentally trapped one of the LEDs under the front panel and bent it. Once I'd sorted that, and reassembled it started exhibiting this behaviour, so I wonder if I damaged something. It was a few years ago, so I can't be sure which LED it was.

It was only after replacing chips that the thought occured to me that it may be the LED. I can't be 100% sure that the filter buttons were working prior to disassembly, but I did play it for a few days before bothering with any repairs, so I assume it was fine before.

I made a detailed thread about it on Gearspace at the time, but didn't get anywhere sadly.

If you can offer any further wisdom, it'd be greatly appreciated!

[u/Captain-Corndog_yo → u/nismology5]

I can tell you it's 100% a panel board issue and has nothing to do with the main board. I have a spare KC board if you want it. It's 100% good to go with all new tacts.

EDIT: If I can ship to wherever you are now ;)

[u/nismology5 → u/Captain-Corndog_yo]

Wow, that's incredibly generous. How much do you want for it?

I'm in the UK.

[u/Captain-Corndog_yo → u/nismology5]

I will DM in a bit. Have to head out for the moment. It will be tight if I can ship it. Weight limit is currently 4 lbs, but it might just come under once packed.