Sounds like the microswitch has gone. Seen a few posts about this over the years. Not a hard job to replace it yourself from what I understand.

Craig🙂

If the MCP does NOT light up when the wheel is rotated, the microswitch is bad.
If the MCP lights up when you rotate the wheel but the volume does not change, the microswitch is OK
and the optical reader is bad (I have a few NOS optos).

Martin

I have a replacement microswitch. It may just need the contacts cleaning though if this is the fault.

Chris.

Dillen wrote:

If the MCP does NOT light up when the wheel is rotated, the microswitch is bad.
If the MCP lights up when you rotate the wheel but the volume does not change, the microswitch is OK
and the optical reader is bad (I have a few NOS optos).

Martin

Oh thank you very much, the MCP does NOT light up when the wheel is rotated. Therefore I guess I'm needing the new microswitch then.

When coming to do that replacement, do I need to refer to the service manual I wonder? Or maybe you guys could talk me through what I need to do..

...if this job needs soldering or the use of any technical equipment I'm not able to do that & would be looking to send it off to someone in that case.

Thanks for your helpful assistance.

Medogsfat wrote:

I have a replacement microswitch. It may just need the contacts cleaning though if this is the fault.

Chris.

Hello Chris,

Many thanks for your help. According to advice given on this thread, it sounds like the microswitch is what I need (or maybe just cleaning as you say) as the MCP doesnt light up on moving the dial.

Is the microswitch an easy job for someone with no technical ability at all, like me..? Would I need to get hold of the service manual, or perform any soldering to replace this switch?

And if you have a microswitch or sale, please let me have the details.

If you do these types of repairs yourself (i remember talking to you about re-covering Penta frets i think!) please let me know if I could send the MCP up to you for attention.

Many thanks for your help.

Michael

Are the other functions of the MCP working ?

Martin

Dillen wrote:

Are the other functions of the MCP working ?

Martin

Hi Martin,

Yes, all other functions seem to be working just fine.

Michael

I got an almost free MCP5500 (aluminium with ugly spots of some kind of glue and broken hinges but otherwise great condition) some weeks ago, with original box.

I have opened it and tried to clean (first with contact cleaner, later with fine sand-paper) the microswitch but it's still working randomly. Sometimes it works flawlessly and sometimes it doesn't work at all (I have to rotate the dial up and down until it starts working).

The switch has a socketed cable so if you can get a replacement, it's very easy to replace. Here is a close-up of the mechanism:

lausvi wrote:

I got an almost free MCP5500 (aluminium with ugly spots of some kind of glue and broken hinges but otherwise great condition) some weeks ago, with original box.

I have opened it and tried to clean (first with contact cleaner, later with fine sand-paper) the microswitch but it's still working randomly. Sometimes it works flawlessly and sometimes it doesn't work at all (I have to rotate the dial up and down until it starts working).

The switch has a socketed cable so if you can get a replacement, it's very easy to replace. Here is a close-up of the mechanism:

Oh thanks for that Sir,

So its just a simple 'plug-out the old' and 'plug in the new' type situation?

well, if it's really as easy as that perhaps even I could do it😁 , so Chris or anyone else who may have a spare switch please could you leave details for me.

Many thanks for all the advice

Michael