MCS2000 volume control not working

[dacndar]

Hi All,

I recently purchased a used MCS2000 model III control head off eBay to replace one that had died. The new one seemed to be working fine except there was no output from the speaker when using a remote control head kit. After looking closely at the control head, I discovered that it was configured for handset operation and not speaker operation. There is a 0 ohm jumper in one position or the other depending on how you want it to work. Anyway, I swapped the jumpers and the speaker now works. But then I notice the volume control on the control head doesn't work. So I troubleshoot it and confirm that the voltage on the wiper of the pot is changing when I rotate the pot. I discovered that if I rotate the pot and then power cycle, the volume level will correspond to the new position of the pot. It appears that the a/d converter is not reading the pot continuously but only at power on. This makes me suspicious that there is something in the programming that was set to make this head work different because of a handset. But I cannot find anything in the CPS that would affect this. Anyone have an idea?

Thanks,

Ken
K6DND

[Code3]

Check the part number on the control head. You should find that it is meant for rear head operation in a dual head configuration. In this setup the rear speaker volume is controlled from a pot on the speaker itself with an internal amp. The volume control on the head is disabled.

[skkeeter]

The Head will actually say "Rear Control Head" on it if it is a rear head. The part number is HCN1120A. If you bought it on June 18th, it is a rear control head. I missed bidding on it...

Skkeet

[dacndar]

Thanks Code3 and Skkeeter! You were right, it is an HCN1120A although I don't see anything other than the part number to indicate that it is a rear control head. I believe I bought this from the same guy that was selling the one on June 18th, I bought mine a week earlier. Well it does work and for my uses I can deal with it. I just cycle power every time I need to make a volume change. Model III control heads being sold separately have been few and far between. It took a long time to find this one. I assume that there is no way to change its functionality in the field or you would have mentioned it. Thanks again guys!

K6DND

[Code3]

This is speculation on my part, but I belive the problem is that the firmware loaded in rear control heads does not allow the operational volume adjustment.