CZ7a screaming for help!!

[Digger Dan]

Hi everyone,

I'm new here, though I've been metal detecting about 12 years when time permits. My problem is that my old reliable CZ7a is acting crazy and I can't figure out what is going on, so I'm hoping the mass of talent in this forum can offer some help.

My CZ7a is not the Pro version, but the one with the 12 AA batteries under the arm rest. I put new batteries in, made sure everything was clean and tight, and fired it up today for the first time this year, and it is really going nuts. When it is first turned on, it seems to be OK. But I can't ground balance it, and after it finds any metal in the ground it sounds like it wants to ID it properly, then I get a massively loud squeal that can only be stopped by turning off the unit. I tried all my coils with the same result. Since the only movable knob is the Ground Balance, I thought it might have corroded or just got dirty and that a cleaning might fix it. BUT I won't do anything until I get some feedback and ideas here.

Anyone have a similar problem that they were able to fix? Or am I looking at a trip to Fisher for an overhaul? Any help and replies greatly appreciated.

Thanks a lot
Digger Dan

[Bart@Big Boys Hobbies]

Sounds like a trip to Fisher. I would at least call them and explain situation.

[Sandman]

I was thinking it was more of a matter of cleaning out the coil cover till you said you tried all your coils. I think a trip to Fisher is due. It might be a broken solder joint.