CZ-5 problem. Bad coil wire?

[The Buzzard King]

I got a problem with my CZ-5, and I'm hoping for some quick help here.
I bought it used last year, and it's worked PERFECTLY till today.
But I did notice it acting kind of strange, (LOTS of falsing), the other day when I had it out.

Here's the problem.
As soon as I turn the detector on, it immediately starts doing the "overload signal", and will not stop.
The only thing that will stop the overload signal, is to turn it off, or turn the sensitivity knob to the "battery check" mode. (which sound normal when I do it).
BUT, it ONLY seems to be "acting up" when the coil is plugged in.
If I remove the coil, the detector housing seems to be normal. (no noise, battery-check works fine, etc.)
I removed the components from the housing, to give them a visual inspection, and a good cleaning with "dust-off", and everything seems fine. (of course, I'm no expert though).
So, can a coil wire gone bad, make the detector go crazy, and make it have a continuous overload signal?
I know when the coil wire on my 1280 went bad, it was making wacky sounds.
And I'll admit I'm guilty of occasionally using the coil as a weed-wacker.
I only have the one 8' spider coil, and I don't know anyone near me with another coil that fits, so I can't do a test.
Any advice?
Thanks in advance.

 

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[Sky Pilot]

Buzzard King, Skypilot here! The coil wire can definitely short out and cause those symptoms, especially if the short is between the transmit and shield circuits. Has the unit sat or been stored for a particular time? If so, one of the potentiometers, (switchs), could have some corrosion on the wipers, and you may not necessarily notice the problem until the coil is plugged in, which completes the circuit. If that MAY be the problem, a drop or two of non conductive electronic lube may fix it right up. Simply remove the switch knobs, and place the oil, ( In The States it comes in a small tube with a very fine pointed end), at the base of the switch stem and work the switch between both extremes, (i.e; from one stop to the other), for several minutes. You will notice a slight drag of friction at first, then it will gradually loosen up. Other than that, I'm sure you have already removed and cleaned the coil bottom and the coil cover, if you use one. Sometimes very small pieces of of mineralised dust or rust can build up under the cover, and give a falsing of signals. One simple check is to trace the coil cable's cover from one end to the other, feeling very closely for a breach in the outer insulation, which may allow moisture to compromise the integrity of the circuit. Small thorns may do this as well as, (of course), severe angles of the cable may damage wires, after awhile. The coil wire does not have slack at the head end, I presume? That also will cause falsing. Sorry to be redundant, only trying to cover the bases. If you water hunt, then the coil may have developed a small leak, and the same will result. The only course of action if all this checks out, is to use a meter to test for continuity between the coil wires, and make sure that no more than two share the same circuit. Also, you want to check for loose or corroded battery contacts, as well as the pins and receptacles on the coil connector itself for a dull green patina, if so simply clean them and all will be well. Hope this helps! Please, keep us informed! Regards, Richard

 

[The Buzzard King]

Skypilot, thanks for the reply.
Yeah, I'm kind of assuming that I just beat the coil wire to death, right where it comes out of the coil.
It would be typical for me.
I'm always hunting in the woods, and places with tough, sometimes thorny undergrowths.
I usually need a machete half the time.
Time to start looking for a new coil.
Thanks.

 

[Sky Pilot]

No trouble at all, Buzzard King. It really stinks that you must get a new coil, I really had hopes it was serviceable. Well, thank you for the update! If I can ever be of service, you have only to ask. Great hunting and good luck! Regards, Richard

 

[TomNWMI]

Did you check the spring at the control box connector?

If the coiled relief spring works it's way in to far it will short out the connection causing noise. Simply give it a gentle tug to see if you can pull it out of the connector about a 1/4"

Just may do the trick.

Tom

 

[Dixie Digger]

i had the same prob with a cz5 i had on a trip to Fl.just went to Walmart and bought a $8 soldering gun and strip & re solder wires at connector.be sure and wright down color of wire to pin before you un solder . easy fix!

 

[Streak!]

it may be an easy fix....and it may not be...

Those coil connectors have a long history of failure.....especially if they are hipmounted. Actually...lots of coil wires cant take the stress of hipmounting very well, so it isnt exclusively a Fisher problem.
I'd take the thimbal off the end that plugs into the box, and have a good look at it. If that is where the problem is....then its a relatively easy fix. If its at the other end....then you'll likely need a replacement coil. Its almost certainly not a "short", but rather an open. Lots of times you can verify this before opening things up by careful manipulation of the coil wire along its length, (with the machine turned on) to see if you can make the problem come and go. Hope this helps a bit. Streak!

 

[supertraq]

Old post want to confirm i just had the same problem,turn unit on and it would make the overload sound continuosly..It was a lose wire at the coil connector at the box,little solider and a o.k..heads up to all.

 

[LuckyLarry]

Without checking it personally, it sounds like the two search winding have been loosened from the interior of the housing after being banged against rocks, sticks, trees, or other hard items. When doing this the two various different (stacked, single, or planar) windings can be misaligned with each other or warped and create a +/- overload that causes an imbalanced signal. Even a single wire PI can have a somewhat similar problem if the foam cushion has been dislodged in some way. The results would be an imbalanced, unexpected, steady, or undependable signal. This imbalanced signal will create "noise" (AKA "interference") which will result in creating a sound (a tone) in the speakers because the field pattern has been disrupted or interrupted. This of course causes a false signal, and the coil casing must be opened to repair the thing. I've encountered this before and also run into complete disconnections of the foam encasements which cause the whole inside package to shift one way, and then another. Some coil (windings) also have a small circuit board that could have been damaged. Plug the coil into the control box and tilt and shake the search coil in an area where there is no metal nearby that would interfere with what you are doing. If there is any change in audio when doing this, then you in all likelihood have a dislodged winding inside the search coil housing. if not, then there is most likely a problem with your lead (the cable), or its connectors. Hope this helps.