Gold Bug problem

Evenin all. Got a problem with my Bug pro- in all metal I have a really unstable threshold. Anything over a gain of about 10 and the thing goes nuts, falsing like a bastard. Ground phase numbers ( the big central number ) are all over the show. If you touch the coil connection where it plugs into the control box it overloads. Disconnect the coil lead from the box and things improve slightly but the threshold is still really unstable.

In disc its not as bad but again the numbers bounce.

Any suggestions? Or anyone wanna buy it?

Hello,

Sounds like a write off on the control box to me, First thing I would do is resolder the connectors where the coil wires come in. Did it get wet? Is there visible corrosion on any of the solder joints on the back of the board? as in white looking powder or anything, or any “cracks” in the solder?

I’d buy it for parts if the price was right.

Hi Overdog
Don’t mean to sound rude but was this gold bug pro bought from a reputable dealer as there are some amazing looking knock offs available from China that do some crazy stuff.( I almost bought one before twigging where it was coming from) There are some very interesting you tube clips of these gold bug fos doing some crazy stuff like detecting leaves sticks and acorns ( like we don’t dig enough crap LOL )

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None taken buddy- its a good question! Bought it off a forum member, no reason to suspect anything dodgy. Got the El Paso sticker and the the holographic QC tag in the battery compartment. Even shows the version number if you hold the power button down on start up. Circuit board is probably rooted sadly.

Sadly it could be a clone, they have the same stickers and so on.

I just tested one of my GBP’s and with no coil its dead silent, so it’s looking like a board fault.

God dammit. Oh well, good excuse to get myself a Gold Kruzer or a Nox I suppose. From a recognised dealer this time.

sometimes such things are a simple fix if you are tech savvy , to me it does sound like a dry or broken contact or corrosion issue or even a rouge bit of metal like a rust flake that has been drawn into the control box by the speaker magnet , but if you are not good with striping and rebuilding items like this dont even try , there are often videos showing repairs ect on youtube that are worth the time before attempting such repairs as they can help avoid common mistakes that result in more damage ,also be aware of new things on yourself like a new phone as detectors can be easily upset by emf , things like high tension wires over head and electric fences cause similar falsing

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Hi thatguy- I don’t think its emf as it still goes nuts with just the control box powered up, no coil connected. Ive had it apart and cant see any dry joint or corrosion, waiting to hear back from Puikaki Supply to see if they can do anything with it.

ok have looked at vid and obviously you have opened it up , from the vid the soldier join closest to the bottom right of the display dose not look flash on the vid , i also dont like the look of the white on the board around quite a few of the soldier joins , if that is corroded lead it may be the issue , but be aware im only guessing and looking at an image on a screen

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also look at the chip sets to look for signs of them heating up like discoloration of the plastic they are encased in or distortion of the surface , if they have cooked its over sorry

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Ill resolder at work tomorrow- chipsets look ok- Im wondering whether its a problem with the potentiometer.

Isopropyl alcohol should clean the board yes?

iso is probably ok but avoid the screen as it may dissolve the plastic and wreck it

Copy that. Ill give it a nudge and see how I go. Thanks for the help!

even a dry hard toothbrush should move lead corrosion just be careful around components

Will do- theres a lot of delicate stuff in there!

normally most of the soldiering is on the back of the board with the tracks which appears to be the face up side in the vid

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By all means use the alcohol but AVOID GOING NEAR THE SCREEN, and reflow the solder on every joint you’re confident in doing, even add a bit more. Cotton tips with alcohol is best, I wouldn’t use a toothbrush. You won’t need to worry about corrosion on solder joints as you’re going to melt the solder on them to reflow it which will resolve that.

The way you mentioned when you push on the coil plug it overloads to me points to the issue being the coil wire plugs female end in the control box or its solder joints.

The reason I didn’t want to buy it off you was because you said it’s never run as stable as your other one. I did significant research into fakes as I thought I bought two of them from a shop in Oz, turns out mine were real. Fakes have bad coils and you can’t crank the gain right up, they go crazy due to their badly wound coils.

If it is real its worth fixing and I think doing what I’ve said has a high chance of fixing it.

Put up a couple of good photos of the front and back of the board.

I doubt it’s a pot issue.

A still bit of metal stuck to a speaker magnet in there wouldn’t set the detector off, the control box is full of bits of metal, it would need to be near the coil wires and be moving.

EMI is terribly unlikely without a coil connected as a receiver but easily ruled out by doing it elsewhere.