Groundhog needs help

[Occupant]

Anyone here familiar with the inner workings of Garretts legendary Groundhog? Mine is from 1978, the 'Pushbutton' model. Don't laugh. It will hold it's own with more modern machines and a descendant is still in production as the Gold Scorpion, but with surface mount components. My Hog has been working just fine until the other day and now it won't stay 'tuned'. The threshold, once set, fades away as soon as the tune button is released. Works fine in AutoTune with the handle button pressed, but fades upon release.

There is a 'daughter' card circuit board that I think is the 'tune' circuit. Am I on the right track here? As the capacitors are now 33 years old, is it time to re-cap the Hog? I've checked all the easy stuff, batteries, cleaned connections and DeOxit cleaned and lubed the controls, etc. Now it looks like time to un-solder and test components. Guidance and most suggestions appreciated.
Thanks all.
Roger

 

[newbiehunter]

Send it in to Garrett, they will fix it up, tune it up, polish it up and send it back in short order and not kill you on the price to do so.

 

[metalhead]

I have one o'those old Coin Hunters. Man, I don't know anything about the inner workings. Like newbie said, just send it to Garrett's for an overhaul.
Hey, you might wanna ask over on the analog forum. Lotsa knowledgeable folks there.
Best of luck to ya! Happy Hunting!

 

[Occupant]

Thanks for the suggestions. Looks like it will have to go to Garrett. That circuit board and caps seem to be the problem, but the board was epoxy dipped after assembly and I would have to wreck the board to get the caps off. Oh well.