White's Coinmaster 2000 D Series 3 schemetic or help

[HRife]

I have a White's 2000 D Series 3 detector I wish to restore to working condition. Does anyone have a good schemetic? The problem is a constant tone from speaker and no change in tone when metal is passed beneath the search coil. Thanks in advance.

[Tibuck19]

Can anyone offer insight on the coin master 2000 ? Clearly its a vintage analog detect, how does it compare to the TGSL-EDU Or the IDX PRO ? seeing how I have two coils that would work for it, would it be worth while, Perhaps modernize it in some way or another, perhaps design a sleeker 3d printed case.