Hi George, good morning, Im sorry to hear that.
Usually this is caused by a bad switch or failed wire connection on the vg-99.
You would need to open that up and check the wires to the switches.
This will require soldering to fix. So you will need experience in that feild or likely you will cause further damage :-(
I know this as once about 30 years ago I attempted this kind of thing with no experience and it wasn't a good lol.
Fortunately I have had mil spec soldering experience since then ;-)
I will help you though if you feel you can do this. If not, you would do well to bringing this to a guitar shop for repair.
They should know exactly what to do, it is an easy fix for an experienced technician Also not an expensive one either ;-)
In any case, I will stick with you until this is complete.
Please rate my service kindly.
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Thank you and have a great day George!