My Christmas Miracle: piezo circuit board repaired

[ArcherRecording]

I'm excited to share this story of how I got my piezo preamp circuit board repaired in hopes that it might help others. Long story short, I've have a late 90s Parker Fly (SN 134119BMH) and the piezo pickup hasn't worked for years. Like many forum members I've been around the guitar world trying to find a fix. I had concluded that the circuit board could not be repaired and my only hope was to find a used one or go with the aftermarket work around preamp. I was determined to find an original preamp but wasn't having any luck.

Here's where the Christmas miracle happened.

My brother in law just retired from the DOD as an electrical engineer. As far as I know, he's never touched an electric guitar, let alone a Parker Fly. I talked him into having a look at the Parker circuit board. He researched the design and started talking way over my head about how the card was supposed to work. He concluded that it was a power supply issue. I'm going to attach his notes to this post because I want to make sure I get this right. The quick test to see if this might work for you is to measure the voltage on pin 5 of the LTC1044 chip. If you don't measure -9 volts (negative 9 volts) on pin 5, you need to replace the chip. I shipped the circuit board to him as he lives in another city. I got it back yesterday and wow, the piezo is now alive and well! Not only did he replace the chip, he sourced the replacement and installed an IC holding socket so if the chip goes bad again I can just just plug in a new one. And he sent me two extras.
I hope this helps someone.

[mmmguitar]

Beautiful! Much thanks to you and your brother in law, @ArcherRecording. If only more guitar components could be brought closer to mil-spec.