I've checked with a couple of local electronics repair places and they want more to look at the Amp than the Amp is worth. I've recently purchased a Blackstar HT Stage 60 for myself and was hoping to get the Crate fixed, as inexpensive as possible for my teenage son to use with his guitar. Thanks for the comments so far. I'm taking your suggestions into consideration.

 Hi Everyone, I have a Crate G130C Amp that I bought new in in the mid 90's. At some point I started having an issue with the Amp where the output sound would fade out. If it would cool down, it would temporarily start working again. I sent the Amp in to SLM Electronics / Crate, in St Louis, Missouri and they fixed the issue. It worked fine for many years but has developed the same problem again. As you probably know, they have went out of business. I took the circuit board out of the Amp and have replaced a few resistors that had split open from overheating,but that didn't fix the main problem. I recently found the paperwork that SLM Electronics sent me when they repaired the Amp before. It says that they had replaced a "Leaky Zener Diode for the low voltage power supply"  They unfortunately didn't put a part number for the Zener Diode on the invoice. I have ran across the schematics for this Amp but I can't tell where the Zener Diode is for the low voltage power supply. Could someone please help direct me to where the Zener Diode is located on the circuit board?