Did you check those IC DC voltages ?
You may want to see if you can find a data sheet.
Any MFG markings on it ? The OEM is probably 612303-1 (?)
You also have the NTG / ECG numbers. There was a backwards ECG disc
it could list every sub. Maybe its out there still. With that you can find
the REAL OEM for the chip & data sheet.
BTW I probably have a C-5 training manual. It would cost apx a 12 pack of
beer via PayPal PM if interested but try those voltages first.
73 Zeno
LFOD !