Sorry I meant member NZ0J.
Power supply should be set to 13.6Vdc @ 15A
Is this a standard VX-2200 or LTR model?
If LTR, check programming to make sure it's not corrupt, if corrupt do try reloading program to default settings.
Disconnect power, unsolder pin 3 of Q1009 (PA) from the board (this removes 13.6Vdc and disables the PA), reconnect and turn unit on. Does it reset power when you PTT?
If the unit does not reset power, when you PTT, Replace Q1009 (Need to know if its LTR, Standard, UHF, or VHF) example: VX-2200-D0 or G7, VX-2200-AD0H or AG7H
If the unit still resets power, might be your code plug / program or I'll have to look more into what the issue is, but it sounds like your PA has gone bad.