Is pin 15 at 5v and pin 16 at 0v? They should be.
I think the 494 is defective. To try to confirm, connect a resistor 1k or higher between header pin 2 and ground. If the 494 side is still higher (especially if it's still over 2v), that would tend to indicate that it's the 494.
I think the 494 is defective. To try to confirm, connect a resistor 1k or higher between header pin 2 and ground. If the 494 side is still higher (especially if it's still over 2v), that would tend to indicate that it's the 494.
Is pin 15 at 5v and pin 16 at 0v? They should be. = they are.
To try to confirm, connect a resistor 1k or higher between header pin 2 and ground. = relay clicks in now, amp lives.
The 494 side is still higher (especially if it's still over 2v), that would tend to indicate that it's the 494. = with 1k resistor from header pin 2 and ground - pin 3 TL494 goes to about 0.2v
Header Pin 2 = 0.1v
SD at the IRS = 3.9v with the 1k resistor
To try to confirm, connect a resistor 1k or higher between header pin 2 and ground. = relay clicks in now, amp lives.
The 494 side is still higher (especially if it's still over 2v), that would tend to indicate that it's the 494. = with 1k resistor from header pin 2 and ground - pin 3 TL494 goes to about 0.2v
Header Pin 2 = 0.1v
SD at the IRS = 3.9v with the 1k resistor
Everything I see says that the 494 is defective. I'm assuming that there is no problem on the board like contamination or parts of the wrong value or out of tolerance.