I noticed if I probe the negative input of the op amp next to it eventually the rail to rail oscillation comes back.
Have you replaced the left 5534?
Have you tried heating/cooling that area of the board to see if it makes a difference?
Have you tried heating/cooling that area of the board to see if it makes a difference?
I replaced both NE5534’s at the same time from Mouser. I’ve blown compressed air on it and didn’t make a difference.
If you push on various parts of the board in that area (with a non-conductive probe), dies that make a difference?
For those who don't know, the canned air is a refrigerant and if you invert the can, it will dispense liquid and freeze anything that the liquid touches.
For those who don't know, the canned air is a refrigerant and if you invert the can, it will dispense liquid and freeze anything that the liquid touches.
I twisted/pulled on the indicators and other parts and nothing happens. I noticed if I remove power from the amp when it stops oscillating and power it back up it oscillates for a few seconds then doesn’t.
Does LED400 remain on?
What does the signal look like on the output of the emitter follower pair of transistors that drive the optocouplers when you have rail-rail oscillation and after you lose it?
What does the signal look like on the output of the emitter follower pair of transistors that drive the optocouplers when you have rail-rail oscillation and after you lose it?
UPDATE: The amp is working. Apparently this amp has a regulated powersupply and that’s why the rail to rail looks like that over 12 volts. I used another set of RCA’s installed in vehicle and has been playing fine. Ill watch it to make sure but never seen a regulated powersupply that kicked in at 12 volts.