Yeah this is too hard, a very very slow and annoying process
Hot air probably would be helpful, but I don't own one, closest thing I have is a industrial heat gun, but that would screw up the board too easily if I'm not careful
Hot air probably would be helpful, but I don't own one, closest thing I have is a industrial heat gun, but that would screw up the board too easily if I'm not careful
That combined with the heating up 2 pins worked.
The amp does power on seemingly fine. Protect light shows for about 7 seconds, then powers up. I assume that is it's power up sequence.
Anything to test while they are removed?
The amp does power on seemingly fine. Protect light shows for about 7 seconds, then powers up. I assume that is it's power up sequence.
Anything to test while they are removed?
Drive a strong audio signal (50-100Hz) and look for drive on the gates of the output FETs. Black scope probe on the source leg, probe on the gate. Do you have a good signal on all of the output FETs?
The 4580D no longer is getting anything on the input (maybe some pulses, could be noise tho), previously the waveforms were odd, but it had signal.
Gonna try to see where the signal gets lost
Gonna try to see where the signal gets lost
Have you tried operating all of the pots and switches through their entire range with a signal source connected to see if you ever saw signal on the driver board?
Yeah, it was the master/slave switch
the in2+ (pin 5) is low voltage, but out2 (pin 7) is a strong sine wave
But out1 (pin 1) is weak, seems the same as in1+ (pin 3)
The chip got quite warm, didn't test with my probe but I'd say 30-40c
Still no gate drive
the in2+ (pin 5) is low voltage, but out2 (pin 7) is a strong sine wave
But out1 (pin 1) is weak, seems the same as in1+ (pin 3)
The chip got quite warm, didn't test with my probe but I'd say 30-40c
Still no gate drive
Testing the 4558Ds near the inputs, some randomly have a low output, but after the ones following it have a good output
But the furthest one from the RCAs has +15v on the out1. That can't be good
But the furthest one from the RCAs has +15v on the out1. That can't be good
Yeah, both react to the gain adjustment. I can basically turn the pin 7 into a square wave when gain is maxed out
According to the information I have, there is only a 1k/10k voltage divider between 7 and 3. There shouldn't be a great difference in the levels. Measuring the level on each pin with a multimeter on ACV, what do you have on each. Set the level so that you have the maximum unclipped signal on pin 7.
The IC could be defective. With supply voltage, there is no reason that pin 3 should be loading the signal that much.
What's the resistance between pin 7 and 3, no power applied?
What's the resistance between pin 7 and 3, no power applied?
It appears that this board could have the two sections of the IC reversed. Resistance pin 1 to pin 5?