This amp has FQP50N06's with 100 gate resistors..
Would the Z44,46's work as replacements?
And if so do i need to change the gate resistors?
Would the Z44,46's work as replacements?
And if so do i need to change the gate resistors?
Either should work with the 100 ohm resistors but you need to force the supply to full duty cycle (assuming that it has a regulated supply) and confirm that the FETs remain cool at idle.
Replaced power supply fets..
Amp still doesnt power up ..
Heres what i get on the 494
Pin 1:0.00
Pin 2:1.90
Pin 3:0.06
Pin 4:0.00
Pin 5:0.48
Pin 6:0.60
Pin 7:0.00
Pin 8:2.69
Pin 9:0.00
Pin 10:1.27
Pin 11:2.68
Pin 12:2.68
Pin 13:1.88
Pin 14:1.88
Pin 15:1.88
Pin 16:4.42
Amp still doesnt power up ..
Heres what i get on the 494
Pin 1:0.00
Pin 2:1.90
Pin 3:0.06
Pin 4:0.00
Pin 5:0.48
Pin 6:0.60
Pin 7:0.00
Pin 8:2.69
Pin 9:0.00
Pin 10:1.27
Pin 11:2.68
Pin 12:2.68
Pin 13:1.88
Pin 14:1.88
Pin 15:1.88
Pin 16:4.42
Pin #12 is Vcc it should have battery voltage.
Pin#13 is the output it should have battery voltage.
Look up the data sheet and see which pins are what.
Pin#13 is the output it should have battery voltage.
Look up the data sheet and see which pins are what.
I tracked it back to a 4458 IC
Heres the voltages i get on it..
Pin 1:1.43
Pin 2:1.91
Pin 3:0.81
Pin 4:0.00
Pin 5:6.82
Pin 6:12.55
Pin 7:1.42
Pin 8:13.72
Does this appear to be ok??
If so ill back track furhter
Heres the voltages i get on it..
Pin 1:1.43
Pin 2:1.91
Pin 3:0.81
Pin 4:0.00
Pin 5:6.82
Pin 6:12.55
Pin 7:1.42
Pin 8:13.72
Does this appear to be ok??
If so ill back track furhter
The 4558 isn't likely to be used to supply power to the power supply IC. It may drive a transistor that drives voltage to the PS IC but it won't drive it directly. The voltage is likely supplied via the collector of a PNP transistor.
Replaced that same problem only 2 volts on pin 8..
There are only 2 other transistors in that area A1015's
If i find 1 to be defective is there a good replacement for thoose?
Also there is a diode connected to pin 8 (ZD1) 1 side has 2 volts other side is 0.00 volts and 2 volts measured directly across it..
I that normal and i need to back track more?
There are only 2 other transistors in that area A1015's
If i find 1 to be defective is there a good replacement for thoose?
Also there is a diode connected to pin 8 (ZD1) 1 side has 2 volts other side is 0.00 volts and 2 volts measured directly across it..
I that normal and i need to back track more?
The middle leg of the BD140 connects to a 100 ohm resistor then goes to pins 8,11,12..
If i place one probe on pin 8 and the other probe on the middle leg of the BD140 i get 100 ohms on pin 8 ..
So im assuming that the BD140 is connected to pin 8
I get 13.89 volts on 1 side of the 100 ohm resistor but only 2.74 volts on the other side..
Could the 494 possibly be bad?
If i place one probe on pin 8 and the other probe on the middle leg of the BD140 i get 100 ohms on pin 8 ..
So im assuming that the BD140 is connected to pin 8
I get 13.89 volts on 1 side of the 100 ohm resistor but only 2.74 volts on the other side..
Could the 494 possibly be bad?
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