So the amp works fine, power LED lights, but after about 10 seconds, it fades out. Amp still operating fine.
Same routine if I power cycle the amp.
Will try to trace the drive out, but hoping for advice.
Same routine if I power cycle the amp.
Will try to trace the drive out, but hoping for advice.
So the amp works fine, power LED lights, but after about 10 seconds, it fades out. Amp still operating fine.
So is it just the LED fading out? Does the amp continue to have audio after the LED fades out?
Post pics of the board.
So is it just the LED fading out? Does the amp continue to have audio after the LED fades out?
Post pics of the board.
As the amp powers up does the Red LED light up then fade out as the Green LED lights up?
After the Green LED fades out, are both the Red and Green LED's not lit?
On the 13 header pins of the PWM card, measure the DC voltages and post. Pins 12 and 13 are the drives for the Green and Red LED's. I'm not sure of the orientation, but will check tomorrow.
After the Green LED fades out, are both the Red and Green LED's not lit?
On the 13 header pins of the PWM card, measure the DC voltages and post. Pins 12 and 13 are the drives for the Green and Red LED's. I'm not sure of the orientation, but will check tomorrow.
It's getting B+ drive from pin 12 of the PWM card. The 4401 that I assume should be grounding the cathode of the LED is not getting back to ground. I I jump the 4401 the LED lites up.
DO you know what the values of RP2 and RP5 should be?
DO you know what the values of RP2 and RP5 should be?
There is something going on now where the amp starts and runs with no remote applied. Amp section works fine, but remote is not controlling amp on/off. I believe remote is pin 11 of the pwm card thru zd1?
ZD1-5.1v zener. It's possible the zener has cracked, which is not uncommon.
RP87-0 ohm resistor may be open. This can be checked measuring ohms between Power and Speaker Grounds.
If the amp powers up without remote it possible that Q17-2N4401 is shorted emitter to collector. This is the alternate DC or Hi level Turn on switch.
RP87-0 ohm resistor may be open. This can be checked measuring ohms between Power and Speaker Grounds.
If the amp powers up without remote it possible that Q17-2N4401 is shorted emitter to collector. This is the alternate DC or Hi level Turn on switch.
Remote circuit is repaired but still have same issue of green led fading out after about 30 seconds. Amp is running fine while the green led goes away.
If I lift RP2 the green led works as it should.
Q18 and PC2 are ok.
LED has 1.9 volts across it when it is on and shuts off when it gets to 1.5 volts
If I lift RP2 the green led works as it should.
Q18 and PC2 are ok.
LED has 1.9 volts across it when it is on and shuts off when it gets to 1.5 volts
Also, it takes the amp about 7 seconds for the PS to start switching after remote is applied. That seems too long.
Does the Red Protection LED light initially or any other time? With the amp in a chassis If you briefly short an output do you see the Red LED light?
This is a weird problem, it shouldn't take 7 seconds for power up. Carefully inspect around the LED's and circuit. I recall seeing something similar, it's possible you have a cracked trace or bad solder joint.
Also, have you checked RP87- the 0 ohm resistor that ties speaker and power grounds. You will find it near the PWM card.
This is a weird problem, it shouldn't take 7 seconds for power up. Carefully inspect around the LED's and circuit. I recall seeing something similar, it's possible you have a cracked trace or bad solder joint.
Also, have you checked RP87- the 0 ohm resistor that ties speaker and power grounds. You will find it near the PWM card.
It was RP87. Which is a fusible link? It was open. When I jumped it out now everything works as it should. Thanks so much.
Yes, fusible link. With this amps, when you see strange symptoms such as this R87 is a usual suspect.
Spoke too soon.
Seems amp is releasing from mute too soon at start up and sending audio before the waveform has fully developed. Can you point me in the direction of the mute circuit components?
Seems amp is releasing from mute too soon at start up and sending audio before the waveform has fully developed. Can you point me in the direction of the mute circuit components?