need help with drive, only 2 of 4 have a drive sign returned.
changed tl494c, replaced q5.
some help would be welcome. despite changing the 494c i still can not get drive on 2 of them. i dont have drive at both pins of the ic, only one.
changed tl494c, replaced q5.
some help would be welcome. despite changing the 494c i still can not get drive on 2 of them. i dont have drive at both pins of the ic, only one.
Attachments
Pins 8 and 11 of the 494 are tied together and should have B+ voltage on them.It would be unusually for this to happen.
Check to see if Q26 and Q27-2N4403 have drive on the base. If yes one of the drivers is bad,or a trace to the gates or gate resistor is open. If no follow trace back to the PWM card.
Check to see if Q26 and Q27-2N4403 have drive on the base. If yes one of the drivers is bad,or a trace to the gates or gate resistor is open. If no follow trace back to the PWM card.
Correc, i dont understand it.
pin 8 13.08vdc
pin 13 4.867
gate resistors good.
no drive at q29-q28
q27 2n4403 pnp is good.
dp5 good.
so ill test the driver card pin coming out to the gates of q29-q28.
pin 8 13.08vdc
pin 13 4.867
gate resistors good.
no drive at q29-q28
q27 2n4403 pnp is good.
dp5 good.
so ill test the driver card pin coming out to the gates of q29-q28.
Drive was working i meant to say.
Installed new 3205 transistors.
Amplifier is still in a protection state.
If its still like the 300.4 then lifting the protection resistors r33,r34,r88,r89? should narrow it down.
Installed new 3205 transistors.
Amplifier is still in a protection state.
If its still like the 300.4 then lifting the protection resistors r33,r34,r88,r89? should narrow it down.
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ok so.super strange. if i apply the center leg of q24 the 13.38vdc the amplifier goes into protection. unhook that one mosfet and the amplifier runs on the three.
