I am having trouble find out why I have no power on this thing.
The ps fets were replaced first and the outputs checked out ok.
Do the pwm chip go out on these often?
I have no leaking caps , already checked that.
The ps fets were replaced first and the outputs checked out ok.
Do the pwm chip go out on these often?
I have no leaking caps , already checked that.
Post the DC voltage on all of the pins of the TL494 driver IC.
(copy and paste this into your reply)
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:
(copy and paste this into your reply)
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:
dead 100dsm
That series of Fosgate amps used a daughter board as the power supply pwm oscilator & driver to the FETs. These were
most often the culprit. The boards have been out of production
and out of stock a number of years. At our service facility we were
never able to repair the daughter boards as it meant soldering to
a pad on a ceramic surface. Perhaps someone else had sucess.
Bear-k
That series of Fosgate amps used a daughter board as the power supply pwm oscilator & driver to the FETs. These were
most often the culprit. The boards have been out of production
and out of stock a number of years. At our service facility we were
never able to repair the daughter boards as it meant soldering to
a pad on a ceramic surface. Perhaps someone else had sucess.
Bear-k
I think this is the board he has:
http://www.bcae1.com/temp/img372rockforddriverboardpowersupplyold.jpg
http://www.bcae1.com/temp/img372rockforddriverboardpowersupplyold.jpg
I have no power on the tl594c at all
Pin 1: 0.00
Pin 2: 0.00
Pin 3: 0.90
Pin 4: 0.00
Pin 5: 0.00
Pin 6: 0.00
Pin 7: 0.00
Pin 8: 0.00
Pin 9: 0.00
Pin 10: 0.00
Pin 11: 0.00
Pin 12: 0.00
Pin 13: 0.00
Pin 14: 0.00
Pin 15: 0.00
Pin 16:0.010
Reflowed the solder on the vertical board , didn't help.
I have power up to the board then nothing to the ic.
Pin 1: 0.00
Pin 2: 0.00
Pin 3: 0.90
Pin 4: 0.00
Pin 5: 0.00
Pin 6: 0.00
Pin 7: 0.00
Pin 8: 0.00
Pin 9: 0.00
Pin 10: 0.00
Pin 11: 0.00
Pin 12: 0.00
Pin 13: 0.00
Pin 14: 0.00
Pin 15: 0.00
Pin 16:0.010
Reflowed the solder on the vertical board , didn't help.
I have power up to the board then nothing to the ic.
Ben, when you said you have power up to the board, were you talking about up to the vertical board, or did you mean the mainboard?
Remote voltage goes into pin 8 of the driver board (counting left to right, looking at the component side of the driver board), through a diode (4th black component from the left on the bottom row in the photo I posted) and then to pins 8, 11 and 12 of the 494. The voltage goes into the top terminal of the diode and exits from the bottom right terminal.
The diode is bad , power in no power out.
I have some A7 diodes from old punch 45hd boards will that work ?
I think the one that is on there is A7c maybe.
I have some A7 diodes from old punch 45hd boards will that work ?
I think the one that is on there is A7c maybe.
A7 is the correct part.
Remember to use a small fuse when powering it up in case there is another problem. Clamp the transistors to help protect them.
Remember to use a small fuse when powering it up in case there is another problem. Clamp the transistors to help protect them.
If the power supply FETs failed, the diode may have failed because there was too much current draw through it. They began using a larger diode in the newer models (IX series).
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