Im working with this amp, all of the driver and power supply mosfets
transistors were shorted, so I cut out all the power supply mosfets legs and
desolder all driver transistors to scope the power supply signal, but there's was no signal at any of the power supply driver board pins.
12 volts are present at the remote pin of the driver board when remote is apply.
There are two tl494 chips on the driver board. Is it possible that both tl494 are bad?
transistors were shorted, so I cut out all the power supply mosfets legs and
desolder all driver transistors to scope the power supply signal, but there's was no signal at any of the power supply driver board pins.
12 volts are present at the remote pin of the driver board when remote is apply.
There are two tl494 chips on the driver board. Is it possible that both tl494 are bad?
Both chips are reading the same voltages
Before remote.------After romote
1) 0 v.---------------1) 0v
2)1.5v.---------------2) 5v
3) .2v.---------------3) .68v
4)1.5v---------------4) 5v
5) .18v---------------5) 1.5v
6) .2v----------------6) 3.5
7) 0v----------------7) 0v
8) 13v---------------8) 13v
9) 0v----------------9) 0v
10) 0v--------------10) 0v
11) .8v-------------11) .8v
12) 0v--------------12) 13v
13) 1.2v------------13) 5v
14) 1.5v------------14) 5v
15) 1.5v------------15) 5v
16) 0v--------------16) 0v
Before remote.------After romote
1) 0 v.---------------1) 0v
2)1.5v.---------------2) 5v
3) .2v.---------------3) .68v
4)1.5v---------------4) 5v
5) .18v---------------5) 1.5v
6) .2v----------------6) 3.5
7) 0v----------------7) 0v
8) 13v---------------8) 13v
9) 0v----------------9) 0v
10) 0v--------------10) 0v
11) .8v-------------11) .8v
12) 0v--------------12) 13v
13) 1.2v------------13) 5v
14) 1.5v------------14) 5v
15) 1.5v------------15) 5v
16) 0v--------------16) 0v
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Pin 4 is not shorted to pin 5, I grounded pin 4 and lost my 12 volts to pin 5.
( R3 burned.)
Replaced R3, and disconnected pin 4 from the driver board, now I have signal, but the relay circuit does not activate, unless I disconnect one leg of D8.
I'm trying to find out where this 12 volts on pin 4 are coming from, but its
very hard to fallow this trace.
Amp is playing audio when test it with the condition mentioned above.
( R3 burned.)
Replaced R3, and disconnected pin 4 from the driver board, now I have signal, but the relay circuit does not activate, unless I disconnect one leg of D8.
I'm trying to find out where this 12 volts on pin 4 are coming from, but its
very hard to fallow this trace.
Amp is playing audio when test it with the condition mentioned above.
Last edited:
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