The cal on the time base was full counter clockwise for previous test.
where should it be for a test like that?
I set it about half way when checking PS FETs.
where should it be for a test like that?
I set it about half way when checking PS FETs.
I get no signal on pin 1 of U2 when there is no input signal, would that indicate
the IC is no functioning properly?
the IC is no functioning properly?
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Tried a 072 no luck. It even cause U1 to heat up.
Any mod I can do to prevent the transformer from playing audio?
Any mod I can do to prevent the transformer from playing audio?
U1 may be defective. Remove R9 and see if that makes a difference.
This may be the problem with the noise issue. The amp may be losing the oscillator. If that's true and the oscillator drops in frequency as it drops out, it could be causing the noise.
This may be the problem with the noise issue. The amp may be losing the oscillator. If that's true and the oscillator drops in frequency as it drops out, it could be causing the noise.
When you installed the TL072, did it act the same as the 6172 or did it fail to oscillate?
Removing the resistor disconnected U1 from U2.
No change? Do you mean that U1 still heats up?
Removing the resistor disconnected U1 from U2.
No change? Do you mean that U1 still heats up?
when i installed the TL072 the triangle wave form was not so perfect but it was oscillating only with a signal in the input.
U1 only heat up when the Tl072 is in the circuit.
when i remove R9 i had the 6172 in circuit.Should i try it again with the TL072 in circuit?
U1 only heat up when the Tl072 is in the circuit.
when i remove R9 i had the 6172 in circuit.Should i try it again with the TL072 in circuit?
With R9 remove and Tl072 in circuit U1 does not heat up but other results are the same. maybe the transformer itself is bad.
Unless the power supply is shutting down or the IC is losing supply voltage, this oscillator should remain oscillating. You need to resolve this before you do anything else.
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