Hartke LH1000 No Output

[misterc57]

I'm looking at a LH1000 with no output. Powers ON and I hear two relay clicks.

I found that the single 12AX7 tube is dead. Swapped that and still no output, and found that U2-A (NJM2068) has signal at pin 3 but no output at pin 1. I have +/- 14.9 VDC at pins 4 and 8.

So I figure that U2 is bad and needs replacement. Wondering if I need to check anything else before finding a replacement and if I can swap any dual op-amp in its place.

Schematic attached. Thank you

hartke-lh-1000-v3-8.pdf

[Jon Snell]

Check the DC voltage on pins 1, 2 & 3 they should all be sat around zero.
If the voltages are incorrect, supect the 3pin lead to the rear jack.
If that is OK, a TL072 or 4558 will work seamlesly.

[misterc57]

Check the DC voltage on pins 1, 2 & 3 they should all be sat around zero.
If the voltages are incorrect, supect the 3pin lead to the rear jack.
If that is OK, a TL072 or 4558 will work seamlesly.

Pins 1 and 2 are 150 mV, pin 3 is zero.

I think I have some TL072.

Thank you

[misterc57]

Great layout...The pre-amp board is impossible to remove.

[misterc57]

Finally got the board up, swapped in a TL072. All is well.

Thank you