Could you make it simple and post the output voltages from the power supply (pins 15/16/17/18)?
Does not make sense - against what point you are measuring - pin 22 or somewhere else?
And what are the voltages on C601/602?
Hi Raccoon1400,
I just serviced one of those. DO NOT disconnect the tone controls, these receivers work fine and are reliable.
The two offset controls are not connected together, there should be zero interaction as the supply isolates them. Since you are repairing this as a business you should understand how these things work.
I just serviced one of those. DO NOT disconnect the tone controls, these receivers work fine and are reliable.
The two offset controls are not connected together, there should be zero interaction as the supply isolates them. Since you are repairing this as a business you should understand how these things work.
Sounds a bit strange. Are you measuring to the Zener's from ground or actually across the Zener? Wondering about cracked/open print. Lots of AC could give a confusing reading but these are off the main 8000uF reservoir caps so I would expect lots of other issues if there was a problem there.
Thought I'd checked the voltages from both the circuit ground and chassis ground. But it appears I did not do this accurately. I remember measuring board ground to chassis ground but seems I must not have measured from a clean enough pad because I didn't detect the problem, which is that I do have a bad ground connection. Now to fix it...
Or maybe every time I tried to measure chassis to board ground the pressure made the connection again.
Obviously I should have caught this sooner, but it is easy to get turned around working on these things. Tempting to see really weird readings and think really weird problem... But it is always simple in the end.
But next time I will catch this right away.
Thanks everyone for the help.
I will not be disconnecting the tone controls.
Or maybe every time I tried to measure chassis to board ground the pressure made the connection again.
Obviously I should have caught this sooner, but it is easy to get turned around working on these things. Tempting to see really weird readings and think really weird problem... But it is always simple in the end.
But next time I will catch this right away.
Thanks everyone for the help.
I will not be disconnecting the tone controls.
