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Old 17th May 2020, 6:17 pm   #30
TonyDuell
Dekatron
 
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
Default Re: Quiet or no dial tone in a GPO 706

OK, you do have the regulator PCB fitted in its socket 'upside down'. That is with the end that connects the 3 middle contacts on the socket with a simple PCB trace in the socket.

Connect one multimeter probe to T19 and leave it there.

Put the other probe on terminal 4 of the ASTIC. Should be 0 ohms or close to it (this checks the gravity switch contact and associated wiring).

Move the probe to terminal 5 of the ASTIC. Should be 22 ohms (this checks the ASTIC winding, even though you've already done so)

Move the probe to that PCB trace on the regulator that I mentioned. Should still be 22 ohms (this checks the wiring from ASTIC pin 5 to the regualtor terminal C).

Move the probe to T3. Should stll be 22 ohms (this checks the wiring from regulator termnal B to T3).
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