Hi guys! Been a little while, but it is busy here. The Title supposed to be Nortel, not Norstar... but I can't change it?
I have a actually two Nortel NT5B01 616 phone systems. 6 lines 16 phones. Number one quit on me like 3 months ago. So we put a spare one in and that quit yesterday too in the exact same way. Now we don't have any phones. What happens with both of the phones systems that they act like there is no power. I verified fuses o.k. diodes and mosfet O.k., all electrolytic caps are good, but zero power out. There is 169V on the filter cap. I can see pulsating voltage, on the 2 optos and the driver IC, but the damn thing doesn't start. The white opto SCR is a 4N39 and that checks out. I see a diode on one side and an SCR on the other. Than there is this UC2844 PWM and another opto. There are no schematics available to my knowledge. If someone has one, I'd be interested! That is as far as I got.
I have a actually two Nortel NT5B01 616 phone systems. 6 lines 16 phones. Number one quit on me like 3 months ago. So we put a spare one in and that quit yesterday too in the exact same way. Now we don't have any phones. What happens with both of the phones systems that they act like there is no power. I verified fuses o.k. diodes and mosfet O.k., all electrolytic caps are good, but zero power out. There is 169V on the filter cap. I can see pulsating voltage, on the 2 optos and the driver IC, but the damn thing doesn't start. The white opto SCR is a 4N39 and that checks out. I see a diode on one side and an SCR on the other. Than there is this UC2844 PWM and another opto. There are no schematics available to my knowledge. If someone has one, I'd be interested! That is as far as I got.
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