atcomsystems.ca/forum Forums Other TDM Phone Systems Sprint - Tadiran Telephones & Systems Tadiran APS-SL Power supply

Thank you Avidcomm. It looks like you nailed it. The local vendor has informed me that they had the issue diagnosed by a local agency and it seems that some of the electrolythics are drying out and preventing the PSU from restarting. I'm now upto 8 failures this year. Two came back after about an hour when removed them from their system. I've asked for more specific information (ie which ones) If they tell me I'll mail you directly. Tadiran have nothing to say on the issue. Thank you all for your input.

Regards, 63.

I have had such problem with two six-years old APSsl. I received informal help from Tadiran tech support - they suggested to change capacitor 211 on APSsl board. It is originally 25V 100mF, and have to be replaced with high ripple current, low E.S.R and long life capacitor, which value should be 150°C, 100mF, 35V, 20% (Nippon Chemi-Con - capacitor LXJ-35VB120MH12, Jamicon - capacitor WGR101M1VF, Nichikon - capacitor PL-1V101MPH).
By the way, Tadiran have good specialists - tech support gave me fast, clear and correct answer - I have changed those capacitors and now everything is good

Hello Muter. I'll source some caps and give it a go next time. I agree by the way that Tadiran have some fantastic engineers. Technically excellent and rightly proud of their product. Those that I've worked with were certainly top drawer in their field. However my vendor insists there is no problem with APSL's that Tadiran is aware of. I hope this may save you some cash too Avidcomm if you are reading. Thank you again everybody for your time and help on this issue. Regards 63.

The problem with the Tadiran APSL is the Capacitor C211 (100 micro farad). It fails because it is under rated at 25 volts. The capacitor needs to be replaced with a 50 volt capacitor. Observe polarity - the minus side of the CAP goes toward the card connector. Make sure you flow a little solder onto the connections as you heat them. There is a lot of copper to heat up before the jounts are evacuated. Heat the joints sufficiently as you resolder the cap.