problem on STDM board when AC off

[bouciakt]

Dear all,

I have problem with BTS 3606AC (CDMA). when AC off, STDM suddenly became fault/inservice and alarm "power amplification closed" appears. I check power monitoring by LMT found voltage around 47 VDC. After Voltage 43 V, bts down.

Anyone know..why only STDM down but other module still normal?
Actualy at what voltage STDM fault/inservice. in my case config is 3 sector 2 carrier?

Any advise...

Thnks