Hello Victor,... I strongly recommend to ship the mic to its birthplace and have MG replace the broken module.
The backplane of the capsule is connected to ground through a 200MOhm resistor and the front membrane getsabout + 40 Volt and the back membrane gets - 40 Volt.
If I remember right, the "S" was indicating the higher 80V in UM70S, but plain UM70 mic was MV692+UM70(capsule) with 60V polarisation. The confusion about the 40V may be due to the use of SMS-series capsules with MV692. M94(M62, older version)needs 40V but cannot take 60V, so a 10M resistor is integrated in the capsule-head to adjust the voltage.Regards, Esa