7601 appears due to DAC value drift,
It has many causes.
1-BSC Clock problem.
Kindly check BSC clock oscillator value,if Clock,Transmision and BOIA are OK,
then Adjust DAC value on BTS site 2048 and send it to BTS through BTS manager.
after this refresh OMU by MML.
It should be clear.
Some time this problem appears on many sites connected one HUB.