tetra mtp850 problem

[battabatta3]

After I read to my MTP850 in tetra cps plus my radio gone dead. it can not start. and near I put the computer to write the unknown device what should I do

[RA1AIE]

First, check cable and USB port. Maybe one of it is broken. Check on another PC.
Second, if cable and port are OK - try to use serial cable to read radio.