Some customers complain that their FF-980REV OTDR can not be turned on any more. The problem was often caused by not right operating on the OTDR when they test RJ45 cables. Please do not test RJ45 cables if signals exist in RJ45 cable. To proof, please do as following steps,
1) Disassemble the device.
2) Press and hold power on button, and meantime, checking the voltage of TP11 point. It should be around 5.2V. Watch the video.
3) Remove N10 and N15
Now, OTDR should be ok to turned on. But RJ45 sequence and RJ45 length functions do not work. Other functions works in right situation. Please contact us to have new N10 and N15.