modified A50 cable to bring ground to
Testpoint
Click here for A50 testpoint solutions
A55 and A52 Cut New and Old phones Testpoint
New
Old

You need to remove resister




For Older SL55 <= V15

For newer SL55 V16 + models just short the resister to ground
Click here enlarge Sl55 V16 + second method

You need to remove resister to unlock

Click Here for CF62 Testpoint Cutting Method