Am I losing my Z-axis card?

[MBX5]

4020HT, CNC88HS 1995 vintage...

For some time now, z has been dropping a bit when approaching a part - maybe 1/16" or so, but obviously causes problems... I can remedy it by moving home, and power cycling, new CS, and good to go for a while..

Today - I got an E-stop on Z, and "AXIS CONTROLLER DOES NOT RESPOND TO NC"...Had to power cycle, re CS, and good to go for now...

Sound like I am losing my Z-axis drive card, or the amp itself??

(FYI for anyone that read my broaching post - I have not tried that yet...so this is definitely not related to that post LOL)

Thanks!

[denmar]

Sounds like Resolver problem inside servo motor.