Yes, It's possible repair the A5 card.

Remove metal cover and in upper right side you'll see 4 mosfet transistors and a voltage regulator.

These transistors supply voltage for the steering motor, check these mosfet surely you have one shorted. Also check transistor drivers.

Regards

I had checked the steering motor after switching into other Reach truck of same spec.. there is no problem with steering motor,, then i changed the A5 electronic card.

The problem is in A5 Card only, is it possible to check/ repair A5card..

Please suggest.. also need the details of Repair engineer for these Cards & Transistor controller 180728-001 AC Drive..Please help me out.. i need to repair 5 Controllers..

It's probably your problem is in A5 electronic card. Power transistors inside the card are shorted.

Regards

Take the carbon brushes out, unplug the steer motor, undo the 2 x long bolts & lift the motor housing of the rest of the steer motor, blow out all the black carbon dust from the housing & also the motor armature with an airline.

Check the steer motor hasnt shorted out internally.

Why was the tacho changed?

Did the steer motor fault started immediately after the tacho was replaced?

Has the wiring to the tacho been checked in case its been trapped / shorted?

You havent untwisted the tacho wires?