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Maho MH800W won't reference, no fault codes.


Nov 21, 2008

I recently bought a Maho MH800W with Heidenhain CNC 234. Indramat, Year 1991, serial 082678.
When I went to see the machine it referenced, I jogged it into the transport position & did a deal.

After re connecting the machine it gave an error message "X-MEASURING SYSTERM DEFECTIVE A" as soon as the CNC is enabled. The drives remained off.
I have since fitted the repaired scale. The CNC will now enable, you can hear the drives come on & the cnc offers to pass over the reference marks but it just doesn't do anything next.
From memory it should highlight the axis being referenced & do all 3 automatically in sequence after the cycle start button is pressed or it can do them individually if the appropriate axis jog button is held in. There is no highlighting & no action at all regardless of which key is pressed.
I can set a new datum at this point & I get "key non functional" with other keys so the DC voltage is present & I think the keyboard is working.

When I took off the old scale I had to hand wind the X ballscrew to gain access to the fixing screws. Maybe it got "lost" in the process. No fault codes on the screen or on the code reader on the panel door, all LEDs on the drives are green, the only thing I can find which is wrong are the 2 drive heatsink axial cooling fans don't come on. Maybe they are thermostatic. Also the guards are all off at the moment & the vertical head pushed right back. I have defeated the door switches with cable ties, can't find any other sensors which might tell it where the head is. Any ideas & help will be much appreciated.