Mits dwc90G wire grounding out

[dleonard]

We have a mitsubishi dwc90G wedm machine and are having problems with the wire grounding against the work piece and the machine doesnt detect a ground condition so the table just sits there instead of backing up to get the arc going again. The machine continues to feed wire while grounded and wont stop on its own. can anyone help? Normally the machine will move the table back and forth to get the arc going again and if too much time goes by while its grounded, it will set an alarm (short time too long)and stop on its own. Service thru mits is not an option right now because of a hefty registration fee of $5000 before they will do anything.

[BACKFIRE]

try putting a new ring terminal on the small wire connected to the upper head.
if that doesn't work, check the avr for a blown fuse.

[dleonard]

Thank you for your reply! I checked the ring terminal and found the ring is soldered to the wire so I dont suspect a bad connection, and I cleaned the terminal. I dont know where the fuse is for the AVR(automatic voltage regulator???). This problem is also intermitant, sometimes works sometimes it dosent. it seems to come and go with no reason for correcting itself. We are presently reloading the system software. when the problem shows up, the volt meter on the front panel reads 0, but the contact light on the hand control and crt screen is not lit while the wire is grounded(in contact with the work piece).

[Othatvideo]

We had a Mits90H. Similar but not exact same problem. The offending unit was the oscillator board.

Brent
-Mine is not to question why. Mine is but to Tool, or Die. (Charles M. Smith)