[Xavior]

Hi there,

Error Definitions:

123 SPINDLE DRIVE FAULT - Failure of spindle drive, motor or regen load. This can be caused by a shorted
motor, overvoltage, overcurrent, undervoltage, failure of drive or shorted or open regen load. Undervoltage
and overvoltage of DC bus are also reported as alarms 160 and 119, respectively.

993 AMPLIFIER SHORT CIRCUIT - This can be caused by any of the motor leads shorted to each other or
shorted to the 320V return. This can also be caused by a faulty amplifier. Check all of the motor leads and
make sure they are properly connected. This can also be caused by a faulty amplifier

Looks like another vector drive thread and problem here that plagues the haas mills + lathes that often results in needing another drive, but i am hopeful. All week we have been having issues with the vf5 not allowing us start the machine as the DC Bus was not getting up to the right number and often needed to be on for about 1 hour before working.

We have been doing a lot reading and found that this dreaded A 7800A chip (white 8 pin) can fix the problem due to bad design of the board and its location next to a hot resistor. We picked up one of those chips and proceeding to open up the vector drive today to replace it along with soldering a hot swap IC seat so we can easily throw new chips in if it happens again.

Upon reassembling the machine and vector drive and starting it up again, now we are getting the proper DCBus of 355 and we confirmed it by checking the posts on the 35 amplifier with an voltmeter set to DC. We also took the thumb screws off and checked the P17 plug to find that we were getting "-3.58" as a result. I am not quite sure why it is a negative number? Is this a problem?

Either way, now we have made things worse by changing this chip with two new alarms, 123 and 993. We cannot for the life of us clear these alarms and it appears we have made a mistake tackling this ourselves. Does anyone know if the resulting "-3.58" is correct or if there is something else we should be checking to confirm the drive is dead or if we can fix it ourselves without replacement or rebuild?

Gah! This is stressful.

Here is the picture of our work with the A 7800 A chip, sitting on the swap-able seat -> https://app.box.com/s/6gs8rwc3u6gzt1716av31r4v9h0zrvj2

[dcis77]

I have the same problem on my VF-2!

Amplifier Short Circuit...

I can not fix it...

[erikfriesen]

There is another op amp that needs to be replaced besides the 7800 chip. If it is damaged you'll get a negative voltage like that. See the schematic on the web the guy posted . LF411CD I think. At least it fixed my 15hp drive.