Pump Issues, turbo kicking in on power up

[LCbob]

Hi
Hopefully someone can help with this issue.

The 6890/5973A was working fine, vented to clean source and then pumped back down. Problem being the foreline pump does not pump down and the turbo pump immediately kicks in.

There is also no power to any fans and mainboard. I have checked the foreline pump and it works fine. All cables are correctly connected.

My hazy memory seems to remember seeing this problem before, but a long time ago. So before I go to technical support, anyone else seen this problem?

regs

[Ron]

Blown fuse? There are several internal fuses. I am surprised that the high vacuum pump is turning on, but that may be a function of the main board not controlling things.