MSD won't power up - blown fuse

[Roxanne42]

Agilent 5975 MSD, about 3 years old - had it properly shut down for the week-end. Installed a column this morning, powered stuff up, the MSD started up for about 2 seconds then stopped. One blown fuse was replaced, system restarted - same thing happened (fuse quite black, which would seem to indicate something big).

I'm having someone from the electronics shop come to look at the internal boards tomorrow, but if anyone has any clue of what we are looking for, any input would be appreciated.


Thanks,

Roxanne.

[Ron]

Did the fuse blow after the electronics were turned on, or when the pumps started up?

[Roxanne42]

It was hard to tell due to the very short time of it remaining on - but we found the problem; it was an issue related to the rough pump (which was better than the alternatives!)

Thanks.

[lovemymoe]

I know it's been a few years but I'm curious as to what it was about the pump that caused it? After a filament change, I noticed mine sounded just kind different about 6 weeks ago, nothing I could really pin point or felt highly alarmed over and other than a steady decrease in sensitivity that leveled off, it was fine. I came in today and it was off because one of the back fuses was blown and the holder is charred. After reading this post, I'm wondering if (suspecting) this is a larger problem than a fuse that grew tired of our occasional brownouts...

[James_Ball]

One thing you can do for a diagnosis of a rough pump, if they have the shrouded plugs that only fit into the back of the instrument, is to use a spare computer power cable to power it up. The computer cable where it connects to the power supply will fit into the shrouded end of the rough pump cable so you can then plug it into a wall outlet(assuming you are running the 110V pump on U.S. power service). I have done this to see if the rough pump is the problem or the MS is the problem.

Unless you have a heavy duty power cable from a laser printer or something, you don't want to keep it plugged in very long as the cable will over heat from the power draw. But it can help you diagnose a problem fairly quickly.