I originally posted this in the data system section but thought it might be more appropriate in the LC-MS etc section...

It's a bit of a long shot, but quite some time ago a Waters Micromass ZMD electrospray single quad instrument I was maintaining had to be powered down for a few weeks. Trying to get the thing to come back up, the fans spun up when powering on the unit and the front status LEDs lit briefly, then switched off. Masslynx does not communicate with the instrument, indicating that it can't establish communication with the transputer. It's an instrument with a proprietary interface (ISA card installed in the PC).

I took the cover off and reseated all the cards, which worked when we last had a similar issue, but this didn't improve things. There's a diagnostic LED display on on the main board that flashed (the number '8') as the unit was powered on, but then remained dark.

Reseating the ISA card in the PC didn't do anything either, nor did unplugging and replugging the cables.

I began to suspect the capacitors on the main board may have become leaky due to the age of the instrument, so I took the main board home and left it on the workbench, where it has sat ever since...

Unfortunately I can't borrow another main board to test whether the installed one has failed, as these instruments are quite scarce nowadays, especially in this part of the world.

I was wondering if anyone's encountered a similar issue with these old Waters Micromass mass specs? When they work, they're super rugged and keep going and going... until they stop, then it's a pain to get them going again. They hate being powered down.

I've replaced gauges and turbopumps internally to keep the thing going, I'd hate for it to be consigned to spare parts.