Source Heater Error: Timeout

The source and analyzer heaters, the wires with the beads on them, disconnected from the white ceramic source connector board should Ohm out at 14 or 15 Ohms.  They must be open to ground.

The source and analyzer PRT (Platinum Resistance Thermometers), disconnected from the white ceramic source connector board, should Ohm out at ~109 Ohms at room temperature.  The resistance goes up with heat, so if it is already warm the resistance will be higher. 

Also check the cable connections to the analyzer side board -- DO NOT unplug or plug them in to the board with the power on!!!  That will damage the instrument.

Thanks paulsalverda I'd say my thermocouple resistance for the source was definitely too low - more like 14 Ohm for that. Would a fault there prevent both zones from heating though? That's the puzzle I'm stuck on tbh. 

Absolutely!  If the PRT is 14 Ω instead of ~109 Ω, the system thinks the source is, oh, negative 340 degrees (joking guess), and when the heater turns on and the resistance does not change it thinks something is wrong and shuts off the heaters, both of them, for safety. If it did not, the heater could run away without control and then things get melty.

Brilliant! This is super helpful paulsalverda. Thanks for this. I'll double check that thermocouple but that makes sense.

OK, so we managed to get a replacement 5977 Ext Heater Sensor Assy and I've replaced it but still not working. Vacuum comes down as normal but neither the source nor the quad temp ramp up at all. I remeasured the resistances of the heater and the sensor on the old assy and the new one. Old one reads 13.8Ohms for the heater, new one 13.1 Ohms. Sensor reads 108 Ohms and the new one reads 110 Ohms. So, similar. I'm not getting the error I was getting before but it's not ramping the temps. I checked the fuses again (both inside the left side and the rear 250V 12.5A ones) and they all seem intact.

Main board for the MSD then?

Hi NB,

There are so many test points on mother board.

Check test point TP600 and TP602 and tell what value is showing in multimeter.

Or you can contact to your local agilent support to diagnose it...

No errors now, just not heating at all?  After waiting for good vacuum, does everything else work? Filament turns on, PFTBA valve turns on/off, ions?  Don't do this for a long time with the source cold but it won't hurt it.   Is there any chance that the main board to side board cables were plugged in with the power turned on? 

No errors now, just not heating at all?  After waiting for good vacuum, does everything else work? Filament turns on, PFTBA valve turns on/off, ions?  Don't do this for a long time with the source cold but it won't hurt it.   Is there any chance that the main board to side board cables were plugged in with the power turned on? 

\So the main screen of the MSD is showing 'All faults cleared' then 'Not Ready' at the bottom, which then changes to 'All faults cleared' and 'Fault' at the bottom. This flips back and forth but no error on screen.

Vacuum comes good with no issues but the temperatures of the source and the quad basically aren't budging. After waiting a while the source is at about 41C which, feels about right to the touch. Quad was ready about 26 though, which seemed awful cool. Since I figured the quad should be warmer as it's closer to the transfer line, I swapped the quad heater sensor with one from a nearby 5973 but that made no difference either.

I actually didn't check filament / PFTBA valve as tbh I wasn't sure it would tell me anything but I guess that might help isolate which board was at fault?

Checked all the fuses again but all of them are solid.

As far as I'm aware no chance the cabling was wrong when the unit was power cycled. I was pretty careful with it as the voltages at play are higher than I'm comfortable. I switched the unit off and unplugged it each time before opening it up at all. Of course, maybe this was done before I arrived, maybe just damage from the power cut. 

Previous power out caused one of the left side fuses to blow so perhaps this subsequent power cut damaged something on the main board which was weakened by the first cut a while back.

Your power outages are a problem!  It's relatively rare for any power fail to cause damage, but if it happened once it has probably happened again and worse, sad to say.   Most electronic components are not "weakened", they work or don't work.  At this point the thing to do is to call Agilent (US is 800-227-9770) and set up a service call.