Fuel XIO 12V Bias low; XIO 5V high - where to measure?


New member
Oct 9, 2021
I'd like to verify if I have to replace the env monitoring chips in my Fuel. Where can I measure XIO 12V Bias and XIO 5V?

If I have to replace the DS1780, does anyone here know which one is responsible for the two voltages above?


Feb 4, 2019
I have not seen this information anywhere unfortunately, possibly someone else has? Only a mapping of the DS1780 to NODE temperature sensors: https://cz7asm.blogspot.com/2021/03/replacing-monitoring-chips-on-sgi-fuel.html

From the site above:

Note on the Vin pins 14-18, at least you could narrow down the voltage input to the chip, and one of the chips could be monitoring XIO 5V and 12V Bias? Maybe the 0 or 1 chip (in the image of the linked site above), given it being XIO?
Screen Shot 2021-10-09 at 10.26.48 PM.png

If you're suspicious about specific inputs to one of the chips I could try to measure what they are from a working Fuel for comparison purposes. Although some of them are packed in pretty tight, so it might be difficult.

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