Replaced the fuses on the RAMBO recently, and now when I turn my machine on I get an E1 MINTEMP error. I measured the resistance in the thermistors and got ~110kΩ at room temperature for both. I plugged constant resistors (3kΩ) into the thermistor pins of the TAZ, and got stable readings of 125 degrees and no error. Puzzled as to where else the error could be coming from. Could something be disconnected on the RAMBO? Do I need to replace the tool head? Lulzbot support won’t answer my calls or emails.
I’m not familiar with the Taz but I’m wondering if you possibly dislodged something whilst replacing the fuses. It sounds like from your testing the circuit board is responding properly in terms of temperature measurement.
One time I replaced those tiny fuses and accidentally unconnected a cable on the board, got some weird error, I think it disabled my media drive. Double check your connections on the inside and the printhead connections.
Update: it stopped working again. I think I may need to replace the whole motherboard - seems like there are some broken connections that I can’t easily fix.
It’s far, far more likely that it’s a cable than the motherboard. Before you replace the board, try the cables. I’d start with the ones that move a lot – the external box-to-print-head cables. Connectors are also suspect.
You can try routing an external wire from the board all the way to the print head, bypassing all the cabling and connectors - that’s what I’d try before sinking a lot of money into a new board or even a new set of cables.