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I can’t meter a resistant on the gold wires it looks like an open circuit.
This says the thermocouple in the A1 bulkhead is open. This is the #1 failure mode for these sensors and is caused by too much input power. The A1 assembly is unfortunately not repairable.
The A1 assembly 08481-60042 and alternate 08481-60009 are both obsolete. I don't think I've ever seen them on ebay or elsewhere. And even if you could find one and replace it, the sensor would require recalibration which would be additional cost.
At this point, I would start looking for a replacement sensor. If you're looking on ebay, make sure you get one that is "Used" since according to ebay's definition of that category it's supposed to be working. That will give you a chance to receive it, test it, and return it if it's not working. You can sometimes find a bargain from someone selling one that is "Used" but untested.
I don't know what power levels you're looking to measure, but if you can find a good deal on a diode based sensor such as an 8481D, you could buy that instead along with some quality attenuators.
And one other note when shopping for sensors: Make sure it has the calibration chart on the sensor. If you don't see it in a photo, ask. For some reason, many sensors I've seen have the chart ripped off or defaced and this will require you to get the sensor calibrated to regenerate the chart.
You could try shorting U1 between pins 1 and 9 and try zeroing the meter. Or you could also apply a short at the location where the "gold wires" were connected. Both of these short the input. Use your judgment on mechanically what's possible
If you can get a short in place, the meter should be successful in zeroing. If it still won't zero, we need to keep digging.
I have short at the location where the "gold wires" were connected and started zero A but it didn’t zero error 01.
I would expect the meter to still be able to zero. So either there is still a problem, or it may be the long leads you are using are either introducing too much noise, or too much offset from thermal effects.
The range for zeroing at the input is extremely small. With the thermocouple intact, +/-15mV from the meter through A2R1 404k, and then through the thermocouple 200R + U1R1 15R results in +/-8uV. With a test short the range is even smaller.
At this point you've already determined the sensor is unquestionably dead. I would find a replacement sensor before concluding anything about the meter.
If you still want to see the meter zero, you could try holding a 200R SMD resistor across the input pads with a toothpick. There's not much you can do to make the sensor any worse at this point.