According to what you mean, I tried to mark the signal points in the figure below. Is this a connection?[Linked Image]

About J2，GPIB signal interface I found GND and RX/TX signals,is connected to U9,but this signal definition looks like the definition of RS232 signal,Other signals, such as 8000, A000, B000, 6000 I am still looking for
About J1，Under normal conditions，Short circuit socket,i check 3 wires,but GND was not found,Because based on experience,if it is RS232 signal，at least one wire is directly connected to GND.I do not know why it has to be like this.J2 I'm still looking for a signal,may take time

I cleaned the dust inside the host yesterday,Check various functions after booting,basically normal.
In the next few days,I will try to recalibrate it,Including voltage calibration, pressure calibration, flow calibration...
I will follow the progress steps,update content,take a good note,Share with friends who are still using it
If you have experience in maintenance and use, welcome to share

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