Schematics for the analog board of the 2306/2302

Hello,

Would it be possible to obtain schematics for the analog board of the 2306/2302
Battery Simulator?
I'm trying to fix my 2306  and having the schematics would be a great help.

Hello, sorry but we won't share schematics for those products. If you are able to localize the problem and share specific info on what's wrong we might be able to provide guidance, but perhaps not.

The 2306 is able to be repaired by us should you want it done professionally: https://www.tek.com/en/services/select-factory-service-request

Hello,

Thank you for your response. I sometimes buy broken test equipment and then fixt it as a hobby.
I will appreciate any help on fixing my 2306.

Both channels on my 2306 aren't working. I only tried to diagnose channel 1 so far.

The symptoms are:
- when the output is off an no load applied to the output, the output voltage is +17mV, 
  2306 reads -28mV at that output, current is read as 0.0000A
- when the output voltage is set at 15V (voltage protect sat at 8V), 0.25A current limit
  and the output is turned on, the output voltage is +19.8V, while the instruments reads -30V.
- when a load is applied to the output, the out put voltage stays near 19.8V, voltage reading
  is about -30V, the current measurement is close to the load current.
- when the load current is more than the current limit, the output stays on, the display
  starts displaying 'LIM' after the measured current.

None of the DACs are written to when cycling the output between on and off state.
Is this because some of the measured signals are out of range?

- external DVM input reads random numbers when the input is floating,
  when the input is biased with small positive voltage (>+0.1V), the dvm reading is 'overflow',
  when the input is shorted, the readings are in -140 .. -130V range and when the input is biased
  with -0.1V, the reading is -1790V, at -1V, the reading is -19200V and at -5V it's -102100V.

Is it possible to disable the Voltage Protection Circuitry by modifying the circuitry?

That would be very helpful in troubleshooting.

I removed Q421 (current regulator) and some features of channel 1 started to work.
I can control the output voltage but offset and scaling are wrong. At 0V set, the output voltage is 3.7V
and at 15V set, the output is 13.6V. Output voltage measurement are incorrect. At +3.7V, the measured
voltage is -6.3V, at 13.6V it's -22.7V.

Current limit, current measurement  and output impedance control work well.

I'm guessing the calibration coefficients are wrong.
I tried to calibrate channel 1 and the calibration procedure seems to be passing
but I can't complete the calibration since channel 2 isn't working.

Could you let me know the part number of Q421 please? Is it the 1N5297UR?