The DSO1152s oscilloscope came with a non-working channel CH1. CH2 is working correctly. Self calibration test aborts at step 23/34 with error 0x502. It is possible that an overvoltage was applied to the input. Faulty elements were replaced: R133, R201, R487 in the input circuit, then without the necessary information I have difficulty.
I look forward to your help with the next steps.