DSO 5072P input stage problem

[YannickF]

Hello

I think I burnt the input stage on my oscilloscope this morning.
I was looking for the pulse output (in order to build a tachometer) on a motorcycle alternator, and maybe too high voltage was applied.

Actually, both CH1 and CH2 are OK (tested with 5V 1Khz output) but they don't work at all if I choose 5V/div sensitivity. (Signal stay on 0V)

Which component(s) may have been killed ?

Regards

[homeboy]

Directly go to this website: "www.eediscuss.com" to bring up your question. May be technical support can give you a hint.