Re: TDS744A input failure.
On Mon, 24 Apr 2017 19:21:38 +0000, you wrote:
Yes, so I think it is before the high impedance attenuators.The input resistance is constant - irrespective of the vert sens settings.There are high impedance attenuators (3?) between the coupling
The TDS520B service manual shows the 50 ohm termination before the
high impedance attenuators but I do not see how that could apply to
the 1 GHz versions.
Is there a significant DC offset that changes or does not change withI don't think I said that - not sure I understand.Didn't you say that the baseline trace is stuck at ground instead of
Interestingly, I came across this in my searching :-I am thinking that the relays are not switching and that the problem
is an open circuit between the relays and relay drivers so they are
stuck in an unusable state. At least that could be easy to fix; clean
the contacts between the module and printed circuit board.