Infiinium 54810

[rtekal]

Hi,

I have a Infiinium 54810 A oscilloscope. The peculiar problem I am facing is that on Channel 2 the input resistance selection is inverted. The 1Mohm setting is giving a 50 Ohm impedance and vice versa. This prevents me from doing a Calibration. The self test shows no errors.

 I have tried swapping / replacing the Channel 2 input attenuator and the Acquisition board also. But the issue remains the same. Is it due to the expiry of the life of the attenuator or is there a software code that kills after a predetermined usage . Messages are displayed after self test that the switches are beyond their life expectancy and have to be replaced.

Regards

[Wallace Gasiewicz]

Are you referring to the "Attenuator Contact Warning" This only means that the attenuator contact has exceeded 2 million click,. It does not mean it has failed. There does not appear that the unit takes any action on this message, since recommendation for bench use after warning is just to watch the unit.
This is from the Infiniium 54810 Service Guide. It is a warning to folks who use this unit in production monitoring to warn them about possible future failure. It is kind of a "mileage counter".

Are you noticing the 50 Ohm / 1 Meg switch while using a probe or just connecting to BNC to AUX OUT???

Wally

[rtekal]

It was the same when connecting the probe also.

Well it resolved after I removed and reconnected the board and the attenuators. It passed calibration. But still wonder why that behaviour.

Thanks for the response

[Wallace Gasiewicz]

I had a similar problem using old Tek probes. The probes had broken wires in the 10X sensor pin. Made the 54810 go nuts. It didn't know what the input was. Kept switching at apparently random times to 50 ohm  I suppose the broken wire was contacting intermittently and confusing the input sensor.
Probably you had a similar problem but with an intermittent connection in the 10 X sensor path and fixed it by fixing/cleaning the bad connection in the 10X sensor pin path.
I took apart the old Tek probes and fixed the broken wire problem and they now work, but I do not think I will use them much.

By the way, you can upgrade the 54810 to 2Gs from 1Gs. There is a thread on this somewhere here. Very easy to do.
Also there is a way to change the hard drive to solid state drive.
The 54810 is my first modern digital scope. I really like it, I had older digital scopes that I did not care for at all.

Wally