Tektronix TDS3064B probe sensing terminals - scope reset

[adsos]

Hi All,

I recently bought a used Tektronix TDS3064B - seller mentioned that the control board (front panel board) got replaced. I was hooking it up to a signal generator to do some initial testing using ordinary BNC connector and noticed that when pushing it in, the scope would reset. The only explanation is that the BNC connector shorts the probe sensing pads on the scope. My question is - is it "normal" or should I be worried that the scope is faulty ?


Many thanks for all replies!

[picburner]

Hi,

the distance between the top of the female BNC and the sensing pad is about 11.30mm. I tried to insert a non-isolated male BNC and, even when pressing, it does not touch the sensing pad (even if it goes very close).
Check that the distance between the top of the bnc and the sensing pad is not less than the measurement I have provided.

[adsos]

Thanks a lot for the info - I will check the distance. Would you know if shorting the sensing pads would cause the scope to reset?

[picburner]

On the sensing pad there are the power supplies for the probes, + 5V/-5V, +12V/-12V.
These voltages should be protected by a PTC for each line but if the bnc touch in the bottom shorting everything together to ground it is understandable that the scope will reset.

[adsos]

Thanks again for explanation - I would have expected the scope to issue an error message instead of abruptly resetting but I guess it is what it is. Now I suspect that either I have some doggy BNC connector which is not of the standard size but more likely, after installing the control board, it was not seated properly and is moved a little bit inward - I will check it after I receive my USB floppy emulator as don't want to open up the scope twice....