Tektronics 2430 Ch2 input dead

[Nick Alexander]

I have a 2430 with channel 1 working fine, but channel 2 just shows a
flat line. Someone suggested to me that it is the input attenuator
or whatever the shielded box about the size of a match box that the
input plug connects to. He said there is a board in there that gets
a hairline crack. Does this sound likely? Has anyone repaired this
component? Any other ideas?

 

[mike]

Nick Alexander wrote:

I have a 2430 with channel 1 working fine, but channel 2 just shows a
flat line. Someone suggested to me that it is the input attenuator
or whatever the shielded box about the size of a match box that the
input plug connects to. He said there is a board in there that gets
a hairline crack. Does this sound likely? Has anyone repaired this
component? Any other ideas?

I like to start with rule number one:"If it ain't broke, don't fix it".
Which can be restated, "figger out what's busted before you go fixing
stuff at random".

Stick the calibrator into channel 2 and use channel 1 to trace where the
signal stops.
mike

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[Jim Yanik]

nic.alexander@gmail.com (Nick Alexander) wrote in
news:4ba6d6f1.0411130208.7c7a3d31@posting.google.com:

I have a 2430 with channel 1 working fine, but channel 2 just shows a
flat line. Someone suggested to me that it is the input attenuator
or whatever the shielded box about the size of a match box that the
input plug connects to. He said there is a board in there that gets
a hairline crack. Does this sound likely? Has anyone repaired this
component? Any other ideas?

It could be as simple as a broken connection from BNC to substrate.
The attenuator can be removed,taken apart,and checked.The service manual
tells how to remove/replace the attenuator.

One other problem those attenuators had was outgassing of the plastic parts
that builds up a film on the substrate contact pads and causes
intermittents.You can carefully clean the pads but don't remove the gold
plating.
*Don't crack the substrate(ceramic)*!!

--
Jim Yanik
jyanik-at-kua.net