Baytekk wrote:
I've seen a this type of problem in the circuit boards of other
Tektronix equipment, this time it's afflicting two of my DM44s.


...snippety for bandwidth..

My question is:
Has anyone had the same experience with the DM44 and found all the
defective areas on the board and/or is this problem related to age
and will it become wide spread? Please advise.
Thanks in advance, Mike at Baytekk Designs


Hi Mike,

well this problem I have seen with instruments used in industrial
areas. As far as I can say about it is a problem of the dirt covering
the boards. And, very interesting, it is most times NO VISIBLE dirt. I
asked chemist from the local university, and he just nooded : He said
that's often hapend due to certain sulfur and chloride chemicals that
contaminate these boards in electronic devices (sorry I forgot about
the full names of the chemicals).

In my situation this helped: thorough cleaning, comparable to the
dishwasher method Jim Yanik descreibes in the newsgroup (use a little
google time to find his articles).


Don't simply scrap the boards, some of the components (mostly
LD110/111 chips) are real hard to get nowadays (at least here in
europe)

hth,
Andreas