On Sun, 27 Jul 2014, dave wrote:

On 07/24/2014 08:14 PM, Chris B. wrote:

about 100 ohms.

I'd just like to have an idea of what the problem might be before I
change any more components. Now I'm half wondering if it's the IC and
the fact that it's facing up and has a fan on it is allowing it to
work properly. Anyway, thanks for reading my long story and I'd
appreciate any suggestions you have.

This is where I downloaded the service manual:

http://elektrotanya.com/tektronix_22.../download.html

The problem is you bought the scope without the manual that should accompany
it as it travels through life. I lucked out and got my $225 465 from a Tek
sales rep/ham. The 2" thick manual includes all repairs, upgrades, part
substitutions, liner notes, etc. In a perfect world the manual travels with
the device.

Wasn't there a place to hold the manual in many of the scopes? I can't
remember, but when I got my 545 (with some plug-ins) I seem to recall the
manual was in some slot or place in the case. Certainly the hospital
discards came with manuals. I was lucky, someone I knew grabbed it
all before it was tossed out

Michael