Troubleshooting a Tek 2225 scope

[n1kt0]

I picked up a Tektronix 2225 the other day for really cheap, but with the caveat that the first channel does not work. Channel 2 appears to work beautifully; I get nice, clean traces of the probe adjust output on the scope, so I know the horizontal sweep and triggering circuits work ok.

When I have a probe attached to Channel 1, I get nothing. If I set the coupling switch to GND, I get the flatline trace, but it will not move when I adjust the vertical position potentiometer.

Really, I only need one channel for the occasional hobbyist work I do, but it would be nice to be able to repair it and get both channels working.

Does anyone have any suggestions as to where the problem is in this scope? A bad vertical preamp or final vertical amplification stage?

[djsb]

Start by reading this

http://www.sphere.bc.ca/test/tek-parts/troubleshooting-scopes.pdf

and try to narrow down the fault to a specific sub section using the front panel controls without taking the cover off first (as sugested in the manual above).

HTH

David.

[hysteric]

Hi,

I know it is not the same issue, but I just got my 2225 and "repaired" it over the weekend. I bought it off ebay, with the trigger on channel 2 described as not working. The issue was that channel 2 was so far out of cal that it prevented the trigger from working on that channel. You may want to start with the calibration adjustments to see if it helps.

[slateraptor]

A good start is download the schematic.. 

Then its to check volatges, and trace the signal until it ends.

http://www.eserviceinfo.com/index.php?what=search2&searchstring=tektronix+2225

Why do I keep seeing people point to this link for the 2225 service manual...that website doesn't have it.