Oscilloscope Vertical Deflection Problem (?) - Tektronix 2336

Discussion in 'General Electronics Chat' started by royalt213, Aug 29, 2011.

  1. royalt213

    Thread Starter New Member

    Feb 27, 2009
    Hello all,

    So, I bought an analog Tektronix 2336 (2336 YA, actually) scope off of eBay a few months back. Almost everything appears to be fine with it (i.e. horizontal beam, visible CAL square wave, etc.) as far as I can tell, as this is my first scope. However, when I try adjust the beam vertically on the screen, I can only get it to go about halfway up the screen. Similarly, when I adjust it down past the bottom of the screen, the beam becomes scrambled near the top of the screen.

    I figured this probably had something to do with the vertical deflection being misaligned. I've looked through the service manual a number of times, but I can't seem to find anything about this specific problem. I don't want to butcher this thing, but I am confident that I can fix it on my own.

    Has anyone ever done a fix like this on a similar model? Does anyone have any suggestions? Any help would be great. I can provide more details, if needed.

    ALSO, I noticed that it's EXTREMELY difficult to find copies of the operator's and service manuals for this unit. I have PDF copies of them now, after paying a small fee for them :)mad:). If anyone shows interest, I would be glad to post them online for free download as gratitude for any potential help.

    Thanks in advance.
  2. SgtWookie


    Jul 17, 2007
    Well, without having access to the service manual ourselves, it'll be rather difficult to offer more than general suggestions.

    You might see if the output range from the vertical position pot looks to be normal.
    Bad caps are normally the most likely possibility. When caps go bad, they can also ruin parts in their general vicinity.
  3. Rob36

    New Member

    Sep 30, 2011
    Hello, just found this Forum doing a Google search, and saw that you mentioned that you had a PDF of the 2336 service man.
    I see that you posted in Aug, so I am not sure that you have fixed your scope?
    I am a retired Technician, and may able to help!

    Further I have a Tek 2335 same family as your 2336 scope.
    Last night while troubleshooting an item, I smelled the dreaded odor of a resistor burning, eminating from the 2335 scope.
    I did a Google search and found that on the A15 PC board, that it is very common for C108 (.005 200v 1%) to short taking out a 1/4 watt resistor.
    Bingo that is what happend to my scope the C108 was shorted and the a 1/4 watt resistor was just a Black charred body with leads attached to the PC board.
    I do not have a Service manual as of yet, and I cannot determine the value of the Charred resistor?
    I was wondering if you would be able to just send me a pdf of the the A15 board also marked" Vert Out/HV Power". That would allow me to make sure that I am replacing the correct value back into the scope.
    ( Other searches mentioned the value of a 1/4 watt resistor that smokes is a 1.6K 1/4 watt not sure of the tolerance or if that is the same one that is charred in my unit).

    Also I would highly recommend that you change the C108 , as it will probably fail , like mine and many others.

    Thanks rob
  4. Fraser g Shim

    New Member

    Mar 12, 2012
    With ref. to Tektronix 2336 Scope, i have just bought a used one on Ebay, and i'am almost sure it's not working, i would be interested in a repair manual on a pdf file if one would be so kind