Tektronix 4051 repair.

[Pete Lancashire]

They look pretty bright to me for a DVST screen. Your problem looks
'analog', check the character blanking is working, then check the digital
to analog, deflection etc.

When you hit the erase what happens ?

-pete

On Wed, Sep 21, 2016 at 12:07 PM, Mattis Lind <mattislind at gmail.com> wrote:

> I took a look at the Tektronix 4051 that we got a few years back. After
> checking the PSU I turned it on and it seemed to start up fine. The machine
> responded well to the keypresses but it was hardly readable on the screen.
>
> Anyone that can give advice on what is wrong and how to deal with it. The
> text on the screen is very faint and many characters are scrambled as if
> the beam was moving when the points where plotted. When typing there is a
> flash of the beam which is then stored as the scrambled text.
>
> http://i.imgur.com/iQhQW67.jpg
>
> It probably reads "SYNTAX ERROR" something on the screen.
>
> My experience with DVST device is minimal. I used an old Philips storage
> oscilloscope many years ago but I don't remember the screen to be this
> dull.
>
> It seems like the storage system is not at full output. Unfortunately I am
> not getting a good understanding on how the DVST system works from reading
> the service manual. What is the purpose of the timers for cursor and
> character intensity?
>
> I am about to check all the voltages related to the display mentioned in
> the calibration section of the manual, but just in case someone directly
> recognize what kind of problem there is I would be much interested.
>
> /Mattis
>
>