Tektronix 4051 repair.
elson at pico-systems.com
Wed Sep 21 20:56:05 CDT 2016
On 09/21/2016 02:07 PM, Mattis Lind 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.
> It probably reads "SYNTAX ERROR" something on the screen.
Whoa! I think maybe some timing circuit has gone bad,
probably due to bad electrolytic capacitors.
You might just leave it on for a while and see if it gets
better. It also looks like some of the deflection drivers
may be bad, as it seems like the upper left quadrant is
partially working, the rest of the screen is just a bunch of
loops. It is also possible that the character generator ROM
has gone bad.
More information about the cctalk