Tempest is slowly coming back to life - still need a little help

[Scott Caldwell]

OK, my Tempest cabaret project that I've posted about several
times here recently is slowly coming to life. I still need
a Tempest cabaret wiring harness if anyone has one (PLEASE!!!).
I could use the coin door or coin door wiring harness too.

As it sits now, I have one working boardset and two working
monitors, I believe. I'm also down to two problems, I believe,
but want to verify the problem is my working boardset or just
where to look.

- The X Center pot on the CPU PCB appears to have gone and
doesn't seem to do anything now. I'm assuming that is why I
can't move the image from the top of the tube to the center.
However, one of my WG6101 monitors has the image all of the
way at the top and even a little off the top, while the other
has the whole image on the screen and even a little from the
top. Obviously, nothing is different on the board, so is it
normal to have this "space" difference between monitors when
driven by the same boardset (with a broken pot)? I haven't
cross the part # on this pot, but assume it's a fairly
standard part I can get most anywhere.

- The second problem I thought was the monitor may very well be
the boardset, since both monitors do this. After the "Tempest"
words grow (in color) to their full size on the screen, the
monitor deflection collapses, but quickly returns with the
white colored "Tempest" fully displayed on the screen. One
one monitor the "T" in Tempest is angled a little, but looks
OK on the other. What on the Tempest PCB would be giving
out to cause this momentary collapse? Oh, the spot killer
does activate on the monitor (the red light is one!).

I did make sure my +5v is set right at +5v or +5.1v (measured
from the test leads on the aux PCB).

BTW, for those of you curious about how I solved the 2nd WG6101
monitor "looking" like it had no sync (yes, I know X/Ys have no
sync, but that's the best way to describe how the screen looked),
I disconnected the high-voltage and reconnected it. Evidentally,
the plugs were dirty and not making good contact. Strange, but
good to know.

Scott C.

[Mark (UK)]

Hiya!

The MC1495s can cause very funny things to happen to the display,
including non-working pots, collapse of one direction etc...

Yours, Mark.

[Scott Caldwell]

Mark, OK where is that little puppy, since I'm still new to
Tempest repair?

Scott C.

[Mark (UK)]

Hiya!

There are 4 of them, they are located in the vector generator area, near
the DACs and the twiddlepots...