I have a 4012 service manual, but it's so buried that I don't know if I can
located it. I'm going home next weekend, I'll take a look, if no one else
has one available and posts as such here.
Jim Davis.
Tony Duell wrote:
On Wed, Jan 03, 2001 at 11:44:57PM +0000, Tony Duell did utter:
IIRC, most Tektronix storage-tube terminals display a flashing cursor
(may be rather dim) in the top left corner after power-up. Are you
getting that?
Nope... the screen brightens - with a fuzzy circle in the center...
eventually he whole screen is bright. Nothing I've ever done yet has
affected this.
SOunds like the flood guns (part of the storage system) are working, at
least partially, but the writing gun might not be. Or at least might not
be turned on by the control electronics.
Alas I don't have the 4012 service manual, only the 4014 one. These
storage CRTs can be a little difficult to work on unless you're used to
them as well..
Also, isn't there a LOCAL switch or similar?
If there is, then the
keyboard is connected to the display section (and the RS232 port isn't
used) in LOCAL mode. So anything you type shoudl appear on the screen.
Yup, there is a [Local|Line] toggle on teh front, next to a power light
which doesn't appear to work, two LED's I've never seen light up, and three
I wonder if the power lamp is burnt out, or if there's a PSU fault.
more toggles (simply called 1, 2, 3)
What baud rate, etc, are you usimg, and do you
know that the terminal is
set for the same parameters?
There are a couple of nice big chunky knobs on teh back to set the transmit
and recieve baud rate (yes, independantly!) from 110 up to 9600. Also a
OK...
third knob with duplex settings. I have working
null modem cables... but
no luck.
There are three further adjusetments knobs on the terminal. Two on teh
front, one vertial and one horizontal (and labelled as such with arrows) - I
Those IIRC are a bit like a mouse -- you can read the positions over the
serial line. And thus use them as a pointing device.
assume these are crude focus or alignment
adjustments. There is also a small
dial on the side - I assume it might be brightness? In any case, none of
Probably brightness of the writing gun.
My next test would be to check the voltages on the logic boards -- at
least ensure that the +5V line and the +/-12V lines (for the RS232
drivers) are there. And then you need to find somebody with a service
manual and see what the wiriting gun is doing.
-tony