On 12/19/2012 05:39 PM, David wrote:
?
On Wed, 19 Dec 2012 17:00:50 -0500, Bert Haskins
<bhaskins@...>
wrote:
>On 12/19/2012 02:34 PM, David wrote:
>>
>> Just to be clear, the STORE/NON-STORE button in
the top row all the
>> way to the right does not do anything either?
>>
>It slightly changes the horizontal calibration.
You mean it shifts the horizontal position a bit? That
makes sense
because 1 pole of the STORE/NON-STORE switch changes the
horizontal
position on the analog side to set it up for the digital
display. That
is independent of anything the digital side of the
oscilloscope does.
The other pole enables DSO mode in the kernel.
>> Make sure to check the position of the
STORAGE/READOUT INTENSITY
>> control just to the right of the CRT.
>>
>> Since the readout is completely missing in analog
mode but the analog
>> oscilloscope apparently operates, if the above
checks out, then I
>> would suspect the digital board is
malfunctioning. You are probably
>> going to need a service manual to proceed.
>>
>This is like the "readout toggle on off" except that
it is just off..
>doesn't toggle.
And the storage display never shows a trace because it
never
activates, right?
The readout toggle function on the 2230 only applies to
the readout
and not to the digital storage trace so it is possible to
disable the
readout but still have a digital storage trace visible
with one
control.
>So I guess I'll have to check that out in the manual.
The service manual has a whole procedure for checking just
the kernel
(page 6-8) which includes the microprocessor, clock, and
address latch
but you probably need another working oscilloscope to do
it and it is
only going to reveal if the kernel is working or should be
working. I
*think* it should be possible to diagnose it using the
2230 working in
analog mode two traces at a time.
On the other hand, checking the kernel is probably a very
good place
to start, after the power supply voltages, because a
malfunction there
could easily cause the problems you are seeing.
The problem could be as simple as an IC
Close!
or connector popping out of
its socket because of thermal cycling.
Sorry about the late reply:
While searching for the answer to this, I happened to touch the
probe
to one of the pins on one of the eproms ( CE I think ).
When the probe made contact, the 7-segment readout changed from
a "8"? to blank and the readout appeared.
Removing, cleaning the eprom and socket fixed the problem.
This was not one of the crappy TI sockets it is a Berg/Auget style
dual side wipe.
First time I've seen a problem in one of those.
