On Sun, 12 Aug 2018 13:51:55 -0700, you wrote:
Hi Harvey,
Thanks for your email. It was very helpful. I was working with the scope
for a while, turning it off and on a few times, and finally the screen came
up. I suspect that since the scope hadn't been powered up in a long time,
it might take a while to initialize, and it seems fine now. Thanks very
much. I appreciate your help. Now I have two more Tektronix scopes to fix,
and one could be a project.
That it *didn't* come on immediately suggests that there may be a
problem that is waiting to happen. It depends on where the potential
problem might be, mostly, in such scopes, it goes into two causes: one
being a bad power supply, the second being the capacitors going bad.
When they do, they leak electrolyte and start to damage the PC board.
I'd suggest a search of your scope model to see if others have noted
that it's in the suspect years/models for such a problem.
I have a TDS540A, and it is a candidate for bad capacitors.
Harvey
Tom
On Sun, Aug 12, 2018, 9:22 AM Harvey White <madyn@...> wrote:
On Sat, 11 Aug 2018 20:31:33 -0700, you wrote:
All the lights ought to come on, then the power up sequence starts.
You should hear relays clicking, and you should see different lights
on the front panel. If not, then you have a possible power supply
problem, or a possible processor problem. There are diagnostic modes
that you should be able to use to check out the processor.
However, another possibility is that the display has failed. If so,
then you can plug in a computer display to the scope and you should be
able to see something. I'd do that first, then check power supply
voltages, then check the processor, etc.
Harvey
On Sat, Aug 11, 2018 at 8:27 PM Thomas Dodge <tdodge2404@...>
wrote:
Hi,
My name is Tom, and I haven't sent any emails in a while. I just bought
a
Tektronix TDS 648A scope. I plugged it in for the first time, and all
the
lights come on, but no intensity at all. Does anyone know how to
approach
this issue? Thanks a lot.
Tom
