I have not worked on this model of scope, but I can maybe give some
suggestions.

Check that the main power supply is working to specs. Then check that
the high voltage and focus supply are to specs.

Because you are saying that the display is sort of dim on one side
compared to the other and there is soft focus, this is a possible
indication of voltage regulation, and switching power supply DC
filtering problems at its outputs.

Some scopes that I have worked on had high voltage modules that supply
the anode and focus supply. I have had the module go defective causing
your described fault.

The last alternative if you feel it is worth while, is to call the
manufacture and see if they would service the scope. Or, see if you
can find a working used one of the same model. This way, you may be
able to have some spare parts.


Jerry G.

__


On Jan 10, 1:35*pm, wrote:
Hi,

I'm currently having trouble with my good-ol' HM1005. It has some
problems focusing correctly.
When it's cold, you first see nothing on the screen. Increasing
intensity results in an almost completely glowing screen, looking like
an EL-backlight. Leaving it on for some minutes shrinks the glow more
and more to a spot (in X/Y mode) or to a horizontal line (in normal
operating mode). Now it's possible to use that thing, but it's not
completely working correct.
On the left side of the line the beam is more intense. I've made a
photo of that, please have a look athttp://www.preamp.org/dinge/hm1005.jpg.
Using a time base of 50ns shows some kind of overshoot next to that
bright spot. The trace is moveable to X and Y as it should (I did that
on the photo, so the bright spot is not on the grid).

I'd appreciate any kind of help that can lead me to the source of this
strange behaviour.

Thanks in advance and with best regards from Germany,

Lasse