Hameg HM412-5 Oscilloscope problem

[DarkZero]

Hey guys

The other day i went to the old stuff market and saw this oscilloscope for 20 euros and the guy said it worked and i took the gamble and bought it. When i got home i hooked it up and it worked indeed, so i played with it for a couple of days to see if anything is wrong with it but guess it was working just fine.  but yesterday when i was playing with it suddenly i lost the line on the screen and i thought it died but then i looked at it better there was still a line but it is very very fade i tried turning the intensity and focus knobs but it had very little effect on it, it is still hard to see. So i opened it up to check if anything burned by the looks i found nothing, next thing i planed to re-solder the things around the CRT then ill check voltages coming out of the transformer. Well that's as good as i can do if any tips or help would be awesome also ill attach Schematic of the thing  maybe someone will get some idea what to check or do

link to the service manual http://www.hameg.com/typo3conf/ext/hm_downloads/pi1/download.php?uid=5291

thx in advance

[w2aew]

My first guess would be that you lost the acceleration voltage for the CRT.  The manual says that this is -1900Vdc.  If you don't have a suitable probe and meter to check this SAFELY, then you're better off having someone else look at it. It can be VERY dangerous if you don't have the right high voltage equipment.  If you have the right equipment, then I'd start with checking the operating voltage listed on page 32 of the manual.

[DarkZero]

well its one of the reasons i didn't check the voltages on the CRT because my multimeter goes to 1kV. Guess that fixing it is beyond my possibilities. Well i guess ill check parts along the line of that -1900Vdc maybe i get lucky until i gather money for repairs.

thx for the answer atleast it narrowed the problem