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kortek ki-2-vo brand chassis repair help - only high voltage
perjmolsen:
Hi
I have this Kortek ki-2-vo chassis that I am trying to repair.
I have checked the fuses they are all OK, also change a couple of caps because that looked bad, but where OK when I tested them.
Changed:
c610 47uf 160v
c612 22uf 160v
c706 10nf 250v
c703 470uf 25v
Tested OK
q702 D1399
d703 Diode
Fuses
When I power it on, I hear the normal static high voltage sound on the CRT, and I can also feel the static on the CRT
Nothing happens when I turn up the screen voltage.
I cannot see any neck glow, is that possible with high voltage?
I assume that my flyback is working because I can hear the static turn on sound, and also I get a big POP when i discharge the annode.
How do I tackle this repair? :notworthy:
Can I test for heater voltage by putting the red probe to the "H" on the neckboard? and netative to chassis ground
and the screen volt at the "screen" on the neckboard?
Or is there a better way?
princess prin prin:
The flyback generates the heater voltage (H) and the video B+ voltage (BH). They're on the header with the red/black/white wires running from the main chassis to the neckboard. You can measure H on the neck socket and ground. it's an AC voltage around 6V. BH is a DC voltage in the 180-200V range. If H is not present, check R706.
yotsuya:
Check the connection on the neck board. I had a monitor with similar issues, and the problem was with the connection from the fly back to the neckboard.
perjmolsen:
--- Quote from: princess prin prin on January 08, 2020, 05:42:31 am ---The flyback generates the heater voltage (H) and the video B+ voltage (BH). They're on the header with the red/black/white wires running from the main chassis to the neckboard. You can measure H on the neck socket and ground. it's an AC voltage around 6V. BH is a DC voltage in the 180-200V range. If H is not present, check R706.
--- End quote ---
Hi
I have tried to see if there is 6V AC Heater volt, on the "H" point at the neck socket (ground to chassis) = 0V
Tested R706, tests OK.
Also tested for DC B+ on BH, (ground to chassis) = 0V
So It must be a bad flyback then....?
perjmolsen:
--- Quote from: yotsuya on January 08, 2020, 08:41:16 am ---Check the connection on the neck board. I had a monitor with similar issues, and the problem was with the connection from the fly back to the neckboard.
--- End quote ---
Hi :)
I have re-solder the connections but still no luck