Samsung 750s approx 5 yrs old, text is ok but video and jpg's are too dark. There are two adjusting 'screws' on the transformer but BOTH are for focus. The only other adjusting screws I can find are on the neck marked Yv Yh Yhc.
Here is a pic of the 2 adjusting screws on the transformer. The one on top cannot be turned.
Martik
I'v never come across a LOP transformer that has TWO focus adjustments. Maybe you have a fault rather than needing adjustment. The bottom adjuster on the transformer is a bit like a 'threshold' adjustment refered to as 'A1' or 'screen' or 'final anode'. Adjust this till the screen is saturated then back off till the 'flyback lines' just dissapear. The adjustment pot on the tube base (neck of tube) will be gain or offset controls for the Red Green and Blue cathode drivers. Adjusting these may help but you'll need a 'grey scale' test card to get them right at all brightness levels.
Steve Balstone stephen balstone
The Samsung monitor has both an H and V axis focus on the HV multiplier for its dynamic focus control setup.
To adjust your monitor, you will need the Samsung PC interface and their software. The cost is a lot higher to buy this setup, than to take the monitor to a Samsung authorised service center and have them do the setup for you.
Jerry G. ======
Martik wrote:
check the heater voltage is not low. if its dc volts check the filter cap on that rail, had one like that years ago with leaky electro cap.
The red wire to the left of the flyback in your picture is the fixed G
2 supply. Check the G 1 voltage at the CRT socket, it should be marked. It shouldbe about - 40 volts dc, it is likely gone to about - 80 volts dc. Try a resistor from the G 1 connection to ground...about 47 kohms, up to about 100 k ohms. If you have no info on a certain monitor, this modification can bring your monitor close to a reasonable brightness range, with good results. Hope this helps, Dani.
Martik wrote:
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