This 17″ CRT Relisys OEM Monitor came in with the grievance of dull showcase (can’t see back raster). Despite the fact that at the front board through the On Screen Display (OSD), you have acclimated to greatest the back raster actually would not show out and the entire showcase showed up very faint. Regularly at whatever point we see this sort of faint presentation issue we will go directly to the flyback transformer and change the screen (G2) voltage control to expand the voltage to the image tube so the showcase will become more brilliant once more.
Some way or another, in specific CRT Monitor plans, there is no screen (G2) control (handle) for you to change. It contains just the two handles for you to change the concentration (F1 and F2 handles). Since we can’t observe any G2 control at the flyback transformer, one would consistently look for interior preset splendor control however tragically this model doesn’t have one. It has just the B+ control and high voltage control preset. The high voltage preset has been stuck with silicon and we can’t just tune this preset if not the Monitor will irregularly go into closure mode. The main preset left for you to change is the B+ control. Indeed the facts really confirm that occasionally in specific Monitor you can adjust the B+ control preset to build the splendor however it isn’t prescribed because of the expansion of the B+ voltage will expand the Display Reparatur pressure of the even result semiconductor (HOT). The HOT may not keep going long and in some cases will blow in two or three hours.
In this Monitor, I attempted to change the B+ preset to check whether the brilliance would show up or not however the result made the showcase go more extensive and still faint. Assuming I keep on tuning the B+ control, I’m apprehensive the HOT might blow in an exceptionally brief time frame! This is only an analysis just, recollect that don’t tune the B+ control without a valid justification.
After the Monitor had been utilized for two or three years, the CRT cathodes (outflow) may have become powerless and this made the showcase go faint. To make the showcase to become more splendid once more, you can expand the radiator voltage from 6.3 volt to around 8 to 9 Volts. Or on the other hand you can change the G2 circuit to expand the voltage without tuning any B+ or high voltage preset in the Monitor. In this article I’m contacting just on the change of the G2 circuit.
Since the flyback transformer doesn’t have the G2 control in this manner we can’t follow from the flyback to search for the G2 wire. Indeed we can follow in reverse from the CRT board to see at where the G2 wire came from. Indeed it came from the Main load up and not from the flyback transformer. After turning around the Main board, one can undoubtedly see the little G2 circuit that contains a diode, high voltage capacitor and some extremely high ohm resistor.
This is the way the G2 circuit work. The high heartbeat AC supply came from one of the flyback transformer auxiliary pin and it go through a Ultra quick recuperation diode. The capacity of the diode is to change over the high ac beat into DC voltage and the high voltage capacitor (102 2kv-sap ceramic sorts) is to use to channel off the high recurrence wave and afterward the voltage course through the resistors and the resistors decides (set) the result voltage. When you see how this circuit work you can undoubtedly alter the circuit or change the worth of the resistors to make the G2 voltage increment.