What if the monitor image is blurry?

Sometimes our monitor will appear ambiguous situation, this kind of situation is more common, encounter this kind of situation, what should we deal with the malfunction of the monitor when we encounter the ambiguity?

The display of the content is ambiguous that the CRT focus is not good, resulting in poor focus on the main reason is the picture tube aging, or the anode high pressure is too low, or focus (focusing) voltage is incorrect. The inspection should be conducted in the following areas:

1, check whether the old picture tube, for the general maintenance, due to the lack of dedicated equipment, can only use indirect methods, the specific practice is:

The brightness potentiometer of the CRT is opened to the maximum, and the monitor is electrically added and the grating condition is observed. If the grating appears to be used longer and not enough brightness, then the picture tube aging, if the grating appears normal time (compared with the normal display), it shows no aging. Sometimes a slight leakage of the picture tube or a spark will also cause focus is not good, for the picture tube leakage inspection can be observed tube neck part, when found in the tube neck has "fog-filled" phenomenon, it shows that the picture tube leak. Check the cathode of the tube is a spark, you can directly observe the display of the screen, if the contents of the display although vague but very stable, the picture tube will not exist in the ignition. The failure was checked to show that the picture tube was undamaged.

2, high pressure meter can directly measure the anode high pressure. If no high pressure meter, can not use the multimeter directly to measure the anode pressure. The common methods are:

(1) to the monitor when the attention to listen to the deflection yoke has no obvious high pressure charging sound, if there is, general high pressure will not have much problem: if not, then the monitor does not have high or low pressure.

(2) to the monitor after the power to touch the screen with the hand, to see if there is no "pa" Electrostatic discharge sound. If there is, then the voltage is basically normal, if not or static discharge is not obvious, the monitor does not have high or low pressure. Failure to check the cathode tube anode voltage is basically normal.

3, check the focus voltage. Adjust the focusing potentiometer of the kinescope (on the output transformer), display content as clear as ever, the use of less than half a day, the phenomenon reappeared, after the inspection found that the focus of the potentiometer knob is fixed with silicone rubber, this rubber elasticity is very strong, the first potentiometer adjusted well, because there is no new fixed, after a period of time due to elasticity, Silicone rubber and the potentiometer pull back to the original position, so the phenomenon of recurrence, the potentiometer adjusted well and fixed with epoxy resin, the failure to completely eliminate.