The display fuzzy reasons and processing

The screen displays the ambiguity is one of the common faults of various displays, its causes has three main aspects:

1, Loose or shift during transport or use by the vibration leaving the FBT (line output transformer) focus potentiometer, resulting in added to the CRT focus voltage change (deviation from factory good debugging optimal voltage value), resulting in the screen vague;
2, the use of environmental humidity, so that the the focus pin CRT tailstock board discharge ring (half ball) rust, CRT powered blurring;

3, CRT tube internal manufacturing process or CRT pyramidal glass bulb debris of focus (focuse) pole and accelerating electrode (G2) between electrostatic dust, the formation of polar resistance of the screen is a serious blurring.

How to judge according to the a fuzzy screen the phenomenon is what causes it?

The first look at the degree of blur screen blur lighter, only the character outline thicker, and the writing was still able to identify, caused mostly the first reason; seriously obscure character large area, the screen is a white halo The character has been unable to identify and screen brightness changes, is a third reason for the tune focus potentiometer on FBT; the CRT just-machine vague with time increasingly clear screen character, which is usually for a second reason.

Clear screen vague reasons, and how to troubleshoot it based on the failure phenomenon?

In the first case, open the cover, the potentiometer to fine-tune the FBT Focus (focuse) troubleshooting. As for the the tail board Focus the pin discharge ring rust processing, general use the anhydrous alcohol cleaning discharge ring and tailstock electrode plugs and sockets, as serious ring rust discharge, replacement of the tailstock components. The third cause the screen fuzzy approach: remove the the CRT the tailstock board, CRT on the high hat 24KV high voltage with a multimeter pen line (best to use better insulation performance digital multimeter) lead to the CRT focusing plate socket turn on the monitor to AC power, and 2 to 3 times with a grounded table pen line on the accelerating electrode (G2) plug instantaneous discharge (preferably on a CRT G2 plug with an external protection sleeve short lead out lead line on the instant discharge operations).

Generally after 2 to 3 times of the discharge process, it will cause the focus (focuse) and accelerating electrode (G2) electrode resistance between the two electrodes of the dust breakdown. After the restoration of the original circuit, the clarity of the observation screen character or graphic display, if necessary, appropriate adjustment to the focus potentiometer on FBT can make the fuzzy troubleshooting. This method often called "the fight Acking Law, it comes to high-voltage operation, should be careful, remember to protect the safety of personnel and equipment.

Described above screen display fuzzy fault, not including those improper pole (G2) voltage regulator, brightness, contrast potentiometer adjustment position does not fit the screen caused by disorders such as acceleration, seem layer of fog Meng Meng feeling the situation is taken into account. For monitor IBM 2248/G03, Envision/D350, aligned with the middle part of the CRT screen gently with a rubber hammer hitting several five percent certainty exclude such displays of fuzzy fault This is certainly fuzzy failure shortcut road repair monitor .
source: http://www.pcpartsltd.com/blog/the-display-fuzzy-reasons-and-processing/