Sony CRT Brightness Fix
Introduction
Many Sony Trinitron-based monitors manufactured around the 1999-2000 time frame develop a brightness problem over time which
substantially degrades the picture quality. Some models which exhibit this problem are the Sony G500 and the Dell P1110.
The following "fix" has helped me and many others get the brightness and color back to near factory specs. The main signs
that you have this problem will be the absence of a good black level - even with the brightness set to 0, the monitor will show
blacks as bright greys. [Disclaimer: this "fix" is not really the correct way to fix the problem, but the results should be
quite satisfactory.]
To remove the monitor case, turn it screen-side down and locate the (2) screws holding the back half of the casing to the front (they are located on the sides of the case). Once these screws have been removed, there are (2) plastic tabs, one on each side, that you need to pry loose. These tabs are sometimes stubborn, so apply a fair amount of pressure while pulling the back of the case away from the front. With the back casing off, your monitor should look like the following image:
Now you need to remove the RF Shielding (metal mesh) that is covering the circuit board on the rear of the monitor. There are a number of small screws around the edges of this shielding that just need to be removed. Once the shielding is off, you should be looking at the following image. Notice the red arrow drawn in the upper right hand corner of the board, this is the area we will be working with.
In the upper right corner of the circuit board, you should see a label "R459" between 2 solder points. The following image has been rotated 90 degrees clockwise from the previous image. The R459 resistor is on the underside of this board is relatively hard to get to, but you need to disable it by breaking the circuit. The best way I have found is just using a small pair of wire cutters to snip one of the resistor legs. Make sure the circuit is cleanly broken and not touching anywhere. For reference, the original R459 resistor is supposed to be rated at 10 MOhm. A number of people have left the R459 resistor intact and soldered an additional 10MOhm resistor in parallel with it, creating an effective resistance of 5MOhm. However, the math becomes a little more complicated when trying to vary your resistance value in this scenario.
You are going to need to buy a resistor in the 4.7-6.8 MOhm range (should cost about 20 cents). The exact resistor you need is dependent on the severity of the problem - but any value in this range should provide substantial improvement. The general consensus is the lower the resistance, the darker the result will be. Using the two existing R459 solder points, solder on your new resistor. After you are finished, it should look something like the following image:
Reattach the RF Shielding with the screws and then snap the back casing of the monitor onto the front. Replace the two screws you removed and you are finished. After turning it on, you will need to adjust the brightness and contrast controls because the monitor will be much darker (and you should have a nice black level). Return to article index