CRT Assembly

Remove the main deflection board Remove the main board holder Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review CRT safety in Bulletins Safety. Awarning Never use a grounding wriststrap until after discharging the CRT. Caution The neck of the CRT is easily damaged. Do not grab the neck of the CRT to remove it from the bezel. Remove the four mounting screws and carefully lift the CRT from the bezel. Place the CRT face-down on the...

Screen Voltage

Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review CRT safety in Bulletins Safety. Awarning Because adjustments are made from the rear of the computer, position a mirror to view the computer screen. Do not reach around the computer to adjust the controls. Note If you have replaced the main deflection board, you must perform the screen adjustments prior to performing other adjustments. If you have not replaced the main deflection board,...

CPUto Monitor Cable

Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review CRT safety in Bulletins Safety. Awarning Never use a grounding wriststrap until after discharging the CRT. 1 Disconnect the eight-wire video connector from connector J201 on the CRT video board. 2 Remove the screw that secures the video cable to the back of the CRT video board. Remove the video cable from the cable clamp. 3 Remove the screw that secures the video cable to the mounting...

Main Deflection Board

Loose Vacuum Tube Anode Cap Repair

Remove the anode cap Remove the CRT video i j board Remove the external power cable Remove the CPU-to- ' y - ' monitor cable Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review CRT safety in Bulletins Safety. Awarning Never use a grounding wriststrap until after discharging the CRT. 1 Disconnect the following cable connectors from the main deflection board 2-wire LED cable from J502 (Detach the LED cable from the back of the flyback...

Fuse Apple Rgb Display

Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review CRT safety in Bulletins Safety. Awarning Never use a grounding wriststrap until after discharging the CRT. Using a small flat-blade screwdriver, pry the defective fuse from connector F901 on the deflection board.

CRTVideo Board

Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review CRT safety in Bulletins Safety. Awarning Never use a grounding wriststrap until after discharging the CRT. 1 Remove the screw that secures the video cable to the cable clamp at the back of the CRT video board. 2 Remove the video cable from the clamp and remove the clamp from the CRT video board. 8-wire video cable from J201 5-wire, 7-pin cable from J202 6-wire, 8-pin cable from J203 4...

White Balance

Place The Raster Center The Bezel

Note Complete any necessary geometry adjustments before performing the white balance adjustments. 1 Turn on monitor power and let the monitor warm up for at least 10 minutes. 2 Use Display Service Utility to display the Full Black Screen. 3 Set the brightness control and the contrast control to maximum. GREEN, RED, and BLUE CUTOFF controls to minimum. DRIVE-RED and DRIVE-BLUE controls to midrange. SUB-CONTRAST control VR201 to midrange. 5 Adjust the SUB-BRIGHT control VR202 until you cannot see...

Geometry

Crt Monitor Screen Adjustment

Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review CRT safety in Bulletins Safety. Geometry position a mirror to view reach around the computer to adjust the yoke. Note Geometry adjustments may be necessary whenever you replace the main deflection board, CRT, or video board. Note Do not attempt yoke adjustments on this monitor. The factory settings require no adjustment.

Rear Cover

No preliminary steps are required before you begin this procedure. Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review CRT safety in Bulletins Safety. 1 Place the monitor facedown on a protective pad and remove the two case screws. 2 Separate the bottom of the rear cover from the bezel. 4 Press down about one inch from the outside edges of the bezel to separate the top of the rear cover from the bezel. 5 Place the monitor facedown on a...

Characteristics

Picture Tube 12-in. viewable diagonal screen 90 deflection angle black matrix-type dot screen Phosphor type P22 aluminized Spherical, antiglare surface Screen Resolution 51 2x384 lines 64 dpi Displays up to 256 colors with Macintosh Display Card 4 8 and 16.7 million colors with Macintosh Display Card 8 24 Scan Rates Vertical refresh rate 60.15 Hz Horizontal scan rate 24.48 kHz Rise and fall time 27 ns maximum Active Video 8.08 in. by 6.02 in. 205 mm by 153 mm Input Signals Video red, green, and...

Horizontal Center

Using the plastic screwdriver, adjust the H-CENT control VR503 until the raster is centered side to side in the display area. Note If you cannot center the raster, set the H-CENT control at midrange and perform the following steps. Note Perform the following steps only if you could not center the raster using the V-CENT and H-CENT controls. 1 Switch off the monitor and remove the rear cover. See Rear Cover in the Take Apart chapter. Using the plastic screwdriver, adjust the H-PHASE control...

Troubleshooting

The Symptom Charts included in this chapter will help you diagnose specific symptoms related to your product. Because cures are listed on the charts in the order of most likely solution, try the first cure first. Verify whether or not the product continues to exhibit the symptom. If the symptom persists, try the next cure. Note If you have replaced a module, reinstall the original module before you proceed to the next cure. If you are not sure what the problem is, or if the Symptom Charts do...

Screen Luminance

Important Readings from light meter models R77, L-248 and 246 differ. Please note which meter you are using before making adjustments. See Light Meter Setup. 1 Using Display Service Utility, display the All-White Screen. 2 Using the light meter and a two-inch plastic screwdriver, adjust the SUB-CONTRAST control VR201 until you get 30 foot lamberts 3 foot lamberts , which on the light meter is Model R77 23 on the bottom scale Model L-248 middle of the 10 scale Model 246 23 on the red scale...

Model R

Date Stamp

The R77 light meter is capable of reading luminance from 1 0 to 1,000 footcandles fc . Before you begin, remove the 10X multiplier plate Three scales are shown on the light meter Because display screen luminance typically ranges from 10 to 50 fc, take readings from the bottom scale only. To measure a display screen's luminance, 1 Set the scale switch to the bottom position to set up the 10-50 fc scale . 2 Place the lens against the middle of the screen and read the bottom scale. Note When the...