Power mac 5500/250 image control

Question

We have a power mac 5500/225 being used in a classroom, the display image is fuzzy. I can not find a deguass or any other control that will sharpen the image. Any help?

Answer 1

The MiniDIN-8 to two-pin cable is called out by part number in the service manual, along with the procedure. I must have extracted it from that manual at some point, since I had this file hanging around:
On-Screen Video
Before you begin,
• Turn off virtual memory
• Turn off the power
• Remove the I/O door
• Remove the rear housing
• Discharge the CRT
• Remove the anode cap
• Disconnect the microphone cable
• Remove the rear EMI shield
• Remove the modem card (if present)
*Warning: This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review CRT safety in Bulletins/Safety.
*Warning: Never use an antistatic wriststrap until after discharging the CRT.
Note: The 5500 is made with Rev. B parts.
1 Remove the three Phillips screws that secure the analog board to the chassis.
2 Tilt the analog board back, being careful not to put stress on the cables.
3 Locate jumper P805 (Rev. A) or P102 (Rev. B) near the logic board connector on the lower left corner of the analog board.
4 Remove the shunt that covers the pins of jumper P805 (Rev. A) or P102 (Rev. B).
5 Note: It is very important to perform this step correctly according to the Rev. A or Rev. B instructions
• The square silkscreened marking at P805 (Rev. A only) indicates pin 1 on the analog board. For Rev. A, connect one end of the monitor adjustment cable (922-1513) to P805. Be sure to position the connector so the pin 1 opening is aligned over pin 1 (square marking) on the analog board.
• For Rev. B, connect one end of the monitor adjustment cable (922-1513) to P102. The arrow mark on the plug connector (see graphic) must go over the pin closer to the top of the analog board. Hold the connector with gold connectors facing you, and place the connector on the two pins at P102.
Important: The adjustment won’t work if the plug is incorrectly placed on the pins.
6 Connect the other end of the monitor adjustment cable (922-1513) to the modem port.
Note: You must use the modem port. Remove the internal modem and plastic modem port cover, if present.
7 Route the monitor adjustment cable so it stays clear of sharp edges and remains slack.
8 Reconnect the grounding screw to the EMI shield.
9 *Warning: Be sure to remove the antistatic wriststrap before replacing the anode cap. Replace the anode cap.
10 Position the monitor so you can see the screen.
11 Turn on the power.
12 Run Display Service Utility to display the on-screen video adjustment controls. The controls appear after selecting PowerPC 5200/5300/5400/5500 in the pattern selection box and then select adjust geometry.
13 Use the scroll bars to adjust the horizontal and vertical controls.
14 To cancel settings (and revert to the last saved setting) click Cancel.
Size
Position
Pincushion
Trapezoid
Size
Position
Vertical Controls Horizontal Controls
Display Service Utility
Resolution screen
1 of 5
15 To save your settings (in the monitor’s selected resolution) click Save.
16 Important: After you click Save or Cancel, the name of the next screen resolution appears at the top of the screen. You must set and save the on-screen video adjustments for each remaining screen resolution. Otherwise, if you change from a saved resolution to an unsaved resolution, the display will appear misadjusted. Set and save the settings for each screen resolution. After saving the last screen resolution, exit Display Service Utility.
Message was edited by: Grant Bennet-Alder