Resetting the Logic Board

Resetting the logic board can resolve many system problems (refer to Symptom Charts for examples). Whenever you have a unit that fails to power up, you should follow this procedure before replacing any modules. 2 Remove the battery from the logic board. 3 Disconnect the power supply cable from the logic board and then press the Power On button. (See Logic Board Diagram later in this chapter to locate the Power On button.) 4 Wait at least 10 minutes before replacing the battery. 5 Make sure the...

Chassis Latch

Before you begin, remove the top housing. Note The chassis latches mount in the internal chassis and secure the internal chassis to the external chassis frame. Use a screwdriver to push out the tab indicated in the illustration. Slide the latch forward and lift it from the chassis. Remove CD-ROM or DVD-ROM EMI shield Note Special cable routing instructions for Master Slave IDE configurations can be found at the end of this section. sure the EMI shield doesn't interfere with the CD-ROM drive...

Video Input and Output

The AV I O card (an optional build-to-order feature) supports video input and output of composite and S-video signals. The card supports input and output of NTSC, PAL, and SECAM video formats. The AV I O card accepts video from an external source and displays it in a window on the computer's display. The features of the video portion of the card include Video display in a 320 X 240 pixel window Pixel expansion for 640 X 480 pixel maximum display YUV format for digital video input A...

The DAV Connector

The AV I O Personality card has a digital audio video (DAV) connector. The DAV connector allows a PCI expansion card to access the AV I O card video input data bus and associated control signals. The PCI card can use the digital video bus on the AV I O card to transfer real-time video data to the computer. The PCI expansion card can contain a hardware video compressor or other video processor. The DAV connector is a 60-pin flat-ribbon connector located at the top edge of the AV I O card. A PCI...

Data Buses

The data buses on the Power Macintosh G3 Desktop include Narrow SCSI-1 The SCSI-1 chain transfers data at up to 5 MB per second. The narrow SCSI-1 chain supports up to seven internal and external SCSI devices. The Narrow SCSI-1 bus is used to connect the ZIP drive (if present) and any SCSI-1 hard drives. Ultra Wide SCSI-3 (provided on Ultra Wide SCSI card, which is optional) The Ultra Wide SCSI-3 chain can transfer data at up to 40 MB per second and supports up to three internal devices. This...

The Cuda Chip

Its function is to Turn system power on and off Manage system resets from various commands Maintain parameter RAM (PRAM) Manage the Apple Desktop Bus (ADB) Many system problems can be resolved by resetting the Cuda chip (see Symptom Charts for examples). Press the Cuda reset button on the logic board to reset the Cuda chip. (See Logic Board Diagram later in this chapter to locate the Cuda reset button.) If you continue to experience system problems, refer to...

Ultra Wide Scsi Pci Card

The ultra wide SCSI card installs like any other PCI card (see the PCI Cards take-apart topic for more information) however, the ultra wide SCSI card must be installed in the first PCI slot (that is, the PCI slot nearest the video card). In addition, the ultra wide SCSI cable must be routed in a very specific manner. The procedure for installing and routing the ultra wide SCSI cable is explained on the following pages. 1 Attach the end of the ultra wide SCSI cable that has just one connector to...

Peripherals

2 Inspect inside of mouse for buildup of dirt or other contaminants. Clean mouse if necessary. Note The mouse contains a ball and several rollers that must remain clean. If either the ball or rollers are dirty, the mouse might not track properly. Refer to Tech Info Library article 6491 How To Clean A Mouse. 3 If mouse was connected to keyboard, connect mouse to computer ADB port instead. If mouse works, replace keyboard. 5 If mouse does not work in any ADB port on computer, replace mouse....

Verification Procedure

Follow the procedures in the Take-Apart chapter to access the power supply. IMPORTANT For all the following steps you will want to leave the power supply connector plugged into the logic board during testing. 1. Plug in a known-good power cord into the back of the computer. Note Do NOT power on the computer. Note For the next steps, refer to Figure 1 on the next page to 2. Connect the black lead of the voltmeter to pin 16 of the power supply connector. Connect the red lead of the voltmeter to...

About Your Optional Power Macintosh Audio Video Card

Video Input Port

The information in this update describes the additional capabilities of Power Macintosh computers that are equipped with an optional Audio Video AV card. For more information on setting up or using your Power Macintosh computer, see the setup manual that came with you computer. In addition to the standard sound input and output ports, the Power Macintosh AV card provides additional sound input and output capabilities through RCA-type connectors. These connectors are found on devices such as...

Floppy Drive

1 Replace floppy disk with known-good disk. During system startup, disk ejects display shows icon with blinking X 1 Replace disk with known-good system disk. Switch off computer. Hold down mouse button while you switch computer on. Replace floppy drive cable. Replace floppy drive. Drive attempts to eject disk, but doesn't 1 Reseat floppy drive bezel and drive so bezel slot aligns correctly with drive. Internal floppy drive runs continuously 1 Replace disk with known-good floppy disk. MS-DOS...

Fire Wire Technology

This section explains what FireWire technology is and gives specific information on Apple Computer's FireWire card, which ships as an optional build-to-order module on the Power Macintosh G3 Desktop. FireWire technology refers to Apple Computer's cross-platform implementation of the high-speed serial data bus defined by IEEE Standard 1394-1995 that can move large amounts of data between computers and peripheral devices. A digital interface - no need to convert digital data into analog for...

Exploded View

Rom Blow Diagram

Floppy Hard Drive Chassis Bracket 922-1657 Floppy Hard Drive Chassis Bracket 922-1657 Product family configurations may vary. Jumper Block Kit 076-0716 233MHz 076-0717 266 MHz 661-1302 076-0737 300MHZ Product family configurations may vary. Power Macintosh G3 Desktop Screw Matrix PCI Covers 1 ea 3 Power Supply Case to swing Chassis 1 2 on rear side of Power Supply Total 3 PCI Cards 2 Floppy Drive to Carrier 4 CD-ROM Drive to Carrier 4 Zip-Drive to Carrier 4 Hard Drive Bracket to Chassis 2 Logic...

Processor Module

Macintosh 6200 Processor

1 Remove the screw that holds the processor module wire to the logic board. processor module wire attaches to the top of the logic board not underneath . When screwing down the wire, be careful not to damage the capacitor that is next to the screw hole. Use a manual screw driver to avoid damaging the capacitor. Warning The heat sink may be hot to the touch. 2 While pressing down on the top of the clip that secures the heatsink, use a small flatblade screwdriver to lift up on the front tab of...

SGRAM Video Memory

The Power Macintosh G3 logic board comes with 2 MB of Synchronous Graphic RAM SGRAM video memory soldered on. The logic board also contains a video memory expansion slot that accepts a Small Outline DIMM SO-DIMM to increase video memory up to a maximum of 6 MB. Apple supports a 4 MB SGRAM SO-DIMM that is 32-bit wide, 144-pin, fast-paged, 83 MHz 12 ns cycle time or faster. Important Use only SGRAM SO-DIMMs. Never use the 256K or 512K video memory DIMMs used in older Macintosh computers. The...