PowerBook 5300 General Maintenance

PowerBook 5300cs with the keyboard removed, showing the RAM card (Rama, Wikimedia Commons, CC BY-SA 2.0 FR)

Care and preventive work for the PowerBook 5300 series (5300, 5300cs, 5300c and 5300ce) and the PowerBook 190 and 190cs, which share one case, battery, expansion bay and Service Source. Apple's procedures here come from the PowerBook 190/5300 Series Service Source and the 1996 Repair Extension Authorization (REA) manual.

Before opening the machine

Warning: Apple's Service Source says the 190/5300 series contains the highest voltage of any PowerBook. Remove the battery and unplug the power adapter before starting any take-apart.

• Tools Apple lists: T-8 Torx driver, 2.3 mm jeweller's screwdriver, T-6 Torx for the floppy drive, T-10 Torx for the hard drive bracket and a #00 jeweller's screwdriver for the speaker. The REA manual adds an ESD-safe work station and wrist strap and a chip puller for the keyboard and trackpad cables.
• Route every cable exactly as it came out, using the grooves and guides. Apple warns that a misrouted cable can stop the machine closing up or working afterwards.
• Note where each screw goes; the screw types are easy to confuse. Apple's screw kit is 076-0639. Machines repaired under the REA program have some patchlock screws in the display, clutches and inverter positions.
• Do not overtighten screws into the plastics.

Batteries

Main battery

Production machines use a NiMH PowerBook Intelligent Battery, rated for up to 2.5-4 hours. The 5300 was designed for a 16.8 V lithium-ion pack, which Apple recalled in September 1995 after two caught fire while charging; see PowerBook 5300.

Apple's check with a meter set to read 14 V DC: a full battery measures 14 V, a flat one 7.8 V. Apple's handling rules:

• Do not leave a battery in the computer for more than a week without the adapter connected.
• Keep the contact cover on a battery that is out of the computer.
• Store batteries somewhere cool and dark, and recharge them at least every six months.
• Discharge the battery fully and recharge it once every 90 days.
• Fully charge a replacement battery before use.
• Fit the battery before connecting the adapter.

To remove the battery, push the button and slide the latch to the side, then pull the battery out. Old packs leak. One owner found traces of electrolyte in the battery compartment and a corroded pin on the battery connector, which has five contacts. Clean any leakage off the contacts and connector; see Battery Explosion, Capacitor or Corrosion Damage.

Lifting the backup battery out of its pocket in the CPU stiffener (Service Source, PDF p. 123)

Backup battery

The backup battery keeps the PRAM and power management data while the computer is shut down without its main battery. It sits in a pocket in the CPU stiffener and is Apple part 922-1418. Its cable plugs into the power supply board on the 5300 and into the logic board on the 190.

Apple's check: set the date and time, shut down, remove the main battery and adapter for ten minutes, then reconnect and switch on. If the date and time are lost, the backup battery is dead or flat; leave the machine plugged in for 48 hours to recharge it, and replace it if it still fails.

To reach it, remove the main battery, floppy drive, keyboard, RAM card, clutch covers, palm rest, hard drive and, on the 5300, the power supply board. When refitting, route the backup battery cable through the prongs on the CPU stiffener and under the notch in the hard drive bracket before screwing the bracket down.

Power adapter and power jack

Apple's adapter test: with the adapter plugged in, put the positive probe on the inside of the plug and the negative on the outside. The reading must be 21.6-26.4 V; Apple warns not to use these figures for any other PowerBook adapter. Low End Mac gives the adapter part numbers as M3747 or M3037.

The power jack on the logic board is the first suspect for a machine that loses power when the cable moves. Apple's chart says to check that the connector pin is not bent and that the connector is not loose, and to replace the logic board if it is; the REA program listed a loose or inoperative AC connector among its symptoms. Owners repair the jack instead. It is held to the board only by its three through-hole joints; one owner reflowed them, added solder on the top side and glued the jack to the board, and another resoldered it with fresh solder.

Resetting PRAM and the power manager

Apple's procedure, from the shut-down state (it also resets the power manager):

1. Unplug the adapter.
2. Press the power key and immediately hold Option, Command, P and R.
3. Keep holding them until the startup chime has sounded at least once more. These machines often chime only once, after which the screen goes dark and the green sleep light stays on without blinking.
4. Press the reset button on the back once; the machine should start. If the sleep light stays solid green, press reset again, or start the machine with the power key.
5. Shut down from the Special menu and plug in the adapter. If the computer stays off, the reset has worked. If it switches itself on, reset the power manager.

To reset the power manager on its own: remove the battery, unplug the adapter from the computer and the wall, hold the reset button for one minute, then reconnect the adapter. If the sleep light is on continuously and the machine will not start, Apple's first step is to hold the reset button for 10-20 seconds, repeated three or four times if needed. Resetting PRAM erases any RAM disk and returns most control panels to their defaults.

Case, hinges and display

The REA program existed partly because the plastics crack; it replaced display bezels and housings, palm rests, centre clutch covers, CPU stiffeners and bottom cases. Apple's precautions:

• Do not tilt the display back more than 170 degrees from the keyboard; further than that can damage the CPU stiffener.
• Overtightening the lower two bezel screws cracks the bezel. After fitting them, open and close the display; if it creaks, loosen the screws.
• After refitting the display, try to slide a 3.5-inch floppy disk between the closed display and the top case. If it goes in, Apple's note calls the clutch screws "undertightened" and says to remove the display assembly and loosen the screws.
• To remove a clutch cover, set the display at 170 degrees, pull up from the seam in the back plastics with a fingernail, rocking the cover until it releases, then lift it straight up clear of the display. Fit the palm rest before the clutch covers.
• Route the display cable over the pegs on the left clutch, not under the screw.
• The connectors on the inverter board are fragile, the microphone cable most of all; lift the board carefully, as four cables are attached on three sides.
• The display cable connector on the logic board sits next to the fragile PC switch board connector; lift the cable by its hardened backing, working from the side away from the PC switch board.

Lifting the clutch covers with the display at about 170 degrees (Service Source, PDF p. 96)

Display ribbon cables that fail at the hinge give vertical lines or a dead screen; see PowerBook 5300 Troubleshooting.

Keyboard, RAM card and trackpad

To remove the keyboard: close the computer, turn it over and remove the three screws from the bottom; open it, lift the keyboard slightly up and towards you until you feel resistance, and stop there, because pulling further tears the keyboard cables out of their connectors. Rotate the keyboard onto the palm rest and lift the two cable connectors by their ears with a flat blade. A foam gasket (922-3103) on the bottom of the keyboard holds the RAM card down; fit one if it is missing.

Lift the RAM card straight up by its near corners, supporting the corner over the connector. A card that is not seated properly can stop the machine booting, and a card with a bad memory chip can stop it completely.

Clean the trackpad only with the computer off, using a material that does not build up static. Apple's note on erratic cursor movement says the pad must be touched with one finger at a time.

Expansion bay and hard disk

Expansion bay modules need about 7 lb of pull to remove; the bay's tolerances are tight, so line modules up carefully before pushing them in.

The internal drive is a 2.5-inch IDE disk. To remove it, take out the battery, floppy drive, keyboard, RAM card, clutch covers and palm rest, then the three screws holding the drive bracket to the CPU stiffener. Lift the bracket only until you feel resistance, because the drive cable is still connected on the left; turn the bracket over to the left and unplug the cable by its hardened backing. When refitting, check that the drive's EMI shield and insulator and the heat sink leaf spring are in place. Low End Mac warns that the drive controller in pre-G4 PowerBooks does not work with ATA-6 (Ultra ATA/100) drives. See Hard Drive Maintenance and Repair.

Capacitors

The 5300's power supply board carries twelve electrolytic capacitors and the 190 has eight on its logic board; the displays and inverter board have more. Values are on PowerBook 5300 Capacitor Replacement Guide.

Preventive checklist

1. Take out the main battery; check it, its connector and the bay for leakage, and measure it against Apple's 14 V and 7.8 V figures.
2. Check the backup battery with Apple's date-and-time test.
3. Measure the adapter (21.6-26.4 V) and check that the plug sits firmly in the jack.
4. Open the display no further than 170 degrees and inspect the bezel and hinge area for cracks.
5. Check the RAM card is seated and the keyboard gasket is present.
6. Back up or replace the original hard disk.

Related pages

• PowerBook 5300
• PowerBook 190
• PowerBook 5300 Troubleshooting
• PowerBook 5300 Capacitor Replacement Guide
• PowerBook 5300 and 190 Repair Extension Program
• Battery Refurbishment