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Powerbook 145B

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The Macintosh PowerBook 145B was one of Apple's early laptops in the Powerbook 1xx line. It was introduced on June 7th, 1993 and discontinued on July 18th, 1994.

System Specifications[edit | edit source]

CPU Motorola 68030 @ 25 MHz Soldered to CPU Card
FPU None
RAM 4 MB 100ns PSRAM Soldered to CPU Card.
Upgradeable to 6 or 8 MB using a single 2 or 4 MB 70 pin proprietary memory card plugged into CPU card.
HDD Internal 40 or 80 MB SCSI Internal drive type is 2.5" 40 pin SCSI, which was not a commonly used standard.
FDD 1.44 MB 3.5"
Display 9.8" 640x400 Monochrome Passive Matrix STN LCD Display
Expansion Slot Optional 2400 Baud Modem Internal module plugged into main logic board.
Expansion Bay N/A
Keyboard Integrated 63 key No numeric pad.
Mouse Integrated trackball with two buttons
Ports Serial, Printer, Speaker Out, Microphone In,
ADB, HDI-30 SCSI, RJ-11 Modem (Optional)
Battery 1 x 2800 mAh Nickel Cadmium Battery These batteries are prone to leaking and should be stored outside of the unit when not in use.
Original battery packs are going to have long since expired and should be serviced/rebuilt before use.
PRAM Battery 1 x 3.0 Volt VL-3220 Soldered to 820-0411-02 board inside the laptop screwed to the back of the upper case half.
This is a rechargeable battery, DO NOT substitute with a normal CR type non-rechargeable battery.
Power 7.5 Volts @ 2.0 Amps Barrel connector is center positive. The OEM charger is known to suffer from capacitor failure, check its output before using it.

Known Issues[edit | edit source]

Like with anything, vintage computers have issues associated with them, the PowerBook 145B being no exception. Many of these are age related, but some are original manufacturing defects, and others can be caused by neglect. The PowerBook 145B was one of Apple's better laptops, but the machine can have serious issues if preventative maintenance and care in storing the machine are lacking.

The most common types of damage typical with older Apple Macintosh computers are leaking capacitors, leaking PRAM batteries and with PowerBooks, leaking main batteries. This damage is often caught far too late due to such machines being stored in attics, basements, sheds, etc. and long forgotten about by the original owner. Eventually such machines will be rediscovered during events such as moving, cleaning or estate sales, but the damage done by leaking capacitors and especially batteries has long since happened. You just have to hope that the machine was stored in such a way to minimize the effects of damage done so the device can be repaired.

The most destructive types of damage that can occur in older Macintosh machines are colloquially known in the vintage Macintosh community as "battery bombs", where the Parameter RAM (PRAM) battery casing fails and leaks its corrosive electrolyte all over the board and causes damage to whatever it touches. In PowerBooks, the Nickel Cadmium main battery can cause much more damage due to more batteries being present in the pack. And while the PowerBook 145B doesn't have the same type of PRAM battery used in desktop Macintosh models, it does have a rechargeable button cell battery that can leak and should be replaced as part of preventative maintenance.

Troubleshooting[edit | edit source]

Below is a table of some known issues with the machine and some potential fixes.

Problem Solution

Won't power on

  • Check the power adapter for correct voltage output, it should be close to 7.5 volts.
  • Check the barrel jack on the laptop with a multimeter for low resistance or a diode drop, which can indicate a potential short somewhere inside the machine.
  • Check the barrel connector on the main logic board for bad solder joints, joint fatigue is common from plug/unplug cycles.
  • Check the power button with a multimeter to see if it shorts its contacts when pressed. Also check for bad solder joints.
  • Remove the main battery from the battery bay, as it could be bad and dragging down the main power rail.

Powers on and bongs, but no display

  • Check the contrast and brightness sliders on the lower right side of the screen to make sure they are set appropriately.
  • Remove and inspect the display inverter board (805-0397A or CXA-2010 if made by TDK) which is located inside the upper case half in the rear under the screen. Common failures are oxidized/damaged linear sliders or bad capacitors.
  • Using a multimeter, check the resistance of each slider via its two solder legs while sliding back and forth. If the resistance varies too much or has interruptions, try using contact cleaner and blowing them out. If you get an open circuit, replace them with equivalent value linear sliding resistors.
  • Using an LCR meter, or component tester, desolder and test the two capacitors on the board. On the TDK CXA-2010 inverter, C1 is 33uF @ 16V and C4 is 47uF @ 25V. Capacitance values should not vary more than +/- 20%, and ESR should not be more than about 4 ohms.
  • Set the contrast and brightness to about 50% and use a bright light at an angle to the screen and check for an image. If an image is visible, then the CCFL backlight tube is likely bad and needs to be replaced. To rule out the inverter board, very carefully probe the output with a multimeter in AC mode, you should read around 400 volts.

Powers on and bongs, but garbled display or
screen has white/black streaks

  • Capacitor failure inside the LCD panel assembly is usually the cause. Replace all capacitors inside the LCD panel assembly.

Powers on and plays "chimes of death" with sad mac and hex error codes

  • Reference the error code document here.
  • If the chimes of death happen with no display, you have multiple issues and need to get the screen working first before diagnosing further.

Keyboard doesn't work and/or stuck keys

  • Check the keyboard ribbon cable in the upper case assembly that plugs into the 820-0411-02 board to ensure it is seated fully and free of debris in the connector.
  • Check the ribbon cable for broken conductors.
  • Remove the 820-0411-02 board and check the keyboard cable connector solder joints for damage.

Trackball doesn't work or erratic movement

  • Twist the trackball retaining ring about a quarter turn to release it and lift it and the trackball out of the laptop. Use isopropyl alcohol on a q-tip and clean the three tiny ball rollers inside and reassemble. This process may need to be repeated a few times if the trackball base is very dirty.
  • Check the ribbon cable coming out of the trackball assembly to the keyboard for proper connection, and the ribbon cable for broken conductors.
  • Check the green secondary ribbon cable coming out of the keyboard to the 820-0411-02 board for breaks and proper connection.

Powers on, but displays disk with question mark

  • Missing/invalid boot volume. If the state of the machine is unknown, this could indicate hard drive failure. The Conner SCSI drives used in this machine are known to be notoriously unreliable.
  • Try creating a startup floppy, or the disk tools floppy from a System 7.1-7.5.5 installation set. You can run Apple HD SC Setup or Drive Setup to see if the internal hard drive is working.
  • If the hard drive has failed, an original replacement isn't a good option. Any drive you find will most likely be in the same condition. There are projects like BlueSCSI PowerBook Edition, SCSI2SD or an external SCSI hard drive via an HDI-20 to 25/50 pin SCSI adapter dongle.

Powers on, but displays disk with an X inside it

  • Invalid/incorrect boot disk type. The PowerBook 145B requires Macintosh System Software 7.1.x through 7.5.5.