PowerBook 160 Troubleshooting

PowerBook 160/180 rear panel, with the reset and interrupt buttons at the right (Apple developer note, Figure 1-3)

Fault-finding on the PowerBook 160 uses Apple's symptom charts for the 160/165/180 series, which work at module level. Try the cures in the order listed, test after each, and refit the original module before trying the next. The charts also cover the 165 and the active-matrix 180. Many 160s found today need their LCD and inverter recapped before the video charts are any use; see PowerBook 140 Capacitor Replacement Guide.

Before you start

• Test the adapter: 7.5-7.9 V between the inside (positive) and outside of the plug, on a meter's 10 V DC range.
• Test the main battery: below 5.7 V, recharge it first and replace it if it does not recover.
• Reset the power manager when battery and adapter are good but the machine will not start or restart. First remove the adapter and battery for 3-5 minutes, refit them and switch on. If that fails, remove them again for 3-5 minutes and then hold the reset and interrupt buttons on the back down together with two paper clips for 5-10 seconds before refitting and switching on.
• Check the backup battery: set the time, shut down, remove the main battery and adapter for ten minutes, and switch on again. If the time is lost, leave the machine on the adapter for 48 hours to recharge the cell, and replace it if that does not work.

Power

Symptom	Probable cause	Action
Blank screen, no response	Battery; power manager; connections; keyboard; boards	Apple's order: restart; connect the adapter and restart after 3-4 minutes; try a known-good battery; check the interconnect board, daughterboard and motherboard connections; reset the power manager; replace the keyboard, interconnect board, daughterboard, motherboard
Settings lost after removing the main battery	Backup cell; cables; interconnect board; boards	Check cables; replace the interconnect board, daughterboard, motherboard. Test the backup cell first as above
Battery desk accessory does not show the charger	Normal with a full battery; connection; battery; adapter; thermistor cable	Apple notes this is normal when the battery is fully charged; otherwise check the charger connection, try a known-good battery and adapter, check the battery thermistor cable, replace the motherboard
Runs on the adapter, not on a good battery	Battery contacts; fuse; motherboard	Reseat the battery; replace the removable fuse on motherboards that have one; replace the motherboard
Intermittent shut-downs or failed boots	Worn DC jack	croissantking found failing jacks on several 140-180 machines and replaces them as routine

Startup

Symptom	Probable cause	Action
Eight-tone error chord after the startup chime	RAM	Reseat and check the PSRAM card; replace the card, the daughterboard, the motherboard
Eight-tone chord only with a RAM card fitted	Wrong or faulty card	Apple's minimum RAM speed for the 160 is 85 ns. Wawavoun's 160 failed with a card using 100 ns chips, and his daughterboard reported only 2 MB of its 4 MB, which pointed to a faulty board
Four-tone error chord	Drive or motherboard	Disconnect the hard disk cable and restart; if normal, reconnect and retest, then replace the drive. Repeat with the floppy cable. Then replace the motherboard
Checkerboard, no chime	RAM card; daughterboard; display cable	Reseat and replace the RAM card; replace the daughterboard; reseat the display cable

Video

On the 160 and 165, Apple treats a thin white line across the middle, rainbow colours at extreme angles, uneven brightness and a display that fails below about 5 °C or above 40 °C and recovers as normal. Owners add ghosting around window edges to that list.

Symptom	Probable cause	Action
Blank grey screen, backlight on, machine runs	Leaking LCD capacitors	3lectr1cPPC's diagnosis for this symptom: recap the LCD
Picture visible only at a steep angle after an LCD recap; contrast slider washes it out	Inverter capacitors	DaveW cured this by replacing the inverter's 33 µF and 47 µF capacitors
Picture fluctuates between nearly right and washed out after a recap	Poor joints, leftover electrolyte, dirty contrast control	j2theLj redid a first recap whose joints were poor; 3lectr1cPPC also suspected a dirty contrast potentiometer
Contrast usable over only a few millimetres of slider travel	Worn or dirty contrast control	Shaddam IV's 160 showed this, and he set out to clean the slider. 3lectr1cPPC suggested contact cleaner on the slider for a similar fault on a 145
Row or part row never on (white line)	Cables; display cable; display; interconnect board	Check cables; replace the display cable and display; replace the interconnect board. Apple: on a 160 or 165 with a serial number below FC247xxxxxx or CK247xxxxxx, replace both the display and the daughterboard (but not a Rev. B daughterboard)
Row or part row always on (black line)	Cables; display cable; display; interconnect board	Check cables; replace the display cable, display, interconnect board
Flicker, two black lines, picture going dark	Display cable contact	If squeezing the right side of the bezel changes it, fit Apple's shim to the display cable
Very light or white picture	Contrast; connections; inverter; interconnect board; cable; display; boards	Adjust contrast; check connections; replace the inverter, interconnect board, display cable, display, daughterboard, motherboard
Backlight does not light	Pinched or cut cables; inverter; inverter cable; boards	Check the cables are not pinched or cut; check connections; replace the inverter, inverter cable, interconnect board, display cable, display, daughterboard, motherboard
Screen goes blank	Sleep; display cable; daughterboard	Press a key; check the display cable; reseat and then replace the daughterboard
Polariser darkening or blotching after storage	Polariser breakdown (vinegar syndrome)	mitchW's 160 developed it after two years in storage; the remedy is new polariser film

Drives, keyboard and peripherals

Symptom	Probable cause	Action
Internal hard disk does not work	External SCSI devices; cable; driver; drive; motherboard	Disconnect external SCSI devices; check the cable; reinitialise with HD SC Setup; replace the cable, drive, motherboard Original Conner and Quantum drives are now unreliable, and non-Apple SCSI drives need a third-party formatter
Floppy initialisation or read and write errors	Media; missing inverter shield; cable; drive	Try a known-good disk; fit an inverter shield if absent; check and replace the cable and drive
No response from any key	Power manager; keyboard and interconnect connections; keyboard; boards	Reset the power manager; check the keyboard to interconnect and interconnect to daughterboard connections; replace the keyboard, interconnect board, daughterboard Broken wires in the interconnect board's flexible cable also kill keys
Cursor does not move with the trackball	Connections; trackball; keyboard; boards	Restart; check cables and connections; try a low-power ADB mouse and, if it works, replace the trackball or keyboard; replace the interconnect board, daughterboard, motherboard
No sound from the speaker	Volume; external speaker plugged in; connections; boards	Set the volume above 0; unplug any external speaker; check the speaker, interconnect, daughterboard and motherboard connections; replace the interconnect board, daughterboard, motherboard

Related pages

• PowerBook 160
• PowerBook 160 General Maintenance
• PowerBook 140 Capacitor Replacement Guide
• PowerBook 140 Battery Replacement
• PowerBook 140 Troubleshooting#Power adapter