PowerBook G4 Titanium Mercury Troubleshooting
The first of the G4 powerbooks, the Mercury included a titanium case assembly and a 15.2" wide-aspect display. Troubleshooting is fairly straightforward.
PowerBook won't turn on.
Your computer will not boot.
PMU reset needed
If your laptop fails to start up, the first thing to try is to reset the PMU. The PMU reset button is located on the rear panel of the computer (behind the port door) between the video-out and modem ports. Use the tip of a pen to press the reset button for about 5 seconds and reset the PMU. After resetting the PMU, try booting the computer again, if you're lucky, you'll have a working machine again.
Bad power adapter or battery
If your power adapter is bad, the computer will run off a battery, but it won't charge. If your battery is bad, the computer may shut off immediately when the AC adapter is unplugged. The easiest way to test this is to borrow either a battery or power adapter to test in your machine.
Check our [/|online store] for compatible batteries.
Bad logic board
If your DC-in board is bad, you will not be able to start your computer when it's plugged into the wall. It will likely still work if you have a charged battery. The light on the power adapter will probably not light up at all. (Some power adapters do not have lights, so this may not apply to your computer.) Unfortunately, the DC-in board is integrated onto the logic board on the Mercury, so fixing a DC-in problem will require a replacement logic board. There are two different speeds of Titanium Mercury logic boards, both of which are interchangeable: 400 MHz and 500 MHz. We have free installation instructions to make installing your new logic board a painless operation.
Display backlight not working
Symptoms of this are a dark screen, but everything else seems to be running. If you get in close with a flashlight, you can usually see the image faintly.
The most likely cause of no backlight is a non-working inverter board. The inverter board converts DC power from the computer to AC power to be used by the LCD backlight.
If replacing the inverter board didn't fix the problem, it's possible the backlight in the display is defective. Since the display assembly is tightly glued together, its nearly impossible to replace just the backlight of the LCD. We do offer complete display assemblies as well as installation instructions.
Bad logic board
This is rare, but occasionally a bad logic board can cause the backlight or display not to work. There are two different speeds of Titanium Mercury logic boards, both of which are interchangeable: 400 MHz and 500 MHz. We have free installation instructions to make installing your new logic board a painless operation.
Flashing question mark on startup
The computer displays the flashing question mark when it can't find a bootable operating system. This could be because your OS is corrupt, the computer doesn't have enough RAM, or your hard drive is failing.
Bad Operating System
Try booting off an OS CD. Run Apple's Disk Utility and try to repair the disk. You could also try Alsoft's DiskWarrior. If this fails, reinstall your operating system. If you can, erase the hard drive prior to reinstalling the OS.
Not Enough RAM
This is very rare. If you don't have enough RAM for your computer to boot the operating system installed, you can get the flashing question mark. Installing more RAM or downgrading to an older operating system will fix this. This is not usually an issue unless you have 64 MB or less RAM and you're running OS X.
Bad Hard Drive
The hard drive may have been erased, corrupted, or damaged. If the hard drive has been erased, format it as HFS+ and reinstall your operating system back onto it. If it is corrupted or damaged, you need to replace it. Failing hard drives can display intermittent data corruption prior to failing completely. They often get louder gradually and start to click. If your hard drive is making abnormal clicking noises but still works, back up your data immediately and replace the hard drive. Any of [/Products/Titanium-Mercury/Hard-Drives/7/21|these] hard drives will work in your computer.
Display hinge is broken
The display hinge is physically broken and the LCD assembly will no longer stay upright.
Alas, hinges on the Titanium series were not made out of titanium. This oversight by Apple means that broken hinges are an all-too-common problem on Titanium PowerBooks. Hinge repair is one of the few installations best left to professionals. Apple glued the display assembly tightly together, making opening the display without damaging the thin metal casing very difficult. We do offer the much easier to install complete display assembly as well as installation instructions.
Latch is not holding the computer closed
The computer either fails to latch shut or latches and then pops open.
Worn latch assembly in upper case
The Titanium is held shut with the combination of a hook extending from the display assembly and a catch in the upper case near the trackpad. Over time, the hook often wears away the metal catch, preventing the hook from latching the computer securely shut. If the catch in the upper case is worn, you can simply replace the latch.
Broken or damaged latch hook in display assembly
If the latch hook that is located at the top of the display assembly is damaged or broken, there's no easy way to fix the problem. An improvised latching mechanism such as a rubber band may be your best bet. If you know what you're doing, you can attempt to take apart the display assembly and fix the problem. This route is not recommended unless you know exactly what you're getting into.
Paint is chipped or peeling off case
The paint is flaking or chipping off the Titanium case.
Poor quality paint
Unfortunately there is no easy solution to this problem. There are third-party products offered for paint touch-up on the Titanium series, but we have not had good success with paint touch-up products. The design of this model PowerBook means that if you want to fix the paint chipping, you'll need to replace the upper case. It is not possible to replace only the lighter outer trim section as the two sections of the upper case are glued together.
If you lose firewire, USB, audio or ethernet, the only thing to blame is the logic board. Because there are many components of the logic board, numerous possible symptoms indicate logic board failure. Any one of these components can fail and leave the others intact. If you lose the use of another component of your computer, such as the display, battery, or even power, and replacing the apparently non-working part didn't fix the problem, it is possible that the [/Products/Titanium-Mercury/Logic-Boards/9/21|logic board] may need to be replaced.