EZ Battery Reconditioning Method
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The PMU (Power Management Unit) is a micro controller chip that controls all power functions for the computer. The PMU is a computer within a computer. It has memory, software, firmware, I/O, two crystals, and a CPU. Its function is to:
Important: The PMU is very sensitive and touching the circuitry on the logic board can cause the PMU to crash. If the PMU crashes, the battery life goes from about five years to about two days if the PMU is not reset. Refer to the next topic, "Resetting the PMU on the Logic Board" for the procedure.
Many system problems can be resolved by resetting the PMU chip. The PMU reset button is located behind the user access door, refer to the graphic below.
Location of the PMU Reset Button
Resetting the PMU (Power Management Unit) on the logic board can resolve many system problems. Whenever you have a unit that fails to power up, you should follow this procedure before replacing any modules.
4 Unplug all cables, except the power cord, from the computer.
5 Touch a metal surface inside the computer. Then unplug the power cord.This helps protect the computer from damage caused by electrostatic discharge. Important: To avoid electrostatic discharge, always ground yourself by touching metal before you touch any parts or install components inside the computer. To avoid generating static electricity, do not walk around the room until you have finished the procedure and closed the computer.
6 Press the PMU reset button (shown below) once and then proceed to step 7. Do NOT press the PMU reset button a second time because it could crash the PMU chip.
7 WAIT ten seconds before connecting the power cord and powering the computer on. If the computer powers on, go to the next step. If the computer does not power on, there is something else wrong with the computer, refer to the symptom/cure, "No Power" in this chapter.
8 Run MacTest Pro and return the computer to the customer.
Note: This entire procedure resets the computer's PRAM. Be sure to reset the computer's time, date and other system parameter settings before returning the computer to the customer.
There is a power-on self test that resides in the ROM of the eMac. This test automatically runs whenever the eMac is powered on after being fully shut down (the power-on self test does not run if the machine is only restarted).
If a problem is detected during the test, you will not hear a normal startup chime. Instead, the system will beep as explained below. Refer to "Error Beeps" later in this chapter for instructions on how to troubleshoot and repair an eMac that sounds error beeps at startup time.
Following is a definition of what the error beeps at startup time signify. One Beep: No RAM is installed or detected.
Two Beeps: Incompatible memory is installed. (The slots accept standard PC-100 or PC-133, 168-pin DIMMs).
Three Beeps: No RAM banks passed memory testing.
Four or Five Beeps: Bad checksum for the remainder of the boot ROM. The ROM is bad.
Logic Board Battery
Important: Apple highly recommends removing the battery when handling the logic board. Make sure to use proper ESD protection when handling modules.
The battery on the logic board controls the stored system settings, such as date and time. It is only necessary to test the battery when you can't power on the computer, or the date and time are reset every time the AC power is removed.
The battery is also used to power the PMU chip (because the PMU chip keeps time and must always be running) when the computer is unplugged from the wall (AC power). The PMU is very sensitive and touching any circuitry that is connected to the PMU can cause it to crash. If the PMU crashes, the battery life goes from about five years to about two days if the PMU is not reset. Once the battery goes dead, the PMU will reset the time and date every time the AC power is removed. To fix this situation, replace the battery and reset the PMU (refer to "Resetting the PMU on the Logic Board" mentioned earlier in this chapter).
If the computer has a "No Power" situation, check the battery before replacing modules. A drained battery may be indicative of a crashed Power Management Unit.
With the battery in the battery holder (under load), measure the voltage across the battery's positive and ground terminals.
With the battery in the battery holder (under load), measure the voltage across the battery's positive and ground terminals.
Does the battery measure at least +3.5v? If not, replace the battery and reset the PMU. If the battery does measure over +3.5v, reinstall the battery and reset the PMU as above
Connect the power cord and power up the system again.
Display/Analog Voltage Setting and LHR Module Instructions
The display/analog assembly contains a non-switching power supply which is preset at a 220V configuration.The voltage selection needs to be manually set by the way of a voltage jumper. This means if you are operating the computer in a 110V environment, you will have to install the voltage jumper.
The following instructions explain how to configure the voltage and LHR jumpers on the digital/analog assembly. Note: The LHR (a line conditioning module) is required in some international countries.
Refer to Table 1 for jumper settings and refer to Figures1, 2, and 3 for jumper and LHR locations. Tools
Voltage Environment |
Voltage Jumper Setting |
LHR Jumper Setting | ||||
110 V |
Jumper is on |
no LHR module |
Jumper is off |
with LHR module |
Jumper is off |
1. Locate the voltage jumper circled below in Figure 1. Note: this jumper won't be installed on a 220V computer. Next, refer to Table 1 (on the previous page) for the voltage jumper setting and set the jumper accordingly. Warning: Be careful around the CRT. Discharge the CRT before removing or replacing the jumper.
2. Locate the LHR coil jumper circled in Figure 2. Then refer to Table 1 for the LHR jumper setting and set the jumper accordingly.
3. Identify if you have the LHR coil (Figure 3) on the eMac. Note: The LHR coil (a line conditioning module) is required in some international countries.
Thermal Paste Application The microprocessor uses a heatsink/thermal pipe to transfer heat away. Whenever the heatsink is removed, the bottom side of the heatsink and the top of the microprocessor must be cleaned and thermal paste must be applied. If the mating surfaces are not cleaned and thermal paste is not applied, the CPU may overheat and become damaged. Tools This procedure requires the following tools:
Procedure 1. Thoroughly clean the thermal film from the heatsink surface with a plastic stylus or the nylon probe tool. Do not use an abrasive material or liquid cleaner. Important: Be extremely careful not to bend the heatpipes on the heatsink. ![]() 2. Carefully clean the surface of the microprocessor with a plastic stylus or nylon probe tool (922-5065) to remove the old thermal paste.
![]() CRT Neck/Display/Analog Assembly Handling Information Handling Important: It is imperative that proper handling and packaging guidelines be followed when working with the display/analog assembly. Do NOT lift, handle, bump, or manipulate the CRT neck/neck board (see red arrows below) on the Display/ Analog assembly. Modules damaged by mishandling are NOT covered by Apple Warranty. Apple Authorized Service Providers can be liable for broken CRT necks due to improper handling. Caution: The metal chassis has sharp edges, you may want to wear gloves when handling the assembly. Lift the assembly from the metal chassis; never lift the assembly from the neck. I Packing a Defective Display/Analog Assembly The packing procedure is included with the replacement display/analog assembly. Incorrect packaging can result in damaged eMac displays. Please read and follow the directions enclosed in the shipping box of the new display prior to packaging the defective assembly. AASPs can be liable for broken CRT necks due to improper packing and handling. ![]() Symptom Charts How to Use the Symptom ChartsThe Symptom Charts included in this chapter will help you diagnose specific symptoms related to the product. Because cures are listed on the charts in the order of most likely solution, try the cures in the order presented. Verify whether or not the product continues to exhibit the symptom. If the symptom persists, try the next cure. Note: If you have replaced a module, reinstall the original module before you proceed to the next cure. Apple Hardware TestApple Hardware Test is a diagnostic tool for detecting problems with Apple internal hardware components such as logic board, memory, modem, video RAM, and Apple AirPort Card. The test does not check externally connected hardware components such as USB or FireWire devices; it also does not check nonApple devices such as third-party PCI cards. Note: The most recent Apple Hardware Test software can be downloaded from the CD Images page on AppleCare Service Source; go to the Service Source home page and select 'Disc Images' from the quick-click table. Error CodesIf Apple Hardware Test detects a problem with a computer, it displays an error code, which is defined in the product's Error Code List. Consult the list for appropriate repair procedures associated with the code. All Error Code Lists are included in the Service Diagnostics Matrix, Knowledge Base article 112125. You can also access this matrix by clicking the Service Diagnostics rollover link under any of the product areas on the Service Source home page. ![]() No Power The computer will not power on.
7 Touch a metal surface inside the computer. 7 Touch a metal surface inside the computer. ![]() 8 Unplug the unit. 9 Verify the battery is good before replacing modules. A drained battery may be indicative of a crashed Power Management Unit. Does the battery measure at least +3.5v? If not, replace the battery and reset the PMU.
Warning: This product contains high voltage and a high-vacuum picture tube. To prevent serious injury:
![]() 15. Warning: Make sure the computer is unplugged. Check the fuse (see graphic below).You will need an ohm meter to do a continuity test on the fuse. Using an ohm meter, touch the red and black probes to the two metal points at location F901 and check for continuity (reading of "0"). If the ohm meter registers "0", the fuse is good. If the meter registers "infinite", the display/analog assembly should be replaced. ![]() 16. Plug the unit in. Check for AC voltage (see below). Warning: Do not force the probes into the connector. Doing so could break the connector. Do you measure 120V (line voltage)? If yes, go on to the next step. If no, replace the display/analog assembly. ![]() 17. Make sure the computer is plugged in. Check for 5V trickle on capacitor C3202 (located near the modem board) on the logic board (see graphic below). Do you get 5 V? If yes, go to the next step. If no, replace the display/analog assembly. ![]() 18. Check the down converter connector. Verify that it is properly connected. ![]() 19. Plug the unit in, but don't press the power button. Check the down converter. Be extremely careful when checking voltages. It is easy to short between the pins. Ground to the frame with the black probe and check pin 1 on P801 with the red probe. A reading of 10.5V up to 17.5V is acceptable. If you get a reading in that range, replace the display/analog assembly. If not, replace the logic board. ![]() Random Shut Down While using the computer it just shuts down for no reason. 1. Check the jumper settings, make sure they are set correctly. Refer to the "Digital/Analog Voltage Setting and LHR Module Instructions" mentioned earlier in this chapter. Note: There is one jumper for the voltage and one jumper for the LHR coil. Both jumpers should be installed when the computer is operating in the 110V environment. If the jumpers are set correctly, refer to "No Power".
No Video No video to the internal display, the fan is spinning, there is drive activity
4 Touch a metal surface inside the computer. 4 Touch a metal surface inside the computer. ![]()
Vertical Raster Shift The raster moves up to the point where the menu bar is no longer visible. Replace the IVAD cable (922-5806). Follow the procedure below. Tools This procedure requires the following tools:
Procedure
![]() 4. Note: The screws on IVAD assembly need to be removed to access one end of the IVAD cable. Remove the screw (circled below) and then remove the metal cable cover. ![]() 5. Remove the remaining two screws on the IVAD assembly. ![]() With the nylon probe tool or needlenose pliers, remove the glue from the connector. Note: If you find it difficult removing the glue use a heat gun to soften the glue a bit and then remove it. Disconnect the cable after removing the glue. ![]() 8. With the nylon probe tool or needlenose pliers, remove the glue from the cable connector. Note: If you find it difficult removing the glue use a heat gun to soften the glue a bit and then remove it. ![]() IVAD Cable Replacement Procedure
Mass Storage Flashing question mark appears on the screen
Alternating flashing question mark and a flashing Mac OS face on a folder.
Hard drive spins, but won't mount to the desktop
Hard drive does not spin.
System hangs during normal startup process
CD or DVD tray won't open
Optical drive won't accept a CD or DVD
CD or DVD disc constantly ejects at startup
Optical drive doesn't spin
CD or DVD won't mount to the desktop
Sound Out No sound from either internal or external speakers
No sound from the headphones
Sound In No sound is recorded
Error Beep(s) Computer beeps at startup.
Modem No modem dial tone
USB Printing Problems eMac cannot print to attached known-good printer.
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You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.