iMac (Late 2012) Introduction This course provides technicians with important information and service highlights preparing them to: Successfully pass the iMac (Late 2012) Qualification Exam Service and repair the iMac (21.5-inch, Late 2012) and iMac (27-inch, Late 2012) Lesson Overview Lesson Objectives Upon completion of this course you should be able to: Explain the features of the iMac (21.5-inch, Late 2012) and iMac (27-inch, Late 2012). Exercise technician safety precautions.
Only qualified technicians may perform repairs on the iMac (21.5-inch, Late 2012) and iMac (27-inch, Late 2012). Technician Qualification Process 1. Complete this course. 2. Take the iMac (Late 2012) service qualification exam. Note: You must score 90% or higher in the Technician Safety section of the exam to pass. If you score lower than 90% in this section, you will fail the whole exam regardless of your performance in other sections.
Logic Board: 21.5-inch Logic Board: 27-inch Electrical Safety Precautions Before working on a computer with exposed, potentially energized parts: 1. Remove rings, watches, necklaces, metal-rimmed eyewear, and other metallic articles which increase your risk of electric shock. 2. Do not wear a cell phone or other signaling device, as these may cause a dangerous startle reflex during energized work. 3.
iMac (21.5-inch, Late 2012) iMac (27-inch, Late 2012) iMac (21.5-inch, Late 2012) iMac (27-inch, Late 2012) iMac (21.5-inch, Late 2012) iMac (27-inch, Late 2012) Side View Rear View The iMac (Late 2012) models are most easily distinguished by its distinctive shape and SDXC card slot on the rear housing.
iMac (21.5-inch, Late 2012) Display 21.5-inch (diagonal) LED-backlit display with IPS technology; 1920-by-1080 resolution with support for millions of colors Processor 2.7GHz quad-core Intel Core i5 processor (Turbo Boost up to 3.2GHz) with 6MB L3 cache 2.9GHz quad-core Intel Core i5 processor (Turbo Boost up to 3.6GHz) with 6MB L3 cache 3.1GHz quad-core Intel Core i7 (Turbo Boost up to 3.
A: Headphone B: SDXC card slot C: USB 3 ports D: Thunderbolt E: Gigabit Ethernet Exploded Views iMac (21.
Service Tools The following tools are required to service an iMac (Late 2012): ESD-safe workstation, including an ESD mat and wrist or heel strap ESD bags (to store ESD-sensitive parts while removed from computer) Kit, Starter, LCD Display Panel, 076-1416 Kit, LCD, Service Refill, iMac (21.
076-1419 Kit, LCD, Service Refill, iMac (27-inch, Late 2012) Very High Bond, VHB, 6-piece set, 20-pack, 076-1419, iMac (27-inch) (qty 20) Display removal wheel (qty 20) Handle, display removal tool, iMac (qty 1) Additional Tools and Supplies Needed to remove, handle and clean the display panel: 922-9468 – ESD bags, 24”x30”, Pkg of 5. To prevent buildup of static charges which may attract dust particles, store the display panel in an ESD bag when removed from the unit.
Take Apart Tips Review the Electric Shock and Glass Safety precautions found in the beginning of this course. Follow all cleaning and handling instructions to prevent damaging display panel or LCD panel. Never place display panel onto a work surface where it may collect dust and other contaminants. Always place it into a protective microfoam bag. The chin strap must be removed for the majority of repairs.
display panel's surface. iMac (Late 2012) Glass Display Panel Removal Important: Review the entire video. Concepts presented will be covered in the iMac (Late 2012) qualification exam. Display Removal Tool As presented in the video, the display removal tool cuts the foam core sandwiched between two layers of the Very High Bond, or VHB adhesive.
Important: Review the entire video. Concepts presented will be covered in the iMac (Late 2012) qualification exam. Broken Displays Tools and Equipment Checklist Display panel starter kit, 076-1416 Leather gloves or equivalent cut-resistant gloves Packing tape or equivalent Safety glasses Large ESD bags, 922-8258 Large box for disposal Removing a Broken Glass Display Panel 1. Put on safety glasses and leather gloves. 2.
5. Place taped display panel in the ESD bag that the replacement panel came in (or equivalent large bag). 6. Place the display panel inside a large box, label the box "Broken Glass".
7. Send the display back to Apple. VHB Strip Identification Very High Bond (VHB) Strip Identification Printed on each Very High Bond (VHB) strip is an ID number (on the pull tab) and part number. Prior to installation, lay the strips out according to the appropriate diagram. Part numbers printed on the individual VHB strips (949-xxxx) are for visual identification only, and cannot be individually ordered. VHB strips are only available as part of a starter or refill kit.
VHB Strip Description Top left VHB Strip ID Number 01 Part Number on VHB Strip 946-4469 Top right Right side Bottom Left side 02 03 04 05 946-4471 946-4472 946-4468 946-4470 VHB Strips: iMac (27-inch, Late 2012) VHB Strip Description VHB Strip ID Number Part Number on VHB Strip Top left Top right Right side Bottom, right side 11 12 13 14 946-4547 946-4548 946-4549 946-4551 Bottom, left side Left side 15 16 946-4450 946-4552 Display Replacement Very High Bond (VHB) Adhesive Installation
Important: Review the entire video. Concepts presented will be covered in the iMac (Late 2012) qualification exam. iMac (Late 2012) Glass Display Panel Replacement Important: Review the entire video. Concepts presented will be covered in the iMac (Late 2012) qualification exam.
Important Only use side-to-side motion when wiping or polishing display panel. Do not use the sticky silicone roller to clean the display panel. Diagnostic LEDs Both the iMac (21.5-inch, Late 2012) and iMac (27-inch, Late 2012) have four built-in diagnostic light-emitting diodes (LEDs) and two test pads on the logic board that can help you to troubleshoot the computer. WARNING Be extremely careful when troubleshooting or working inside the computer when it is plugged into an electrical outlet.
Use a flat blade screwdriver to reset the real time clock (C). LED Indicators LED 1 Indicates that the trickle voltage from the power supply has been detected by main logic board. This LED will turn ON when you connect the iMac to a working AC power source. The LED will remain ON as long as the computer is ON or asleep.
3. Turn logic board over and remove the Wi-Fi/Bluetooth card by pulling the card straight out of its receptacle. 4. Using a black stick, gently remove thermal material off the logic board and wireless card. Wipe areas clean with IPA wipe. Wireless Card Installation 1. Locate burstable twinpak of thermal material - Part # 076-1425. Wear protective gloves. 2. Using a black stick, push thermal material from one side of twinpak sleeve to the other side of twinpak sleeve. 3.
4. Mix the contents of the twinpak back and forth, until the material is uniform in color. If you see striations or non-uniform color, continue mixing. 5. Before applying the material, cover the wireless card connectors with Kapton tape to prevent excess thermal material from contaminating the connectors. 6. Cut the corner of the twinpak sleeve.
7. Squeeze approximately a quarter of the packet or a .5 inch (12.7mm) strip onto the wireless card as shown. 8. Remove the Kapton tape covering the wireless connectors, align the Wi-Fi/Bluetooth and slide the card into its receptacle. 9. Install the two (2) Torx 4 923-0330 screws.
10. Reinstall logic board and reconnect Wi-Fi/Bluetooth cables using the routing below. The logo antenna is the first connector, then connect the antennas clockwise. About the thermal material A thermal material twinpak is included with every replacement wireless card and logic board. It can also be ordered separately (076-1425). The thermal material requires mixing before applying to the wireless card.
First Steps Remove display panel, fan, hard drive, hard drive cable, chin strap and right speaker. Loosen power supply. Memory Module Removal 1. Remove logic board and remove memory modules by pressing the side tabs outward. 2. Pull memory module out after it releases from the tabs. Memory Module Installation 1. Align memory module and insert. iMac (21.
Open RAM Access Door 1. Use a black stick to open the RAM access door lock mechanism. Press "in" on the lock mechanism until the RAM access door pops up. 2. With your fingers, remove the RAM access door. Memory Module Removal 1. Push memory levers outward to release memory cage.
2. Pull memory levers toward you (#1); pull memory out of slots (#2). Memory Module Installation 1. Align the notch on the memory with the notch on the slot.
If you have two DIMMs, insert into slots 2 and 4 (as shown below). The slot closest to rear housing vents is Slot 1. 2. Use the DIMM insertion instructions on the inside of DIMM door as a guide. 3. Press memory firmly into slot until you feel a click. 4. Push the levers back into the rear housing until they click into the memory compartment. 5. Reinstall RAM access door.
Chin Strap The chin strap must be removed for the majority of repairs. Chin strap screws are very small. There are 4 longer screws and 1 short. Install the short screw in the center hole. Remove screws in the following order: Replace screws in the following order: The screws are very small and challenging to re-install. Use a black stick to press the chin strap against the front frame if needed. DO NOT press on the chin. Always press on the back of the chin strap to bring it toward the screw.
Hard Drive Replacement If installing a replacement hard drive, transfer the hard drive brackets onto the new drive. The brackets install only one way. Be sure to orient them correctly. Left Bracket Right Bracket Be careful not to pinch the cables under the Hard Drive Cradle assembly. Wi-Fi/Bluetooth Antennas iMac (21.5-inch, Late 2012) has four (4) Wi-Fi/Bluetooth antennas. Three of which are removable. The fourth resides inside the Apple logo in the rear housing assembly.
Speaker Replacement Speakers must be replaced in pairs. If you replace the right speaker you must replace the left one also. If you replace the left speaker you must replace the right one also. Push firmly to ensure the speaker sits down in the chin as far as possible. If the speaker isn't far enough down in the chin, it can cause display interference issues. When replacing the left speaker, remove the power button cable from its routing. failure to do so can result in a damage power button cable.
Reinstall the seven (7) Torx 8 screws in the following order: Rear Housing Replacement
Rear housing includes the following parts: Wi-Fi antenna in silver circle behind Apple logo Microphone Power button and cable AC inlet Gaskets Important: Replacement of any of these parts require replacement of the entire rear housing. These components are not available as individual parts. Always handle rear housing with 2 hands in the lower left and right corners. Handling rear housing part incorrectly could flex aluminum and cause alignment issues.
Wi-Fi/Bluetooth Antennas iMac (27-inch, Late 2012) has four (4) Wi-Fi/Bluetooth antennas. Three of which are removable. The fourth resides inside the Apple logo in the rear housing assembly. It can only be replaced by replacing the rear housing. Speaker Replacement Speakers must be replaced in pairs. If you replace the right speaker you must replace the left one also. If you replace the left speaker you must replace the right one also.
When replacing the left speaker, remove the power button cable from its routing. failure to do so can result in a damage power button cable. A damaged power button cable requires a rear housing assembly replacement. Stand Replacement When replacing the stand, remove nine (9) Torx 8 screws.
Rear housing includes the following parts: Wi-Fi antenna in silver circle behind Apple logo Microphone Power button and cable AC inlet Gaskets Wireless antenna insulators Important: Replacement of any of these parts require replacement of the entire rear housing. These components are not available as individual parts. Always handle rear housing with two hands in the lower left and right corners. Never carry the rear housing with a single hand or push in or pull out on the chin.
not connected to an AC power source. The RTC maintains the system date and time, while the PRAM stores information such as speaker volume, screen resolution, startup disk selection, and recent kernel panics. The coin battery is designed to last several years and does not normally require replacement. However, if issues with the functions listed above are experienced, the RTC and PRAM may need to be reset, or the Coin Battery may need to be replaced.
Recovery HD A bootable OS X Utilities volume is installed on a hidden partition (Recovery HD) of the internal drive, and may be used to perform the following tasks: Repair the internal drive using Disk Utility Erase or Partition the internal drive using Disk Utility Restore information on the internal drive using a Time Machine Backup Restore or Reinstall OS X and Apple applications on the internal drive from the Internet To boot from Recovery HD: 1.
Mac OS X versions (builds) for computers Mac OS X: Starting up in Safe Mode Mac OS X: What is Safe Boot, Safe Mode? Monitor and display adapter table OS X: About OS X Recovery Recovering a lost firmware password Safe Boot takes longer than normal startup SERVICE: Latest Apple Service Toolkit download links and documentation Thunderbolt ports and displays: Frequently asked questions (FAQ) Using USB 3 devices on Mac computers FAQ
