Target Search Keywords: iMac Pro A1862 power supply replacement, ADP-500AF PSU, 661-08944 power board, iMac Pro no power repair, iMac Pro A1862 teardown, iMacPro1,1 power supply swap, 500W iMac Pro power supply
Compatibility Information
Compatible Device: 27-inch iMac Pro, Model A1862
Model Identifier: iMacPro1,1
EMC Number: EMC 3144
Release Year: Late 2017
Official Part Codes
Apple Part #:
661-08944
Manufacturer Part #:
ADP-500AF / APG009 / APG003
Power Rating:
500W
Input: 100–240V AC, 50/60Hz Worldwide Universal Voltage
✅ Fits all Late 2017 A1862 iMac Pro factory configurations:
- 8-Core Intel Xeon W-2140B
- 10-Core Intel Xeon W-2145
- 14-Core Intel Xeon W-2150B
- 18-Core Intel Xeon W-2155
GPU Options: Radeon Pro Vega 56, Radeon Pro Vega 64, Radeon Pro Vega 64X
Storage: All original Apple SSD modules for A1862
This 500W PSU is the original factory power board for every A1862 iMac Pro, works regardless of CPU / GPU / RAM variant.
❌
NOT Compatible With:
Regular 27” iMac A1419, A2115, M1 / M3 24" iMac, Mac Pro Tower, A1418, A2438 or any other Apple desktop models. This power supply will not fit any iMac other than A1862 Late 2017.
Item Condition
Used OEM Pulled Power Supply Board, removed from fully working original iMac Pro A1862.
Fully tested: No short circuit, stable voltage output, no bulging capacitors, all connectors intact. Tested working before shipment.
iMac Pro A1862 Power Supply Replacement Tutorial
(Step-by-Step PSU Swap Guide | How to fix iMac Pro no power issue)
High search intent keywords: how to replace iMac Pro A1862 power supply, iMac Pro no power troubleshooting, iMac Pro teardown guide for repair
⚠️ EXTREMELY IMPORTANT SAFETY WARNING
- Unplug the AC power cord completely. Wait a minimum of 10 minutes for high-voltage capacitors inside the PSU to fully discharge. High voltage can cause serious electric shock!
- Use an anti-static wrist strap and anti-static work mat. Static discharge can damage the power supply, logic board and other sensitive components.
- Recommended repair tools: Suction cups, plastic pry picks, Torx T3, T4, T5, T8 screwdrivers, tweezers.
- Back up all user data before disassembly. This repair requires removing the front glass and LCD panel; it is an advanced-level Apple desktop repair. If you have no iMac repair experience, please send your machine to a professional Apple repair shop.
- Take clear photos of every cable connector before unplugging for reference during reassembly.
Step 1: Remove front glass and LCD assembly
Attach suction cups to the front glass panel. Lift the glass slowly and disconnect the camera and microphone ribbon cables. Set the glass aside safely.
Remove all Torx screws holding the LCD screen. Disconnect the LCD eDP display cable and backlight cable, then carefully lift out the LCD panel. Keep the LCD away from sharp metal edges to avoid screen cracking.
Step 2: Disconnect cables to access the power supply
Disconnect the main power harness from the logic board, fan cables, temperature sensor cables and any auxiliary power connectors routed near the PSU.
Step 3: Uninstall the old faulty power supply
Locate the 500W power supply board mounted at the rear chassis. Unscrew all Torx mounting screws securing the PSU. Unplug the AC input cable and all output power connectors. Slide the old power supply out gently.
Step 4: Install the replacement pulled ADP-500AF power supply
Align the new PSU into the original chassis position. Secure all mounting screws back in place; do not over-tighten screws to avoid PCB cracking.
Reconnect the AC input cable and all power output connectors. Double-check every plug is fully seated and locked.
Step 5: Reconnect internal cables, fans and sensors
Reattach all fan connectors and temperature sensor cables correctly. Poor sensor connection will trigger constant high fan speed, overheating or boot failure.
Step 6: Reinstall LCD screen and front glass
Reconnect the LCD backlight cable and eDP display cable. Mount the LCD panel and fasten all LCD screws. Reconnect camera and microphone ribbons, then re-seat the front glass panel. Clean adhesive surface to prevent dust trapped behind the screen.
Step 7: Power on and full function testing
Plug in the AC power cord and power on the iMac Pro.
Test boot up sequence, video output, Thunderbolt 3 ports, USB, Ethernet, Wi-Fi, Bluetooth, audio, fan speed regulation and GPU function.
✅ If the machine boots normally and all features work, your power supply replacement is complete.
Common Troubleshooting Tips
- No power after replacement: Check AC input connector, confirm capacitors fully discharged during installation
- Fan running at full blast: Recheck temperature sensor connectors
- Random shutdown: Inspect all power output connectors for loose or bent pins
FAQ Section (High Volume Search Questions)
Q: Does this PSU support all Xeon W and Vega GPU versions of A1862?
A: Yes, this is the stock 500W power supply for every factory A1862 configuration.
Q: Do I need to reprogram SMC after swapping the power supply?
A: Normally no programming required for original pulled tested PSU. If you get power but boot issues, reset the SMC on your iMac Pro.
Q: Can I use this power supply on a 2019 or 2020 iMac Pro?
A: There is no 2019 / 2020 release of iMac Pro. The only iMac Pro model is Late 2017 A1862.
