Apple iMac Intel 21.5 How to replace the HDD - Hard Drive Replacement

Before beginning, unplug your iMac and lay it on a soft surface as shown.
Stick a suction cup near each of the two top corners of the glass panel.
To attach the suction cups we sell, first position the suction cup with the movable handle parallel to the face of the glass panel. While lightly holding the suction cup against the glass, raise the movable handle until it is parallel with the other handle.
If your suction cups refuse to stick, try cleaning both the glass panel and the suction cup with a  mild solvent.
Gently lift the glass panel perpendicular to the face of the LCD enough to clear the steel mounting pins attached along the underside of the top edge of the glass panel.
Pull the glass panel away from the lower edge of the iMac and carefully set it aside.
During reinstallation, be sure to meticulously clean the inside of the glass panel and the face of the LCD as any dust or fingerprints trapped inside will be annoyingly visible when the machine is turned on.
Remove the eight 8 mm T10 Torx screws securing the display to the outer case.
The last two pictures are detail shots of each side of the display.
Slightly lift the top edge of the display out of the outer case.
Do not lift it too much. There are several cables attaching the display to the logic board.
Pull the vertical sync cable connector out of its socket on the LED driver board near the top left corner of your iMac.
Rotate the display out of the outer case enough to disconnect the LED backlight power cable from the LED driver board.
Disconnect the LED backlight power cable by depressing the locking mechanism while pulling the connector away from its socket (toward the bottom edge of the iMac).
The display data cable plug has a wire lock. Disengage the plug's lock by rotating the plastic tab so that it points upward. (It is not a pull tab.)
Pull the display data cable straight out of its socket on the logic board.
Do not lift up on the display data cable, as its socket is very fragile. Pull the cable parallel to the face of the logic board
Disconnect the LCD thermal sensor cable connector from its socket on the logic board.
If your fan is spinning full speed after completion, check this connection or the hard drive's thermal sensor cable.
Carefully pull the display toward the top edge of your iMac and lift it out of the outer case, minding any cables that may get caught.
Pull the hard drive temperature sensor connector toward the top edge of the iMac to disconnect it from its socket on the logic board.
Remove the two 9 mm T10 Torx screws securing the upper hard drive bracket to the outer case.
Slightly rotate the hard drive out of the outer case and lift it up off its  mounting pins toward the top edge of the iMac.
Be careful not to contact the AirPort card as you lift the hard drive out of its recess.
Disconnect the SATA data cable and SATA power connector from their respective sockets by pulling each connector away from the hard drive.
Before disconnecting the thermal sensor cable, take note of its orientation. It is extremely important to reinstall the connector in the current orientation so the fans will not run at full speed.
If you have multiple pins on your replacement hard drive, put the connector closest to the SATA connections and closest to the PCB board.
Disconnect the hard drive thermal sensor cable from the hard drive.
Remove the two T8 Torx screws securing the upper bracket to the hard drive.
Remove the upper bracket from the hard drive.
Remove the two T8 Torx pins from the other side of the hard drive.
Carefully peel off the piece of EMI foam attached to the front of the hard drive.
Don't forget to transfer this to your new hard drive.

The iPhone 7 speaker ships with a leash stick-on Wi-Fi diversity antenna that connects to the logic board.

Waterproofing alert. The speaker's output duct fits over a rubber speaker grille gasket for an added layer of ingress protection.
This design is nigh identical to the one we unearthed in the iPhone 7 Plus a couple hours ago.
The duct also has a fine mesh in case the speaker grille doesn't do its water-blocking job.

The SIM eject tool ,pushes on a plastic pin, that pushes a metal pin, which in turn, ejects the SIM tray.

Apple added a rubber gasket around the SIM tray.

You can Now remove the logic board to take a closer look at some silicon.

If you look closely, you'll see minor differences in connector sizes and locations, post holes, and screw locations between the logic board of iphone 7 and 7 plus.
Logic board one side contains 

1.Apple A10 Fusion APL1W24 SoC + Samsung 2 GB LPDDR4 RAM (as denoted by the markings K3RG1G10CM-YGCH)
2.Qualcomm MDM9645M LTE Cat. 12 Modem

3.Skyworks 78100-20  Avago AFEM-8065 Power Amplifier Module Avago AFEM-8055 Power Amplifier Module

And on the flip side contains:

1.SK Hynix H23QEG8VG2ACS 32 GB Flash
2. Murata 339S00199 Wi Fi/Bluetooth Module
3. NXP 67V04 NFC ControllerDialog 338S00225 Power Management IC
4. Qualcomm PMD9645 Power Management IC
5. Qualcomm WTR4905 Multimode LTE Transceiver
6. Qualcomm WTR3925 RF Transceiver

Even more chips on logic board:

1. Bosch Sensortec BMP280
2. Barometric Pressure Sensor
3. Apple/Cirrus Logic 338S00105 Audio Codec
4. Cirrus Logic 338S00220 Audio  Amplifier(x2)
5. Lattice Semiconductor ICE5LP4K

6. Skyworks 13702-20 Diversity Receive Module
7. Skyworks 13703-21 Diversity Receive Module
8. Skyworks 77363-1

Remaining ICs On logic board

1. Avago LFI626 200157
2. NXP 610A38
3. TDK EPCOS D5315
4. Texas Instruments 62W8C7P
4. Texas Instruments 65730A0P Power Management IC
After logic board is out, its free to pick out the Lightning connector assembly.

Prying up the light adhesive went well, but our first tug was in vain. There are some extra screws in this port.
It seems like Apple has taken our warning to heart. Without a headphone jack to bear the burden of audio connections, this port will get a lot more wear, and it's been well reinforced.
Other denizens of the Lightning cable an antenna, two  microphones, two speaker grille plugs, and the Lightning port.

Scraping the bottom of the barrel phone case,  snag an antenna flex cable.

Also, a spidery mess of button cables. They're thin and fragile and tricky to remove intact, but they also snuggle up to a lot of waterproofed components. 

With the rear case nearly stripped, turn attention to the volume buttons that gave some trouble in the 7 Plus.

Persistent tugging with some tweezers rewards with a broken retaining flap, but this button cover still won't come quietly.
Next out is this weird c-clip looking thing.
And the button finally comes off, With two tiny gaskets, Apple is serious about this waterproofing.
This three-part mechanism is much more difficult to disassemble than the button covers, but hopefully the seal it provides means this removal procedure will be needed less frequently.

After some peeling, free the earpiece speaker and an all-new 7 MP FaceTime HD camera with deep trench isolation and auto image stabilization.

This is quite the upgrade from the 5MP FaceTime camera in the 6s.
The earpiece speaker is no slouch either, having been upgraded to serve as a second loudspeaker for legit stereo sound.
Also pluck out the solid state mini touch sensor, home "button."

Apple iPhone 7 - Specification - Disassembling procedure

Specification
1. Apple A10 Fusion processor with embedded M10 motion coprocessor
2. 32, 128, or 256 GB onboard storage capacity
3. 4.7-inch IPS multitouch Retina HD display with 1334 × 750 pixels (326 ppi)
4. 12 MP camera with f/1.8 aperture, optical image stabilization, and 5x digital zoom
5. 7 MP FaceTime HD camera with f/2.2 aperture and 1080p HD recording capability
6. Non-mechanical Touch ID home button driven by new Taptic Engine
7. 802.11a/b/g/n/ac Wi Fi + MIMO Bluetooth 4.2 + NFC
As you oppen iPhone 7,a few new additions on the surface:
A 1334-by-750, LED-backlit IPS display with a P3 color gamut and 25% higher brightness than that of the 6s.
An f/1.8, 12 MP camera with built-in optical image stabilization. Apple claims it's 60% faster and 30% more efficient than the previous generation.
A quad-LED True Tone flash that's 50% brighter than the iPhone 6s.

The iPhone 7 shares exact dimensions (138.3 mm × 67.1 mm × 7.1 mm) with its predecessor, the iPhone 6s-but has dropped a little weight, coming in at 138 grams compared to the 143 grams of the iPhone 6s.
DISASSEMBLING PROCEDURE
Power off your iPhone before beginning disassembly.
Remove the two 3.6 mm Pentalobe screws next to the Lightning connector.
If the plastic depth gauge is attached at the center of the Sclack, remove it now -it's not needed for larger phones like the iPhone 7.
Close the handle on the Sclack, opening the suction cup jaws.
Place the bottom of your iPhone in between the suction cups.
Position the Sclack's upper suction cup against the display, near the home button.
Open the handles to close the jaws of the Sclack. Center the suction cups and press them firmly onto the top and bottom of the iPhone
After briefly fighting through some sticky adhesives to open the case, you faced with another set of repair obstacles teeny tiny tri-point screws securing the cable bracket etc
With the front panel and strings of sticky glue out of the way, you can whip out our trusty spudger and disconnect the battery. Next, it's time to set our spudger to the task of popping off display connectors.
The iPhone 7 camera boasts a larger f/1.8 aperture, new 6-element lens and 12 MP sensor, four LEDs, and a flicker sensor that can sense flickering light and compensate for it in your photos and videos.
With the new camera out of the way, You can work our way deeper into the 7.
Next out: the audio baffle that thinks it's a headphone jack.
According to Apple, this plastic component is a barometric vent. With the added ingress protection afforded by the watertight seal, the iPhone uses this baffle to equalize the internal and atmospheric pressures in order to have an accurate altimeter.
This Taptic Engine takes advantage of its extra legroom, sizing up for its home button haptic duties.
With the path cleared, you can  use handy spudger to release the adhesive from beneath the battery.Wind up and peel out the three battery pull tabs.
The iPhone 7's power source.
Actually, it's a relatively benign Lithium-ion battery. This 3.8 V, 1960 mAh battery is rated for a capacity of 7.45 Wh.
Apple claims that this upgraded cell will provide up to 14 hours of 3G talk time, 14 hours of Wi-Fi internet browsing, and 10 days of standby.

Apple Mac mini – Disassembling – How to replace the RAM

RAM REPLACEMENT PROCEDURE 
You'll need a putty knife in order to open the case. A 1.5 inch thin putty knife will work well, but you'll want to grind the edge down. Rub the putty knife's short edge back and forth on a sheet of all purpose rough grit sandpaper (100 grit will work fine) until it attains a beveled edge.
Carefully insert a putty knife into the crevice in between the top cover and bottom housing. Start on the left side first. Push the blade down until you meet firm resistance (roughly 3/8 of an inch).
Gently enlarge the existing crevice by prying the handle of the putty knife downward and away from the mini.
It helps to start in the middle, then work along the edge until the bottom housing pops up slightly.
Next insert the putty knife into the crevice on the optical drive slot side of the computer.
Pry the putty knife downward while working along the edge of the mini until the bottom housing further separates from the top housing.
Repeat the same procedure as the past few steps for the right side of the mini.
At this point, there should be a noticeable gap between the bottom and top housing around the perimeter of the mini. Turn the mini over.
Gently lift the top housing straight up off the mini and set it aside. It may be necessary to wiggle the top housing while lifting it off the bottom housing. If any of the tabs get stuck on the top housing, use the putty knife to free them.
Later in this guide you will remove several recessed Phillips screws. Bit drivers are generally too large to fit in the recesses, so be sure to have a thin shafted Phillips screwdriver on hand.
First remove the AirPort antenna (the larger of the two), located near the power button.
Slightly squeeze the two retaining arms toward each other and lift the AirPort antenna off its post.
Squeezing the two posts excessively will surely break them off the internal frame. Work delicately.
During reinstallation, you will have to slightly squeeze the two posts together so they fit into the openings on the AirPort antenna board.
Use the tip of a spudger to slightly lift the left side of the ZIF cable lock up from its socket.
The ZIF cable lock will lift about 1 mm and stop. Do not try to completely remove the ZIF cable lock.
Lift the audio board ribbon cable up out of its socket.
If it refuses to lift from its socket, the ZIF cable lock is not fully released. Make sure it is evenly lifted about 1 mm from the socket on the interconnect board.
Rotate the mini so that the SuperDrive slot loading mechanism is facing you. Use a pair of tweezers to lift the hard drive thermal sensor cable connector up off its socket on the logic board.
Use tweezers to grab the connector (as seen in the picture), not the wires. The connector is located under the optical drive opening, next to the PRAM battery.
In the next few steps, you will remove the four Phillips screws securing the internal frame to the bottom case. Included in each step is an overview picture showing the general location and a closeup showing the actual screw.
Remove the recessed Phillips screw near the power button securing the internal frame to the bottom housing.
Remove the recessed Phillips screw near the sleep light securing the internal frame to the bottom housing.
This screw is the longest of the four screws securing the internal frame to the bottom case.
Remove the Phillips screw from the internal frame near the Bluetooth antenna.
Remove the Phillips screw near the audio ports securing the internal frame to the bottom case.
Gently lift the internal frame up from the bottom housing, minding the AirPort antenna and any other cables that may get caught.
It may be necessary to pull up near the interconnect board to separate it from the logic board.
Simultaneously pull the tabs on each side of the RAM chip away from the center of the chip.
These tabs lock the chip in place and releasing them will cause the chip to "pop" up.
Pull the RAM chip directly out from its connector.
If there are two RAM chips installed, repeat the above procedure for the second chip.