iPhone 4 UMTS antenna repair guide

Your phone has a weak signal or no signal at all

In this guide, we show you how to replace your iPhone’s defective UMTS antenna. This repair can help if your iPhone can no longer find a signal, or only gets a weak one.

Required tools

For storing screws

For storing screws

We recommend storing your screws so you don’t mix up the various screws and small parts.
from €10.99 on Amazon
Menda ESD Spudger

Menda ESD Spudger

You need a flat plastic prying tool to disconnect the various plugs and connectors.
from €26.38 on Amazon
Tweezers

Tweezers

We recommend using tweezers to remove screws and various small parts from your device.
on Amazon
Steel Laboratory Spatula

Steel Laboratory Spatula

You need a flat and sturdy prying tool to disconnect glued parts.
on Amazon
Pentalobe PL1 screwdriver

Pentalobe PL1 screwdriver

You need the right screwdriver for removing pentalobe PL1 screws.
on Amazon
Phillips PH00 screwdriver

Phillips PH00 screwdriver

You need the right screwdriver for removing PH00 screws.
from €10.84 on Amazon

Required replacement part

iPhone 4 UMTS-Antenna

iPhone 4 UMTS-Antenna

from €14.90 on Amazon

Show all replacement parts for the iPhone 4

Steps

15 Steps

Removing the enclosure screws

Step 1

Removing the back cover

Step 2

Disconnecting the battery connector

Step 3

Removing the battery

Step 4

Plastic tab

Step 5

Disconnecting the dock connector cable

Step 6

Removing the speaker

Step 7

Preparing the new antenna

Step 8

Installing the speaker

Step 9

Attaching the dock connector cable

Step 10

Aligning the plastic tab

Step 11

Installing the battery

Step 12

Attaching the back cover

Step 13

Fastening the enclosure screws

Step 14

Setting the time

Step 15

Getting started with the repair of your iPhone 4

If you get stuck or have questions, you can post a comment. We’d be happy to help.

15 steps

Removing the enclosure screws
Depending on when your iPhone was manufactured, you’ll need either a Phillips screwdriver or a pentalobe screwdriver to open your phone.

Depending on when your iPhone was manufactured, you’ll need either a Phillips screwdriver or a pentalobe screwdriver to open your phone. They are located to the right and left of the dock connector. Put the screws in the same compartment of your organizer tray.
2 x 3.6 mm pentalobe/Phillips screws
Removing the back cover
Use your thumbs or the palm of your hand to push the back cover of your iPhone about 4 mm away from the bottom of the phone where the dock connector is (see figure 1).

Then you can lift the back cover at the end that’s sticking out past the phone (see figure 2).
Disconnecting the battery connector
If your iPhone’s still on, turn it off now by holding down the standby button for about five seconds and following the prompt on the display.

Remove the screw on the battery connector using a Phillips screwdriver (see figure 1). Put the screw in a separate compartment of your organizer tray.
1 x 2.6 mm Phillips screw
The battery contact point on the logic board could come off. If the contact point breaks off but the soldering points are still intact, you can solder the contact point back on.

Now carefully lift off the battery connector by inserting the pointed ESD spudger slightly below the silver cover plate (see figure 2). If you don’t have a spudger, you can also try using your fingernail.

For the rest of the repair, you can also use the metal laboratory spatula instead of the spudger. This may make some steps easier for you. However, we explicitly recommend using the ESD spudger produced specifically for precision electronics.
Removing the battery
The antenna cover is under the battery connector. NRemove the cover and put it in the same compartment of your organizer tray as the Phillips screw you removed before. (See figure 1).

Now remove the battery. It’s sometimes glued firmly in place. Insert the flat end of the spudger into the space (about 1 cm to the left of the volume down button) between the battery and the outer frame, and slowly lift the battery (see figure 2). If the battery’s really stuck on, use other leverage points to the right and left of the original spot to pry it off. If you still can’t detach the battery, you can use a heat gun to warm it slightly from the outside and soften the glue.

Now you can also disconnect the antenna connector by carefully pulling it off the plug head using the spudger (see figure 3).
Plastic tab
Fold the plastic tab with the warning over and press it firmly onto the lower adhesive strip. This way, it won’t get in the way during your repair.

Of course, you can also remove the plastic tab.
Disconnecting the dock connector cable
Remove the two Phillips screws from the dock connection cable and remove the black (silver for newer models) cover (see figure 1).
1 x 1.6 mm Phillips screw
1 x 1.2 mm Phillips screw

Put the screws and cover in the same compartment of your organizer tray. It’s easy to tell them apart.

Now you can carefully detach the connector by using the flat end of the spudger to lift the connector again. Alternatively, you can also use your fingernail again (see figure 2).

Pull the flat cable that’s lightly glued in place off of the logic board and bend it carefully over the frame (see figure 3).
Removing the speaker
Unscrew the remaining Phillips screw on the speaker (see figure 1) and use the spudger to remove it (see figure 2). Put the screw in a separate compartment of your organizer tray.
1 x 2.4 mm Phillips screw

Preparing the new antenna
You have to remove the old antenna that’s attached to the speaker. Unscrew the two equally sized Phillips screws (see figure 1).
2 x 1.6 mm Phillips screws

Now remove the antenna, which is glued on, using the laboratory spatula and then stick a new antenna on (see figure 2).

Then you have to fasten the two Phillips screws again.
Installing the speaker
At first, only tighten the Phillips screw on the speaker a little bit (see figure 1).
1 x 2.4 mm Phillips screw

The speaker’s clips have to be against the speaker behind the higher level of the middle cover (see figure 2). This is easiest if you only slightly screw in the speaker at first so it can still move around a little.

Once the clips are fitted properly, you can tighten the screw.
Attaching the dock connector cable
Connect the dock connection cable again and put the black/silver cover on it.

Fasten the two Phillips screws again.
1 x 1.2 mm Phillips screw
1 x 1.6 mm Phillips screw
Aligning the plastic tab
Detach the plastic tab with the warning or stick it back in if you took it out.
Installing the battery
First you have to attach the antenna connector again (see figure 1).

Now put the battery back in the iPhone.

Then install the antenna cover (see figure 2).

Now click the battery connector back into place and screw it in (see figure 3).
1 x 2.6 mm Phillips screw
Attaching the back cover
Put the back cover back on and carefully push it the last few millimeters toward the dock connector.
Fastening the enclosure screws
Now screw in the two screws at the bottom of the enclosure.
2 x 3.6 mm pentalobe/Phillips screws

Then all you have to do is push in the SIM card tray.
Setting the time
When the battery is removed from the device, the iPhone loses the time and sets itself to 1:00 a.m. on 1/1/1970. You could have trouble connecting to the cellular network if the time isn’t set.
After a repair, complete the following steps:

Synchronize your iPhone with iTunes or connect to a WLAN network and wait until the time is set.

Remove the SIM tray with the SIM card and reinsert it.

Activate airplane mode on the device and then deactivate airplane mode.