Q: iphone wont charge when connected to computer. It wont show the charging icon

Holding down on the power button will bring up the slide to power off screen. You should not see anything other than the slide to power off bar and the cancel button, you will not see a need to charge icon, whatever that is. I never heard of the need to charge icon.

Does the phone charge when you use the supplied adapter and plug it into a wall socket? That is how the device is meant to charge.

If your iPhone, iPad, or iPod touch won't charge - Apple Support

Demo wrote:

 

Holding down on the power button will bring up the slide to power off screen. You should not see anything other than the slide to power off bar and the cancel button, you will not see a need to charge icon, whatever that is. I never heard of the need to charge icon.

 

Does the phone charge when you use the supplied adapter and plug it into a wall socket? That is how the device is meant to charge.

If your iPhone, iPad, or iPod touch won't charge - Apple Support

I'm guessing the "need to charge icon" is the empty battery that comes up when you try to power on a dead iPhone. If that's the case, plugging it in to a computer will likely take a fairly long time to provide enough power for the phone to power on and continue to charging.

Use the OEM adapter and cable that came with the phone for best charging results.

Try cleaning out the charge port. Often lint and dirt gets compressed in there. You need something small enough to get in there to scrape out the stuff. Have a look inside first with a torch so you can see the contacts, which you want to avoid damaging.

Get something like a Jeweler's Loupe and a good flashlight. Check the charging port very carefully to see if there's anything in there that could be interfering with the cable making connection to charge the battery. Also, check the cable to ensure that it's good with another device, and maybe check the port on the computer that you're using to ensure it is working properly as well.