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LTE-enabled variant of the fifth generation of iPad, released in March 2017. Available with 32 and 128 GB storage options featuring a 9.7" Retina display and 64-bit A9 processor.

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iPad 5 charges when powered off; testing data included

I have two iPad 5th generation tablets (data/GPS), one 10 W OEM charger and one 12 W OEM charger with many OEM lightning cables.


One of the iPads charges very slowly and only in a certain connection. I bought it used with this problem. It otherwise functions normally with normal battery life and battery % display is normal. I have not opened it but there is no obvious sign of damage. The charge port was cleaned by me but not much was pulled out. The contacts were lightly cleaned with IPA, no obvious sign of damage to the contacts is seen either. I haven't had any trouble syncing/backing up with iTunes. A DFU restore was also performed but made no difference.


Using a USB ammeter which also gives the state of the data lines, the following info was gathered. The ipad is approximately 55% charged during these tests. Similar results are found with the 10 W charger and combinations of charger/cable. The other tablet charges just fine with these accessories.


12 W charger; no device plugged in

A: 0A

V-: 0V

D-: 2.77V

D+: 2.76V

V+: 5.18V

Ohms: 999.9

Watts: 0W


12 W charger; faulty iPad powered on, same result if in sleep or wake state

A: 0A

V-: 0V

D-: 2.74V

D+: 0.07V

V+: 5.18V

Ohms: 999.9

Watts: 0W

note: Upon plugging in, the iPad briefly wakes up and displays "Unlock iPad to use accessories"; no charging icon is seen.

note2: sometimes the result of this test was:

A: 0.06A

V-: 0V

D-: 2.74V

D+: 0.09V

V+: 5.18V

Ohms: 86.33

Watts: 0.31W

with no "unlock" notification but still no charging icon


12 W charger; faulty iPad powered off after plugging in to charge (if I plugged the tablet in when it was powered off, it would power on)

A: 0.47A

V-: 0V

D-: 2.65V

D+: 0.21V

V+: 5.17V

Ohms: 11

Watts: 2.42W


MacBook Pro; no device plugged in

A: 0A

V-: 0V

D-: 0V

D+: 0V

V+: 5.03V

Ohms: 999

Watts: 0W


MacBook Pro; faulty iPad powered on but in sleep state

A: 0A

V-: 0V

D-: 0V

D+: 0V

V+: 5.03V

Ohms: 999

Watts: 0W

note: Upon plugging in, the iPad briefly wakes up and displays "Unlock iPad to use accessories" notification pops up


MacBook Pro; faulty iPad powered on but in wake state (screen is unlocked)

A: 0.95A

V-: 0V

D-: 0.16V

D+: 0.17V

V+: 4.86V

Ohms: 5.11

Watts: 4.61W


MacBook Pro; faulty iPad powered off

A: 0.47A

V-: 0V

D-: 0V

D+: 0.14V

V+: 4.95V

Ohms: 10.53

Watts: 2.32W


The results on the MacBook were similar for both iPads.


With the charger, the normal iPad charges like this:


12 W charger; normal iPad powered on but in sleep state

A: 2.00A

V-: 0V

D-: 2.65V

D+: 2.65V

V+: 5.13V

Ohms: 2.6

Watts: 10.1W

note: no notification pops up


12 W charger; normal iPad powered off after plugging in to charge

A: 1.89A

V-: 0V

D-: 2.65V

D+: 2.65V

V+: 5.13V

Ohms: 2.7

Watts: 9.7


It seems there may be a problem on the D+ line. It drops to low voltage when a charger is plugged into the faulty iPad. I think this then makes the iPad think it shouldn't draw much power. The best way to charge (0.5 A) is from a charger when powered off.


If this is definitely a tristar/tigris problem, I probably won't attack it myself but if you think this could be a connector problem then I may try to fix it myself.


Thanks for any help.

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I just did these tests again and realized that the D- line is the one that drops. I don't know if these are different results or if I made a bad record keeping mistake. Regardless, I'm sad no one has any input.

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I am always very happy to help people if I can, but I personally feel a bit sick when I see endless lists of voltage measurements and i usually just pass by. I have no idea how the other techs on this forum feel about that, but fact you didn’t get any answer gives me a hint.

However, getting to your problem..if I had an issue such as yours, I’d rule out a charging port fault and head straight for Tristar replacement which is coherent with the “charging when turned off” behavior and with use of “OEM” cables. BTW, there are no OEM cables in the market, closest you can get is third party MFI certified but one always needs to check Apple’s database as big marketplaces are full of sellers claiming MFI compliance they don’t have in reality. Hope that helps.

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Thank you for your time and help.

When beginning to compose a message, the page advised to give as much detail as possible. I suppose it was overkill in this post. I have collected 4 OEM lightning cables over the years. They're the only ones I use.

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Had this before. If a USB ammeter is reporting 0.00 while iPad is on and you have tried multiple cables and chargers plus the charging port is in good condition it is 100% charging IC.

The one I did today in particular reported fake charging on some cables and some didn't detect at all from iPad

For your case I would suspect charging port on its way out. Usually one or two pins are pushed down under microscope indicating it is worn out.

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I’ve dealt with numerous iPads doing the same behavior.

Unfortunately, there is no one solution for all. It really could be charging port, Tristar, battery, PMIC, or any combination of the above. I even had one that I could not solve despite replacing all the above, unless the PMIC I used was defective because it was warming up and I had no other spare parts. Those PMIC are pretty expensive by the way and replacing them requires a fair amount of skill.

The PMIC integrates charging in iPads, by the way. So if “Tigris” is misbehaving, it is actually the PMIC.

It used to be very seldom the PMIC. Now I am starting to see more and more of them. I guess they are starting to die more frequently after all this time in operation.

I think the numbers you listed could point to that. But you need to rule out everything else first.

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