Error 4013 ????

[Lycos1337]

What is going to happen, when the NAND has been removed and the Ipad is connected to 3utools?

If the NAND should be corrupted, i guess the ipad cannot be reanimated without a reprogramming of the NAND by a professional NAND-Programmer (which then will be equal to use the Ipad for spares only)

[TBC01]

OK..

I am making assumptions about diagnostics already performed.

1. microscopic inspection
2. power signature (monitoring of current draw in dfu and recovery state)
3. A check for shorted lines on pmic buck outputs
4. check pmic temperature for heat spikes when trying to enable recovery mode, it is only at this point the board will switch from usb to battery. if battery flat or duff fail (2) pretty much takes care of that problem.
5. always check for an open diode on twin backlight circuits, if this occurs the crappy system used kicks the poo out of the pmic forcing thermal shutdowns. a big problem on a1474 and a1475
6. routinely check diode D8100 at any sign of power problems in ipad 2-5, easy to run off blaming pmic here.

now for nand problems;

as a nand degrades addresses become unavailable in blocks, if memory serves 128k in size. cell failures often occur in clusters so block removal seems reasonable. If crutical data is corrupted you may find yourself needing itunes recovery.
If the nand has failed more seriously it may become inaccessible even to a ramdisk loaded temporary o/s such as that used to manage system recovery. Although other board failures can mimick this even incorrectly or errors in programming, the latter implies of course you have done some nand work on the device.

I believe I mentioned itunes/idevice programming/restoring phases earlier in this thread, more importantly what actual state a board should be and when.

first the board must be able to actually run, kick to recovery, load the temp o/s and reboot from that loaded ramdisk. Now itunes can talk and get replies from the device, the most popular response is "I cant talk to the nand so i cant fix it, ERROR40"

By then of course we know the board is actually working, cpu, tristar, ram, pmic all ok This accomplishes a number of hardware function tests, bilaterally if a flaky nand is causing the error 9, 4013, 4014 etc it will be replaced by error 40. error 40 is among the final reported errors prior to successful restores.
nand row 8 has numerous ppv1.8 feeds to nand, bad contacts or missing rails here will give "invalid die count" problems..

I operate all ipad diagnostics as described above, the entire process takes about 25mins. Why bother with 3utools? - it shows device state at any given times, its device timers are too shortly normally to actually flash after nand repairs but is useful for diagnostic tests. That may well be my very slow and very old pc takes forever to install on the fly device drivers....

Hopefully you or others may find my comments here useful and I would like to end this post with the following;

" If you don't know what something is supposed to be doing and when; how are you ever going to make it work properly? "
My fathers words to me when trying to build a home made Nascom 1 8bit computer 40years ago, he was a lecturer in electronic engineering. While somewhat agravating he did have a point lol

[abuuqudama]

Don't worry change u2 ic for error 4014
Do not change nand flash!

[abuuqudama]

Sorry iphone 5s-6 .....error 4013 change u2 ic is working
Do not charge nand flash

[Harrison986]

Same problem hardware problem sure

[parthiban.stml]

after long time not used my ipad 7 th generation when i'm charging now showing the itunes restore symbol, so i'm trying to restore by itunes but it is restarts by itself,could not start and failed with error 4013.

[Suredolik]

the Same Error happened