Ipad 3 no Itunes, no Image

[Allan]

Ipad 3 came in for backlight repair.

Upon inspecting, the LCD they sent had no image.
Tried my known good LCD, still no image.
Plugged into Amp Meter, drawing normal power, let it sit for a while. Came back, still no image, no itunes
Plugged in DCPS, shows booting up to .54 and kind of skips around there
Board is very minorly warm but all over, not in a single spot that I can tell
Tried known good charge port
DCPS fluctuates from 60-.30, looks like normal booting
still no connection to Itunes

[Jessa_the_Professa]

Sounds like a case for rule #1---you need to boot the iPad in a known good housing with a known good charged battery and known good dock connector.

[crea2k]

Wouldn't it rule all of that out just running off the dtps ?, as it should boot just fine running off the power supply with nothing other than the power switch flex and the screen plugged in.

[crea2k]

When I'm looking at this type of problem the first thing id do is just turn off the power, disconnect from battery and then just do a sweep for shorts on all of the large / medium sized caps on the board. It may be a minor line that's stopping it booting.
I admit it's odd that you arnt getting anything on iTunes too, have you tried putting it into dfu mode ?. If it will go into dfu mode you can at least rule the charge port out as being a problem.

[Jessa_the_Professa]

The DCPS only substitutes for a battery, nothing else. Let's assume that this problem is "bad dock" Then he won't be able to prompt to boot from DCPS using the dock he has (assuming that it is tough to boot from DCPS using power button), he won't be able to charge a battery which explains why this ipad seems dead, and he won't be able to detect iTunes--which means that he won't be able to "know" that the device has booted assuming it has a backlight issue by now from struggling to boot it off a bad dock, or assuming that it is auto-booting to recovery mode.

Essentially--there are a LOT of variables and possibilities there, a known good housing elminates a lot of them!

[Allan]

tried in a known good housing, with battery and dcps, behavior is the same.

[Jessa_the_Professa]

I don’t think you can have a device that has normal charging because of amp draw = normal, that looks normal on dcps, and isn’t detected by iTunes. That is really going to be parts, or charging cable or something, or it is boot looping with no image.

what do the backlight filters look like? Are you sure you have no image in addition to no backlight?

what does physical exam of the board look like?

will device boot into recovery mode and be detected?

is this a cellular or WiFi iPad 3?