iPad boot loop only when powered - brief flash loop when connected to USB - jailbreak gone awry? Received an iPad from a customer in an unknown state. Report was "does not power on". Device is out of warranty. It's the 1st generation iPad with a 3G chip.

Symptoms:


when connected to power only, device turns on and shows apple logo, then shuts down, this proceeds in a loop that lasts about 4 seconds
when connected to an Apple machine's USB port, a faint flash can be observed on the device screen every 7 seconds or so but the apple logo is never seen, device does not respond to any key presses
when connected to power only, holding the power button will put device into recovery mode, but it shuts off when disconnected, so it can't actually be restored


If this rings a bell with anyone, please let me know what you think the issue is. My guess is that the battery is dead, but am not sure why it would not behave the same when connected to a computer USB port or the charger.I have tried multiple computers, cables and ports.

Is it possible a jailbreak gone awry would leave a device in this condition, and if so, what , if anything, can be done? I do have various Apple machines and OSs available, and PCs as well.
Jailbreaking only affects the operating system level of an iPad; it can't damage a device more than can be fixed by putting it into DFU mode and restoring it with iTunes.

In other words, it sounds like this device has a hardware problem of some kind.