Hi guys, I've searched around here and a few other forums and haven't found any specific solution to this problem yet, but here's what's going on:

Midway through a trip this past summer (While back yes, I totally forgot about troubleshooting as I wasn't using the unit often) my TT XL seemed to switch off. At the time I assumed it was a battery issue, or else it was overheating somehow, since it was summer. Upon getting it back to my PC i found the following:

1) If I soft reset it, the power up drum jingle would play, but nothing happens on the screen.
2) If I plug it in via USB and soft reset it, the power up drums play, and TT HOME detects it, will update it, back up, and so forth. I can also use the Operate Device feature from it.

TT Tech support advised a series of updates, soft resets, the clear flash utility and so forth, none of which seem to have changed the behavior at all.

All these things make me suppose that there's a hardware failure, either the screen device or a connector or something, but having read around here and become a little familiar with things like bootloader and navcore, I'm wondering if changing those might help. If any of you have anything to advise, I'll be glad to try it, cause at this point there's not much to lose.

My configuration is this (If I missed any important lines please let me know)

DeviceName=TomTom XL
DeviceVersionHW=ONE XL (v9)
DeviceUniqueID=
RamDiskVersion=20090817
BootLoaderVersion=55136
LinuxVersion=343369
ApplicationVersionVersionNumber=8083
ApplicationVersion=9669
UserLanguage=English US
LastConnectionTime=Never
GPSFirmwareVersion=
CurrentMapVersion=850.2824

I have never seen a navcore or map problem that will cause a black screen.

You hav to check if the power button seem to be "always on":
I explain:
You have a small switch on the motherboard to switch it on/off.
Ths power button is supposed to get back to it first position with a thin plastic (wich have to do be as a spring with the power button).
Some times the "spring" is over and it do no more his work to push back the button.
The GPS is starting with the button "start" alwas pushed.
This make some problems to use the tomtom

Some possibilities :
The screen is set to night view with the lowest setting - but than you should still the boot screen.
It could be the driver for backlight - in that case you should see at least a little change on the screen when booting.
The screen or driver for it is defect - that includes a loose connection of the flat cable to the screen.
I don't see a software problem, it clearly is a hardware issue.
You can get replacements for screen and the touch unit on Ebay for a couple of dollars but you might have to search in the Ebay Hong Kong setion too.