Latitude e6400 NOT turning 'on'

I have a Dell Latitude e6400, running MS Vista (latest SP2 + updates).

It is running Bios A14 (recent update).

My issues are:
1. Computer will start up and work normally. However, on shutting down and restart, it will not restart
2. The 'on' button flashes every few seconds as if the notebook is 'trying' to start up and the HDD light flashes every so briefly. This recurs indefinitely.

The only way to 'fix' the problem is to unplug the charger, wait and replug it back in and after several tries, the computer will start and boot and load up Vista without issues.

The problem also happens when running / restarting on battery only and using charger only with no battery. I have run the pre-boot diagnostics (holding Fn / power button) and it does not detect any errors.

Is this a motherboard, a power circuit or BIOS upgrade issue?

 

Did the problem happen before SP2?
Also, try downgrading the BIOS to A12. If it doesn't help, you can isolate the problem.

I've never heard of this particular issue...

 

SP2 was installed quite some time ago on release and downgrading to A12 did nothing to improve the issue.

Dell are sending out a new power adapter although i don't think that will help.

 

It could be the motherboard.

 

I'm trying to persuade Dell that the motherboard may be at fault, but the Dell 32 bit diagnostics ran okay and it's very hard to get them to send out a tech.

Are there any other ideas of what could be at fault or to prove it so Dell send out a replacement?

 

Not really. This isn't an obvious/common problem. If something weird like this happens, my first reaction is software, then motherboard. The charger is a waste of time, and I'm about 99% sure that it won't help.

I would try setting all BIOS settings to default (reset defaults), also reset all Windows power settings.
As for SP2, did the problem occur before SP2, develop right after installing SP2, or develop after a period of time with SP2.

I don't really see anything that could convince them that the motherboard is broken, besides speaking to a tech and going through that whole convoluted process.

 

1. The problem developed quite some time after installing Vista SP2 and I doubt it is related.

2. Basically it's a power cycling problem.
- Shut down the computer (or restart)
- Fails to restart or power up on pressing the power button completely
- Battery LED and Power 'on' LED flashes on for 1-2 seconds, HDD light blinks (sometimes the fan turns on). Then everything cuts out again. A few seconds later, the same cycle of attempted power on happens agan.
- Computer fails to reach BIOS screen or POST.

Unplugging the AC adapter and plugging it back in seems to reset the cycle and the computer will then boot normally until it's shut down again. However, the problem also happens after shutting down both when it's running on battery alone and AC adapter alone with battery removed

I've also tried resetting BIOS to default, reflashing to A12, reflashing back to A14, reseating the RAM, removing battery/adapter for 30 minutes to no avail.

 

Had another chat to Dell customer service through online chat and we agreed it was the motherboard.

Chanaged today (amazing how easy the notebook is to take apart) - took 30 minutes. All fixed! Let's hope the Dell tech's disassembly and assembly technique didn't damage anything else.