Laptop no boot

[jaydee]

A family member has a Dell Latitude E7440 we bought used from Ebay about 6 months ago. It was fine until about a week ago, when it stopped booting up (battery or power supply plugged in). By not booting, I mean nothing: nothing at all on the screen, fan audible for a couple seconds, then dies down.

I took off the bottom cover and noticed that when I pushed the power button, the fan turns on for a few seconds, then dies. Hit the power button again and the same thing. I pulled the hard drive and battery, unplugged the power supply and held the power button on for ~30 seconds to drain the capacitors (so I've read): no change. I've reseated the RAM: no change. I've disconnected and reconnected the CMOS battery: no change.

Sounds like the motherboard and/or CPU fried? Any other troubleshooting that can be done before I try to find a new motherboard?

 

[corkyg]

Try reseating the processor.

 

[DAPUNISHER]

Get another power supply for it, if it does not work, you can always return it. Having seen it be responsible for the symptoms you describe, it would be my last step (along with a different stick of ram) before looking for a replacement board. If it has 2 sticks of ram, try them one at a time.

 

[jaydee]

Get another power supply for it, if it does not work, you can always return it. Having seen it be responsible for the symptoms you describe, it would be my last step (along with a different stick of ram) before looking for a replacement board. If it has 2 sticks of ram, try them one at a time.

Would a bad stick of RAM cause the laptop to not even get to the BIOS splash screen though?

 

[DAPUNISHER]

Would a bad stick of RAM cause the laptop to not even get to the BIOS splash screen though?

Dead stick is perhaps a better term for it. Pull all the ram out of a system and try to boot. A dead stick does the same thing. Faulty ram exhibits other symptoms.

 

[jaydee]

Right. So I did pull the (only) stick of RAM out of the system last time I was over and tried booting and there was no change in behavior. For some reason, I was expecting, even with bad RAM/dead RAM/no RAM I could at least see the screen start to light and the fan would run for more than a few seconds, but I could be incorrect.


BTW, I'm not ignoring the suggestion to re-seat the CPU, just haven't been over to their house since the original post to try this yet. Actually, I think the CPU is soldered on, but I'm still trying to figure this out.

 

[corkyg]

The reason I mentioned it because my bro flies, and the laptop sat on the cockpit floor, and the vibrations of the plane over time caused the CPU to slightly back out. The result was about as you described.

 

[jaydee]

Thanks for the info. Do you happen to know if the E7440 has a CPU that is "re-seat"able though? All the indications I'm seeing online, makes me believe the CPU is soldered on and can't be adjusted.

 

[Burpo]

$79 on ebay with cpu..

https://www.ebay.com/itm/Genuine-De...902791&hash=item33e1b52384:g:9DkAAOSwNt1afHUH

 

[jaydee]

The reason I mentioned it because my bro flies, and the laptop sat on the cockpit floor, and the vibrations of the plane over time caused the CPU to slightly back out. The result was about as you described.

$79 on ebay with cpu..

https://www.ebay.com/itm/Genuine-De...902791&hash=item33e1b52384:g:9DkAAOSwNt1afHUH

Ya, that's been in my watchlist. Can I just replace this mobo/CPU, using the same hard drive as before, and expect everything to work fine? Or would I need to re-install Windows? It's a different CPU, old one had i7-4600U

 

[Burpo]

Yes, it should work fine with old drive, no need to re-install Windows..

 

[Jürgen Ender]

Its a different possibility, but i had an equal problem.
My problem was that the battery pack was dead, i tried to start it without the battery and it worked.
Or as DAPUNISHER said, try a different power supply.

Also if the ram is defect it should make a BIOS or POST beep sound.

 

[ch33zw1z]

Its a different possibility, but i had an equal problem.
My problem was that the battery pack was dead, i tried to start it without the battery and it worked.
Or as DAPUNISHER said, try a different power supply.

Also if the ram is defect it should make a BIOS or POST beep sound.

This last part isnt necessarily accurate. I repair many x86 workstations, including laptops. You don't always get a beep sound if the ram is bad, in fact it's more often I see the "no post, no video"

Here's a recent example, brand new Lenovo t470, no post no video...

*Each time i make a change, the AC is disconnected, and no batteries installed

1. Unplug both batteries , no fix
2, unplug m.2 ssd and WiFi card, no fix
3. Pull memory dimms, no fix
4. Unplug cmos battery, I get post errors now
5. Put a single memory dimms in, no post no video again, move this dimm to slot 2, same thing
6. Put other dimm in slot 1, posts and get Lenovo spalsh screen ok, move this dimm to slot 2, works fine

Basically, ends up a failed dimm on a new device was causing no post no video.

Also, same type of machine, same place. Just repaired another because it wouldn't post, no video.

I followed the same basic steps, and no post still...system board was dead.

 

[jaydee]

Thanks guys. I did end up replacing the motherboard and is everything is now working but the sound. Have to troubleshoot that now, not sure if its a problem with the refurb motherboard or I missed a connection when I put it back together.

 

[Ankur Saxena]

Remove the RAM dust and then try or change your processor.