Dell XPS 15 9550 -- No power on, no battery lights

Hi all,

I have a Dell XPS 15 9550, quite a few years old. Tried to turn it on yesterday and nothing. Button doesn't turn it on. If I press the battery light button the side, no charge lights appear. I assume the battery is dead as I haven't used it in a few months.

It IS plugged in to the wall. Left it on all last night and still no sign of power.

I'd like to try and fix it. Any suggestions on culprits? Could it be the power port inside the laptop?
Any diagnostics I can try? Thank you!

 

Are front LEDs blinking?

https://www.dell.com/community/Lapt...-15-9550-2-orange-blinks-4-white/td-p/5103680

 

Is the white light at the end of the power brick cord illuminated? If not, make sure the cable that connects the brick to the wall if fully seated. And make sure your wall outlet is working (you can test the wall outlet with a regular lamp).

 

Nothing - no lights anywhere. Its completely dead. When I push the power button, it doesn't illuminate either, so its definitely not trying to start.
I'm under the belief its not starting because the battery is completely dead though, it hasnt been used in many months....but even a dead battery should start if its plugged in, which it still does not.

Yes LED on power cord is illuminated. Not the outlet.

 

You can find the service manual in the link below. I might start with a visual inspection of the battery & connections. Overall visual of the board. Visual of power input section.

Maybe try disconnecting the cmos battery for an hour.

https://www.dell.com/support/home/en-us/product-support/product/xps-15-9550-laptop/docs

Some visuals and sample voltage values here. Not sure if fix was removing the cmos battery or poorly seated RAM (plus I can't tell if this is the 9550 so use caution with the video)...

 

Thanks - that video gets me closer. I pulled the CMOS battery (what a colossal PITA - never dell laptops again) and now the battery light and power light does come on for a few seconds but unfortunately it turns off and stays off. It will turn on again if I press it but waiting a couple of minutes like he did didn't help - it isn't cycling. Tested with a fully charged battery and without power and with power and without a battery and with both - no luck. I've tried reseating the memory no luck. However the cmos battery pull and plug did seem to get that light to come out which is more than before. Still no fan movement.

I'll leave the cmos unplugged for the day and see if it changes anything.

 

Try just one stick of RAM alone. If that doesn't work, try the other stick alone. If you have other compatible RAM try that. Also, try removing the SSD and reinserting.

You might clean the Gold contacts on the RAM and nvme drive with iso alcohol, preferably 99%+. My buddy ran a huge farm of desktops and dirty memory contacts was a significant cause of failure. After cleaning the RAM and SSD contacts, never touch those contacts. Do NOT touch or try to clean the delicate pins of the RAM/SSD connectors as you will bend them.

Whilst you have the system apart, you might disconnect and reconnect the easy to access connectors. The screen connector on my laptop worked itself loose and was difficult to diagnose.

For the CMOS battery, some people wire an on-off switch that is easy to access to make troubleshooting easier.

Get a loop and look really carefully for any damaged parts, soldier joints, green contamination.

 

Thanks - I tried the memory - no luck. I haven't tried the HD. I've ordered a spare cmos battery for the heck of it - $8 won't kill me if it helps me diagnose it.

I'll try cleaning if that doesn't help.

 

No luck cleaning, replacing the HD or memory - I press the power button and the light goes on for a few seconds and off again. I've tried 1 stick of memory, reversing them, making sure they are clean, removing the HD, putting it back in - still just the power button for a few seconds and then it goes off. I've also done this with just a battery, no battery - same issue.

Fans never move even 1 degree and they are clean. The inside of this laptop was remarkably clean.


PS - after spending a lot more time on it, I realized it was time to move on to acceptance and get a new laptop.

Thanks everyone for your help.