Dell XPS 9550 Black Screen, no Dell logo after failed Windows 10 Update

Can anyone help me on this?

Do you have any idea what update it was?  If it showed up on the 21st it was probably KB4015438.

I think I saw that update was supposed to correct something in an earlier update.

What does the light in the power button do?  F12 is supposed to allow you to boot into the Diagnostics, if that system works that way.  Since I am not familiar with that system, did it come originally with Win 10?

Have you tried an external monitor?  Have you tried booting to some external media like a Ubuntu live version or a recovery drive or Windows Install Media?

It doesn't detect any peripherals so cannot boot from USB drive either.

I cannot remember. But the machine doesn't POST. Just a black screen.

A black screen like that normally happens after the bios page.  With Win 10 it can be problematic getting into the Bios.  So when you start to boot, much earlier than you might think, start tapping the F2 key just to see if you can get into the bios.

I have seen a black screen after a Windows update where it is configuring something and stayed black for 10 to 15 minutes.  Do you feel it has had time to finish whatever it might have been doing?

I have seen situations where a bad drive would keep the bios from being accessed.  If that were happening, removing the drive, if you have that capability, might help.  Did you have any indications of a failing drive prior to this time?

Do the same steps to enter the BIOS (F2 key)

The problem is I cannot get it to POST. Hitting any keys repeatedly is unresponsive. The CAPS LOCK LED is also not being toggled. It suggests to me the motherboard software seems to be corrupted(?)

I was on phone call with Dell support they said my motherboard was fried. I fail to believe how a failed "software" Windows 10 update can cause failure to "hardware". So I understand that Windows 10 is more tightly coupled with the hardware. Is this the cause?

The laptop is a huge paperweight now. No key combination is making it show the Dell logo after hitting power button!

It appears that a BIOS update cause the problem, furthermore you aren't able to use the F2 key(BIOS) and F12 (diagnostic) is one of the signs of a failed system board. However, a fail hard drive ( or SSD drive) sometimes will do the same thing. If you're comfortable in opening the computer, I suggest you remove the hard drive cable from the system board (motherboard}. Please follow steps below:

1. Remove all the external peripherals (printers, scanners or any other USB device) connected to your computer.

2. Please remove the AC adapter and battery of your computer. Press 'Power On' button for about 15 seconds to drain the residual power.

XPS 15 9550 Service Manual

If reseating the hard drive assemble doesn't work, I suggest reseating the motherboard battery (coin -cell battery).

1. Power off system. Remove adapter and battery. Press 'Power On' button for about 15 seconds.

2. Remove motherboard battery. Press 'Power On' button for about 25 seconds

3. Replace motherboard battery. Note: It might be a good ideal to purchase a new one at your local Walmart for about $3.00.

4. Replace battery, adapter, and then power on system. Hopefully computer starts normally.

XPS 15 9550 Service Manual

3. Remove Hard drive cable from motherboard

4. Remove hard drive assembly. Press the 'Power On' button for about 10 seconds.

5. Replace hard drive assembly and then connect cable to motherboard.

6. Replace battery and AC adapter,  and then power on system, Hopefully system starts normally.

If you aren't comfortable in opening the computer, I suggest you contact Dell Expired Warranties in the link below and ask for a quote.

Support Service for Expired Warranties | Dell

So having attempted to do the above, they said I damaged the screws. I paid for NBD for Dell to fix this and they write this email to me:

"Greetings of the day. Thank you for your email. The fact that the engineer could not remove the screws confirms that there has been damage that does not let us perform repairs on the computers as suggested. Any consumer unit less than 2 years of age, purchase directly from Dell qualifies for hardware replacement for free as per the Statutory Rights. This was the reason for us to send out an engineer without you having to pay for the part. Since external damage was identified on the unit Statutory Rights would not be applicable and we hence would not be able to collect the unit for the mobo to be replaced without additional charges.

We understand that the unit would not post, however this, as confirmed by tech support is a hardware issue that requires the motherboard to be replaced for resolution. We were not able to replace the same due to the damage on the screws which would not let the engineer disassemble the unit to replace the motherboard.

Articles on the internet cannot be considered as evidence to fix issues under warranty as they are open forums and anybody could express their views on it. In regards with your request for further escalation, we regret to let you know that the Customer Relations team is the final point of escalation from Technical Support and we would not be able to escalate any further. Dell’s position in this matter will remain the same."

Do I have a leg to stand on this? they are saying I need to essentially pay £1000 ~ $1200 USD for a mobo replacement. This is unbelievable. I am essentially needing to cough up about 80-90% of what I originally paid for this brick.