Diagnosing my water damaged Dell XPS 9530 (Part one)

Water, water everywhere!

My Dell XPS 9530 was recently the victim of an unfortunate incident involving a mug of water. The outcome, a not very happy and bleepy (beep codes) Dell laptop. While I’ve opened a lot of electronics in my time, I hadn’t up until this point ever needed to do it specifically for water damage but hey there’s always a first time for everything right?! Join me on my diagnosis and assessment of what a water spill can do in a very short space of time to electronic hardware components.

Assessing the damage

Popping off the bottom case to inspect the initial damage. Initially it doesn’t look too bad. There are signs of corrosion below on the PCB below which is the I/O daughterboard for the SD card reader/USB ports (right side), the tell-tale sign is usually discolouration around chips or capacitors where current flows through.

A visual inspection shows we have the immediate signs of water damage on this PCB. There is also discolouring on the felt like material covering the part of the USB ports, which further confirms enough water got onto this PCB to potentially do some nasty stuff.

Corrosion on the daughter board

Taking the daughterboard out of the laptop case entirely we see there are further areas where corrosion is present on this PCB.

  • The WiFi connector at the very top has some corrosion on a few of the pins on the left side.
  • The CMOS battery connector has some minor corrosion, visible as a blueish blob.
  • The Texas Instruments USB controller chip has a fair bit of corrosion on itself and the surrounding area. USB is potentially dead on this PCB now.
  • The connector port for the ribbon cable has a fair bit of corrosion

Looking at the I/O FPC cable that goes between the daughterboard and the main logic board, we also see further corrosion, which is not surprising given the state of the connector on the PCB itself.

The mSATA SSD seems to have also got a minor bit of corrosion on itself on both sides, but it looks relatively minor. On the label side towards the bottom left. On the under side, top right. The pins going to the connector look OK however.

Front side of the mSATA SSD. Some evidence of corrosion towards the bottom left.
mSATA SSD reverse side. A small bit of water damage in the top right corner

The WiFi card also has some discolouring on some of it’s pins, which match to the places where there is damage on the pins to the connector on the PCB. There are also signs of scorching/burning on the pins. An indication that power was travelling through when water hit this component.

Intel AC 7260 WiFi card, the pins looks a bit sorry for themselves.

Although initially it looked like the main logic board had escaped any water damage, there might be a tiny bit of water corrosion towards the top section, near a chip marked TI 87352D which appears to be a MOSFET buck power block.

Damage from the water can be seen on the laptop casing and the back surface of the keyboard, mainly around the right side fan area (which is actually on left because the laptop base is inverted), but this looks more like minor cosmetic damage. The connectors and cables seem OK.

The bare laptop casing revealing where water managed to get to.
Laptop inside casing with water damage.

Summary of the damage

From examining the visual signs, this is my assessment.

  • The daughterboard PCB took a lot of the punishment. Several connectors and areas have likely been damaged. In particular the USB controller area and connector for the IO FPC cable looks nasty. I am going to replace this entirely as I don’t trust it now even with cleaning.
  • The connector on the IO FPC cable itself doesn’t look too healthy either, I am also going to replace this part also to be sure.
  • The main logic board may have some corrosion near a MOSFET power block. The state of the main logic board is currently unknown, but will now be cleaned in the area where water seems to have got to it.
  • The mSATA SSD has minor corrosion but looks OK in all critical areas, cleaning it up and then trying to read data from it with an adapter will confirm if it is still working and trustworthy to store data.
  • One of the CMOS battery cable pins that go into the connector seems to have been corroded, likely from water getting onto the connector on the daughterboard PCB itself and because it is a battery, power will have always be been going through this. As the CMOS battery is relatively inexpensive to replace, I’ll be doing just that.
  • The WiFi card has some discolouration and scorching on the pins. Potentially with cleaning this may be salvageable, depending on how much of the corrosion can be removed without damaging the contact pins themselves. If not, replacing the Intel AC 7260 WiFi card is not that expensive.
  • Under the right side fan area there is residue from water, whether or not the fan itself was shorted out is unknown. The connector for FAN2 on the PCB didn’t look in bad shape, but I can’t be sure until it is powered again.

Everything else for the most part seems OK visually. The main logic board does have a tiny amount of water corrosion but I’m hoping this can clean off and hasn’t caused permanent damage, otherwise this would need to be looked at by a professional for possible rework/soldering, or at a really worse case scenario, replacing the entire logic board.

The last time the laptop was attempted to be powered on after the water spill, it was throwing two beeps. Looking at the official troubleshooting information from Dell, two beeps indicates a RAM issue. That is interesting, because water doesn’t seem to have gotten to that part of the logic board and there are no visual indications of damage there. It’s possible the RAM could have been fried, the memory slots are damaged or a circuit on the logic board is shorted but given the water corrosion in multiple places it could also be slightly misleading, so I’m not giving up yet!

Until I receive all the replacement parts and test one’s that may have survived for potential re-use, I don’t know if any other components got taken down with it.

My repair plan

I have decided to replace three components entirely due to the amount of corrosion and looking at areas the water has likely damaged. These are:

  • The daugtherboard for USB and SD card reader
  • The IO FPC cable
  • CMOS battery

I’ll be cleaning the following components with the hope they weren’t permanently damaged:

  • mSATA SSD
  • Intel 7260 AC WiFI card
  • Area on the logic board around the MOSFET power block

I may have to look at replacing additional components, depending how unlucky I am, but I can start with the main areas I know will be likely bad and proceed through.

To clean these components properly I’ll be using 99% isopropyl alcohol to remove any corrosion on them. Using the cotton ear buds trick to apply and clean each component and the areas with corrosion.

For now most of the components with the exception of the display assembly have been removed from the laptop assembly entirely and left to be aired out in a dry area with a dehumidifier running for a while.

The water damage was mainly contained to the back right hand side of the laptop so this gives us the likely area where the most damage will have occurred. Potentially we are looking at a best case scenario of only needing to replace a few parts. Potentially more if cleaning the other components with isopropyl alcohol isn’t enough to make them work again. Although it will be unknown until power goes through all components again to find out if anything else has been damaged/shorted out.

I’ll follow up with a part two when everything has dried properly and replacement parts from eBay arrive. Due to some coming from outside of the UK, there will be a bit of a delay, but this is OK as the components need to be aired out and dry off properly and I can do some of the alcohol cleaning on other parts and test them while I wait.

Special thanks to iFixit and the repair community for the tear down guides. I’ve owned a few XPS models over the years so I’m fairly familiar with the layout, but it is always nice to have detailed tear down guides available!

https://www.ifixit.com/Device/Dell_XPS_15_9530

I'm a web developer, but also like writing about technical networking and security related topics, because I'm a massive nerd!