Alienware X15 R2 LA-L611 No power

[randomrat]

Not having the best of luck with my own gadgets atm - I own two identical X15 R2 laptops, both have died suddenly with no prior issues. I have time to focus on one of them and in this post. I might need some hand-holding with this so I kindly ask for some understanding

Make: Alienware
Model: X15 R2
Motherboard: LA-L611
CPU: i9-12900H
GPU: RTX 3080Ti

History: I was using the machine as normal when it suddenly switched off and never came back on. I've owned the machine for over a year and use a Dell Thunderbolt Dock to charge my laptop with. This was connected along with a USB SSD when it stopped working. No water ingress, I keep the fans and grills meticulously clean. I use a genuine Dell 130W PSU into the Dell Dock.

I want to learn as well as fix this machine, but im not sure if I've handled the diagnostics and repair in the correct order. Someone has uploaded a boardview on Badcaps forum recently, credits go to them but I have posted it here if it helps for reference. I should mention from the beginning that I have replaced ISL9241HRTZ and the EC as I wasn't getting certain voltages. I regret replacing the EC without asking for help first, but I have the original EC still...it just needs reballing if I need to resolder it..


I decided that looking at the charging circuit was the best place to start. Measurements taken with USB-C PD charger connected and battery disconnected.

PUB1 (ISL9241HRTZ)

| Pin | NetName |
|-----|--------------------|
| 1 | CSON_CHG | 12.55v
| 2 | CSOP_CHG | 12.55v
| 3 | NGATE_CHG | 16.84v
| 4 | BST2_CHG | 6.67v
| 5 | UG2_CHG | 2.67v
| 6 | LX2_CHG | 1.62v
| 7 | LG2_CHG | 4.4v
| 8 | N17081747 | 5.054v
| 9 | LG1_CHG | 4.405v
| 10 | LX1_CHG | 1.625v
| 11 | UG1_CHG | 1.645v
| 12 | BST1_CHG | 6.67v
| 13 | BYPSRC | 0.58v
| 14 | CSIN_CHG | 19.66v
| 15 | CSIP_CHG | 19.66v
| 16 | BYPSG | 0.561v
| 17 | DCIN_CHG | 19.35v
| 18 | VDD_CHG | 5.065v
| 19 | PROG_CHG | 0v
| 20 | OTGEN/CMIN_CHG | 0v
| 21 | SDA_CHG | 0.446v
| 22 | SCL_CHG | 0.446v
| 23 | PROCHOT#_CHG | 2.256v (fluctuates a bit)
| 24 | ACOK_CHG | 3.35v
| 25 | BATGONE_CHG | 0.01v
| 26 | OTGPG/CMOUT_CHG | 0v
| 27 | COMPR_CHG | 1.189v
| 28 | COMP_CHG | 1.426v
| 29 | AMON/BMON_CHG | 0v
| 30 | PSYS_CHG | 0.02v
| 31 | VBAT_CHG | 0.525v
| 32 | BGATE_CHG | 0.395v (fluctuates a bit)
| 33 | GND |


I think I can take away a few things from this.

1) SDA_CHG and SCL_CHG should be at 3.3v, otherwise it most likely wont communicate to the battery or the EC.
2) LX1_CHG and LX1_CHG look abnormal at 1.62v. I replaced two dual N channel posfets Is it safe to inject 20v here?



Next thing i thought would be good to check is PU301 (TPS51225)
| Pin | NetName |
|-----|-------------|
| 1 | CS1 | 0.829v
| 2 | FB_5V | 0v
| 3 | +3VLP | 3.299v
| 4 | FB_3V | 0.018v
| 5 | CS2 | 0.565v
| 6 | 3V_EN | 0v
| 7 | POK | 0v
| 8 | LX_3V | 0.031v
| 9 | BST_3V | 4.821v
| 10 | UG_3V | 0.031v
| 11 | LG_3V | 0v
| 12 | 3/5V_B+ | 12.56v
| 13 | +5VLP | 5.011v
| 14 | +5VALWP | 0v
| 15 | LG_5V | 0v
| 16 | UG_5V | 0v
| 17 | BST_5V | 4.821v
| 18 | LX_5V | 0vv
| 19 | VCLK_5V | 0.07v
| 20 | 5V_EN | 0v
| 21 | GND |

The 5v and 3v enable lines are tied together. These are at 0v so it's not turning these circuits on. This comes from the EC - I purchased this from a supplier who said it could be loaded with the correct fw.

The GPU looks like it's a dead short at 0.5 Ohms, but i've read up that this is normal for these chips...I did inject 0.3v to vcore at one point to see if the GPU driver MOSFETS were shorted to ground. I saw no signs with a thermal camera.

Prior to replacing the EC all i got as 6mA draw from my USB-C ammeter, after reflowing it I had the same value. After replacing the EC with another I now get 0.042mA.
I think the issues lie with the EC because I believe its responsible for I2C comms to ISL9241 and it should enable the 3v and 5v rails.

I'm a little lost and some advice would be great. Thank you

[mon2]

Study the Power Sequence (S3 -> S0) on sheet #5 of the schematic.

What is the voltage to ground of ALW_PWR_EN?

[randomrat]

Study the Power Sequence (S3 -> S0) on sheet #5 of the schematic.

What is the voltage to ground of ALW_PWR_EN?

Thank you so much for a response.

Sorry, but I can't find the schematic. I have only found the boardview. Someone else requested it on the forum but had no response. I'll look again.

ALW_PWR_EN is 0v. From the boardview, it seems that this signal is generated by the EC?

EDIT....I think I have found the schematic, but it looks like i've fallen at the first hurdle!!

I get 3.3v for VCIN1_AC_IN, but then the EC should spit out ALW_PWR_EN. Guess the EC I bought is not performing as it should..? Surely even without an appropriate firmware loaded it should give out a signal for ALW_PWR_EN?

[qayyum786]

I am not sure its a same one or not. Maybe it will help you

you may check the schematic and update if it is match

[mon2]

Surely even without an appropriate firmware loaded it should give out a signal for ALW_PWR_EN?

No. The EC is a stand alone microcontroller based on 8051 or Cortex M0 or similar. Either way, the microcontroller requires working firmware to make this component operate as a keyboard encoder; power supply monitor; power supply sequencer, etc. based on the requirements. Otherwise, the referenced pin is just a GPIO (general purpose input/output) pin that has no smarts so is doing nothing. The premise here is that this EC is being properly powered and was properly soldered onto the board.

Start with confirming that the EC is being powered and do inspect each solder short. If available to you, check under a thermal camera to confirm the part is not being shorted.