Dell XPS-15 (9520) Mostly Bricked after common BIOS-Firmware upgrade - Full Repair Log

[m1ch43lzm]

2. I mean physical damage just by the pressure/trying to fit that SOIC8 clip (the spring is too strong in those clips)

3. Watch parts-people videos, he does that all the time, for the USB-C powered laptops he uses an inline USB-C meter which shows voltage and current draw; for the other laptops with DC jack he built a pass-through box with a voltmeter/ammeter display, where he uses an original Dell charger

4. Comparing the BIOS region on your backup with 1.6.0 it looked fine, except NVRAM, that's expected since a clean BIOS will have default settings
Focus on returning to "Dell logo and not posting" since that was the original fault

Does holding "D" key and pressing power button show screen test where it changes colors?

I have to sleep now... it's 23:24 here

[Tesla]

2. I mean physical damage just by the pressure/trying to fit that SOIC8 clip (the spring is too strong in those clips)

3. Watch parts-people videos, he does that all the time, for the USB-C powered laptops he uses an inline USB-C meter which shows voltage and current draw; for the other laptops with DC jack he built a pass-through box with a voltmeter/ammeter display, where he uses an original Dell charger

4a. Comparing the BIOS region on your backup with 1.6.0 it looked fine, except NVRAM, that's expected since a clean BIOS will have default settings
4b. Focus on returning to "Dell logo and not posting" since that was the original fault

5. Does holding "D" key and pressing power button show screen test where it changes colors?

6. I have to sleep now... it's 23:24 here

2. Oh, maybe but I don't think so.

3. Yeah, he's amazing. He obviously has better equipment and more experience than me. He makes it look so easy. But sure, I'll try to watch some more (but I think I already watched them all before I decided to try this in the first place).

4a. Good to know.
4b. Funny, that's what I was thinking (see below)

5. No, not any more. Not since I re-wrote the rom that first time.

6. Same here. Sure no problem. Thanks again for all the help and discussion.

I guess what I'll do next ... I think it will alleviate these concerns that you have brought-up, mainly ...
- Is the T76 working properly
- Is the MB rom chip not blown and still working properly
... I'll re-write the rom-chip back to what I started with.
See if I can get back to Dell-Logo, LEDs turning-on again, Display-Test working again ... that sorta thing.

Sound like a plan?

[Tesla]

Test by plugging in the bare minimum: keyboard, screen, power button, 1 RAM stick

Interesting.

It would save time. Especially when just installing MB for a quick-test (needing to use the display and keyboard and their short cables).

What about the I/O-Board this one has. Looks like it facilitates SD-Reader, FingerPrint-Reader and Headphone-jack. You are saying it is OK to turn the machine on without it even connected?

[Tesla]

Before I get to "the real test" I had the opportunity to do this one...

I thought it would be a good-test of T76 operation, my technique, (and ROM-chip I would think).

I removed the MB after the v1.5.0 BIN you uploaded for me did not work either.
I read the rom-chip. It verified properly.
I saved at as test1.BIN (with FLASH option as usual)
I then file-compared it (with SHA256) with the original v1.5.0 BIN file you sent me.
THEY ARE BINARY IDENTICAL.

Seems like a lot of things are working properly and done right to make that happen.
What do you think? Good and relevant test?

[Tesla]

Focus on returning to "Dell logo and not posting" since that was the original fault

I removed the MB
I Erased and Blank-checked the bios-chip

- Loaded my original backup-file of the rom (the one I sent to yall originally)
- I wrote it to the rom-chip and it Verified properly.
- I notice the checksum displayed in the XgPro-log is the same as before when I was working with it.

I re-installed the motherboard in the minimalistic fashion as you recommended.

Still no display . No Dell-Logo displays like it did before.

What does that mean?

[m1ch43lzm]

Power button is on fingerprint reader, JFP, located under I/O board (card reader/audio jack), and keyboard + touchpad + front LED go first to another board, then there's a cable that goes from this board to the motherboard

I/O board can be left removed for testing
Display connector is near GPU side, JEDP1; you can skip JCCD1, that's for the webcam

Power sequence is at page 5 of schematics, you have to familiarize yourself measuring voltages on the motherboard
Also worth getting one of those USB-C meters, like this one for example:
https://www.amazon.com/YEREADW-Multi...DFBSFL38/?th=1
USB-C complicates things, you need to check if the board negotiates 20V from the charger, and the current draw when powered on

[Tesla]

1. Power button is on fingerprint reader, JFP, located under I/O board (card reader/audio jack),

2. and keyboard + touchpad + front LED go first to another board, then there's a cable that goes from this board to the motherboard

3. I/O board can be left removed for testing

4. Display connector is near GPU side, JEDP1; you can skip JCCD1, that's for the webcam

5. Power sequence is at page 5 of schematics, you have to familiarize yourself measuring voltages on the motherboard

6. Also worth getting one of those USB-C meters, like this one for example:

7. USB-C complicates things, you need to check if the board negotiates 20V from the charger, and the current draw when powered on

1. If you say so. From the top, it appears to be part of the keyboard.
But if as you say ... do I just pickup a FP-Reader/Power-Switch on eBay to help facilitate being able to power-up the MB on the desk (fairly bare).

2. Correct.

3. Thanks for confirming.

4. Good info. So, I wonder about the Touch-Screen cable (pretty-sure it had 10-point Touch).

5. Thanks, I'll take a look.

6. Yes, I have one. It does all the USB-types and looks like a cross. Never really used it but docs say it's USB-C works on laptops (high watts). Your linked-one is nice too for only $10.

7. Acknowledged.

[Tesla]

Million-Dollar Questions:

a. With all the Erasing, Writing, and Verifying apparently working ... do you think the ROM chip is still OK?

b. What happened here. Did I damage it or did the T76?

While I am tempted to scrap it for parts, I'm not sure what I would do with most of them. The SSD and large/powerful USB-C AC-Adapter/Charger is all I have a use for at the moment.

I hate wasting-money (and good tech) but I don't really need money to where I would bother "parting it out" on eBay. I was more interested in getting this "high-end laptop" working again just because (as a whole) it was nice. If I had a friend who needed the Display-Unit or Battery, I would just give it to them. In fact, I just found a local computer shop down the street. If I can't fix it (or just give-up and use my "still working laptops") I think I'm going to just give it to him for parts (online, looks like an older dad with kids to feed). I would just say ... my time has come and gone and I'll leave this stuff to the younger ones, their hot-air-wands, and their microscopes.

Still being able to do a bit of coding, Motherboard-Swapping as needed (when financially feasible on said machine), design and installing Omada computer networks, build and fly DIY drones, build and program Virtual Pinball cabinets ... is not such a bad skill-set for an old-guy.

But if I'm going to progress from a "motherboard swapper" and try to get my skills back to the level during the 1990's (when everything was bigger and simpler) well, a laptop like this sure is a good candidate. Train on this (and hopefully fix it). But also be ready for the next nice/expensive UltraBook laptop, nice monitor, large 4K TV, High-end AVR, computerized appliance (yes, I have before), automobile (I also fixed a 1994-Honda engine-computer motherboard once) ... whatever the nice expensive machine is ... I would be more prepared.

Your thoughts ... especially on item A above, but also B if you have some idea. I would like to know and avoid in the future.

[Tesla]

USB-C complicates things, you need to check if the board negotiates 20V from the charger, and the current draw when powered on

Multi-USB Tester:
Says 20v at 0.11 amps when I plug-in AC-Adapter
0.26 amps (after I manage to get it to turn-on, holding down the Power-Button for a few seconds)
Stays at 0.26 amps until it turns-itself off (about 20 secs later)
This is without the battery installed.

[m1ch43lzm]

a. Yes
b. Something got damaged for sure, I can't tell without proper measurements

Multi-USB Tester:
Says 20v at 0.11 amps when I plug-in AC-Adapter
0.26 amps (after I manage to get it to turn-on, holding down the Power-Button for a few seconds)
Stays at 0.26 amps until it turns-itself off (about 20 secs later)
This is without the battery installed.

That's too low for this laptop at least, you should get above 1A i think when powered on; for reference an XPS 17 9700 (i9/RTX 2060) draws around 2-3A when idling at Windows desktop and a fully charged battery
Maybe a voltage or signal is missing and it's stuck somewhere in the power up sequence

I hate wasting-money (and good tech) but I don't really need money to where I would bother "parting it out" on eBay. I was more interested in getting this "high-end laptop" working again just because (as a whole) it was nice. If I had a friend who needed the Display-Unit or Battery, I would just give it to them. In fact, I just found a local computer shop down the street. If I can't fix it (or just give-up and use my "still working laptops") I think I'm going to just give it to him for parts (online, looks like an older dad with kids to feed). I would just say ... my time has come and gone and I'll leave this stuff to the younger ones, their hot-air-wands, and their microscopes.

Depends if your local computer shop does motherboard repair/microsoldering and has all the proper tools (the "hot airs and microscopes"), or only does part swaps and regular service (cleaning fans, thermal paste, OS reinstall, etc.), ask them first

[Tesla]

a. Yes
b. Something got damaged for sure, I can't tell without proper measurements

a. Thanks for confirming that.

So yeah ... I'm going to keep (not return) my new XGecu-T76 as I think it's cool. I've always wanted my own (since I used the company's old-school "rom burner" back in the 90's). But if me and Mr.T76 can't fix the next machine either (or we make it worse again) I think he might be going into the trash-can.

b. Agreed, but that's what bothers me. It might not sound like it, but I actually know what I'm doing. There is no reason why some other component should have failed.

But it's an adventure right? I appreciate finding out (I never would have know without you catching it) , but also dismayed to find that Intel ES-CPU Engineering-sample on the motherboard. A easy or quick-fix (rom re-write) is one thing, but not worth having it professionally repaired (with the limitations is imposes and all). Even kinda-kills the idea of me spending a lot more time on it try to fix it. I would want to "use it for real" and I'm kinda picky about my computers and OSes (like, I don't know ... they need to be actual release versions and not betas).

[Tesla]

b. Something got damaged for sure, I can't tell without proper measurements

Using the BoardView and an ohm-meter, I checked that all 8 pins are still connected (using the surrounding components to check continuity).

The pogo tool scratched the leg/pads a bit, but did not seem to damage any traces. Just seemed like a good/basic thing to check since everything is just "normally, barely soldered on".
But no problem found ... the 25R512JVEN ( UH8) is still soldered-on properly. Looking with a magnifying glass around there also ... all looks fine still.

Also strangely ... large sections of the board are covered with black specially-cut very-sticky tape-like sections (especially on the back here).
It's fairly obviously they didn't build this to be "worked on".

[m1ch43lzm]

Maybe you connected the pogo pin adapter the wrong way once, tried to read the chip, then realized afterwards?
The "black plastic sheet with sticky tape in sections" works as electrical insulator most likely, you don't want to short the components on the back side of board to a metal chassis (and behind the keyboard should also be covered with some type of plastic insulator too); that could also help partially containing liquid spills

I also notice Dell added a "SPI tamper proof circuit", page 9 of the schematics; looks like when there's no power to the board it pulls down PCH_SPI_CS#0_R ; but I don't think it's relevant as you are able to read/write the BIOS chip

Without power applied, start by measuring resistance to GND at the coils, take note of the values

[Tesla]

Check it out dudes. This nicely-configured XPS-15 might live-again after all.
I told yall that I really DO KNOW (well sorta) what I am doing. 😄 But I don't want to jinx-it ... so treading lightly here. Let's see how far I can get.

https://www.badcaps.net/forum/troubl...42#post3849142

[m1ch43lzm]

You're almost there, as for the service tag, since yours is a prototype just make one up or enter 1234567 (unless it had one set before), retail units have it on the bottom cover, it's either laser etched (metal bottom cover) or placed on a sticker (plastic cover), or "borrow it" from another XPS 9520...
The rest leave as is, don't mess with ME or TPM settings
Some things to keep in mind: I've seen posts on BIOS request forum for some Dell laptops, that after entering ST, laptop doesn't power on again, usually after unlocking BIOS password with a patched BIOS, it depends if the BIOS was patched correctly in that case
Flashing the same BIOS allows it to boot again in Manufacturing mode, another common issue is that the ST doesn't get sdved

* You can also press F2 to enter BIOS setup when on the Manufacturing mode screen

* Not sure about Dell, whether you can boot into Windows when it's on Manufacturing mode, never done that on a Dell; HP will display "Manufacturing Programming Mode is in Unlock Mode" each power on, but will boot into Windows afterwards, and Lenovo will boot but s/N, model, etc show as INVALID

[Tesla]

Looks like the XPS15-9520 is really back from the dead. It's been running fine and not doing anything weird.

Luckily, the Service-Tag/Manufacturing-Mode thing worked normally and by design.

While it was dead, I tested its Samsung OEM-990 4x4 NVMe SSD in my new little USB-3.2 SSD Tester, but resisted the urge to mess with it much. Turned-out to be the right decision as (back in the laptop) it booted-up fine and Windows-11 said it was till Activated ... so I was able to retrieve/backup that Windows-11 Pro key/license after all (so now I have it in case of another disaster).