Dell Inspiron 5520 BIOS recovery help needed

Yea, that’s the problem… The EC’s flash is not SOIC8 like the other 2 flash chips. It’s embedded in the EC itself, not a separate chip on the motherboard. This is why I tried the keyboard connector method, in theory it enables the EC’s flash access to it’s internal SPI with some debug interface.



I don’t know if CH341A can do more than I did with keyboard connector, because I can connect it only there, or somehow to EC’s pins directly. Or, maybe the EDI debug interface didn’t enabled itself when I tried earlier. I had connected pin 42 to ground to bring it in low state. Is there any way to check if EC is in debug mode or not?


Edit: Something I don’t understand. The datasheet says external flash, but there are videos on YouTube and guides on other forums where they modify the EC’s internal flash with this method…

And, maybe pin 41 should be connected to ground too?

EC FW is contained within a chip, but just not a SOIC type like the others. No problem, yes you’ll have to do the keyboard ribbon cable method.
That guide suggest CH341A as best way to do it, making me believe he had already tried other methods one shown on the guide, and found the best compatible one to use was the CH341A.
Like you mentioned, your method does not even detect the chip, so it can never work, unless you have some cable wrong or not securely connected etc.

I do not know how to check if it’s in debug mode or not. Best to follow that guide, and what was immediately apparent to me was he said best tool to use and what he used to write the remainder of the guide was CH341A, so I would get that before doing anything possibly destructive.

I will read about the internal / external flash thing, because the datasheet is confusing about that, and then give it a try with CH341A. Thanks a lot again for your help, will report back when I found something, or succeeded to access the EC’s flash.

You’re welcome! I agree it’s confusing, and best to use that guide you found, since he did seem to understand it all. Did you double check your connections with the current setup you have, and then all the guide mentioned?
Does the board need plugged in while doing this (Semi-powered, but not powered-on), if yes did you do that?

However, that image you posted above, shows SPI Flash (EC Chip) And it says use keyboard method “So you don’t have to take machine fully apart”
That leads me to believe on one side of the motherboard or the other you will find the EC SPI BIOS Chip (Probably looks the same as BIOS chips SOIC8, possibly 150mm instead of 200mm)
Just a guess, based on reading that image above again.

The motherboard was powered from it’s own adapter while I did it.

Here are some pictures of mb and datasheet:

IMG_20181213_113016.jpg



IMG_20181213_113241.jpg



spi1.png



spi2.png



So the flash chip should be at UE4, for ENE KB930.

But no problem. I have found this in KB9012’s datasheet:

spi3.png



spi4.png



If my understanding was good, the XBI part of it is redirecting SPI related commands to external chip, for “non-E-Flash KBC”, so KB930. And maybe redirecting to internal flash chip for KB9012.

One thing that maybe caused the chip wasn’t detected. I just grounded pin 42 (TP_PLL_Lock), as in the guide, but not pin 41 (TP_TMUX), which is in datasheet where it says “Please note while TP_TMUX and TP_PLL_Lock keep low at the same time, a mechanism called FlashDirectAccess will enable”.

ENE KKBC is the keyboard controller, this is what allows you to flash through to the SPI. The SPI Rom 128KB image is of a SOIC BIOS chip as I mentioned.

There’s no no chip at UE4, did you dump all three SOIC8 chips and see what’s what? Looks like third one there under ENE chip, under 940 label, right at O or Q27

Yes, maybe you need to ground both of those for the lock to enable?

I googled for all SOIC8 chips on the motherboard, they are MOSFETs or voltage regulators except W25Q32BV and EN25QH16.

IMG_20181213_152348.jpg



IMG_20181213_152530.jpg



IMG_20181213_153146.jpg

Thanks, yes you are correct, now that I can see it, that one I mentioned is not a BIOS/SPI chip!

Send me dump from both BIOS chips you showed in image two on post #13, maybe EC is stored within one of those in a BIOS region. This is common with Dell/HP, one chip is part or all of BIOS, and other is part of BIOS (or not) + EC, FD, ME
Label them in a manner so that you know which is which, in case I find EC and can update one of them for you to program back. *Edit, wait, I guess this wont help right now, since they were blanked and re-written by you already, so we have no way to confirm if EC was originally in one of them or not.
So never mind that thought And, anyway, looking through all the dumps I have, none of them have EC contained within those two chips anyway, always a separate file and same as in the stock exe image EC was separate from the other two images, shouldn’t be typing and sleeping I suppose

I will do it somehow, just need to reach the EC’s internal flash through the debug mode. Maybe with pin 41, maybe with connecting SPI first and then laptop’s adapter, or with CH341A… I google more about that, hope someone had similar problem.

Maybe you just need to ground both those connections you mentioned instead of one, then your original method attempt will work.

Hi @Lost_N_BIOS !

Today I have flashed the files you sent, the laptop is working without problems. Thanks a lot! :slight_smile:

@UDPSendToFailed - thanks for update. Do you mean files from post #4? If yes, thanks for confirmation all is working OK. Did you end up having to use the EC file too

Yes, the files from post #4. As I thought, the problem was with EC’s embedded firmware, so reflashed it with CH341A, and the laptop returned to life.

Good to know that EC is confirmed working too, thanks!

This will be a bit off-topic, but maybe you have idea… I’m trying to unlock Advanced and Power tabs with help of donovan6000’s guide: https://web.archive.org/web/201510091027…power-tabs.html

Found all 9 tab’s offsets, compared with EFI IFR dump they are at the same location, but every tab has two DF424DB5523951 values except the first tab(?), and it’s not listed in IFR dump:

bios1.png


bios2.png



That’s a bit weird, but let’s go to next step, search for tab calling function, here is the problem:

bios3.png


bios4.png


bios6.png



Okay, looks like this is the calling function with all tab’s location referenced, and some other values. What to do now? There are no conditional jumps which donovan6000’s guide talking about. All the 9 “normal” tabs having only this calling function, except the first unknown one:

bios5.png



Here are the currently available tabs:

IMG_20190219_141625.jpg

@UDPSendToFailed - First tab, be it main (sometimes two main’s) or hidden setup that’s not used as an actual tab, can often be unnamed or different than the rest like you mentioned

This is a tough one! I tried to figure it out that way, doesn’t look like that method can be used on this BIOS. I checked mainly about one hidden tab Advanced, any area it’s referenced or used does not contain any jumps or bypasses going around it, very tricky!
I considered changing variables for suppress if, but checked advanced menu and it’s not even suppressed in the IFR, so not sure where to go next

Well not a big problem, anyway thanks for checking it. I can access all settings through EFI Shell. The only problem is the HDD in optibay. When I restart the laptop, it makes an ugly clicking noise, like when the power is cut from it, and then immediately starts to spin up again. I don’t know if this is hardware or BIOS-related problem, the HDD caddy worked fine in my backup laptop without cutting power from HDD on restart.

@UDPSendToFailed - sounds like spinup, and it’s disabled on all ports in the BIOS. Maybe the HDD is failing? Or maybe it’s the CD/DVD instead, have you removed this to see if that’s the source of the sound?
Swap in another HDD for test, then you’ll know if it’s always happening, or only with that drive in there now. Hard drives only click when dying, this is commonly called the “Click of death”, so if you test another drive and it doesn’t do it, backup this one quick as you can because it’s possibly dying soon.

Yes, I have tried the spinup setting in BIOS, nothing changed. The HDD is fully okay according to it’s SMART:

hdd.png



There is no DVD drive in the laptop, only moving parts are fan and HDD in it. The SSD is in HDD slot, and the HDD is in place of DVD drive, in a caddy like this:

s-l1000.jpg



I have swapped them, so SSD in caddy and HDD in motherboard’s slot, it didn’t click on restart, but the SSD’s Unexpected Power Loss Count SMART value has increased by 1 on every reboot. Sadly the DVD drive slot on the laptop is SATA2, the SSD was limited to ~270MB/s, so I have reverted to old setup. That clicking sound is exactly the same as when I force shutdown the laptop with pressing power button for 4 seconds, and only happens on restarts, not under normal use.

But I can live with this problem, I don’t restart the laptop too often, so possibly it will not kill the HDD.

So, sounds like the original slot (CD/DVD) is setup to cut power on soft reboot, but main HDD slot does not do this and retains power. I am not sure how, or if it’s even possible to change a setting for that
I don’t think it will hurt the drive, especially if you are not rebooting often, since this would be normal situation when shutting down or powering up anyway.
It may also be some surge, you know how CD/DVD spins up when starting, so could be related to that, maybe we could change that setting somehow, or mark that slots usage as not CD/DVD.
I will look and see if I can find anything like that. Have you already, or can you, remove this slot/drive from the bootup/startup list in the BIOS? Not move to end, but remove from listings

* I can’t find anything like I mentioned, but I did see hotplug enable/disable, did you tinker with those, maybe that would help if you enable this for that slot?
Same for “SATA Device Type”, did you try changing this to SSD for the slot instead of HDD? I know that doesn’t make sense, but something to test.