HP Pavilion Gaming Laptop 15-ec2523nd - Dimm2 slot disabled after corrupt bios repair? Advice requested.

[Bloodhoundje]

Hi everyone,

I have been doing hardware repair as a hobby for some years now and recently decided to learn about repairing laptops as a fun challenge.

I managed to get my hands on a "HP Pavilion Gaming 15-ec2523nd" notebook that only shows a white power LED and doesnt respond to anything.

After initial testing I concluded the bios seems to be corrupted since all voltages are normal and there are no shorts. HP has a feature for a bios restore from USB with winkey+B for this model. This did not work.

I have desoldered the bios chip (GigaDevice 25lq128csig) and managed to make a dump of the corrupted bios (using a CH341A).
So far all has been going accoording to my expectations but I am now running into an issue of which I am not sure of if this is caused by the bios I am using.

I downloaded the latest bios binary from the HP site for the laptop. I succesfully wrote this to the bios chip and managed to get the laptop to fully boot with the "factory programming mode enabled".

The new bios was missing all the laptop identifiers so I have manually added those with the "BIOS Configuration Utility", this is the DMI editing for HP as I understand. I managed to check the values I added by searching for them in the old bios binary file.

So far all seemed to work fine. Except that the laptop only uses the 4GB ram in the dimm1 slot. There is 2x 4GB ram in this laptop and swapping the modules around does not fix the issue.
When running Aida64 I can see both ram modules are recognized (it shows modules with both their unique serial numbers). Only for an unknown reason the bios is ignoring dimm2 and windows can only access dimm1.

My asssumption is that the bios is missing a flag that enables dimm2, however I am not certain about this since I do not know the history of this laptop and if this issue was there allready before the original bios was corrupted.

Attached in the ZIP file I have the corrupted original bios binary, the new HP bios binary and the config.txt which I use to alter the HP bios with DMI information (Feature Byte, build id etc). The HP DATA txt file contains the information I managed to grab from the HP parts site and matches the old bios on identification information.

I have tried searching through both binaries with ImHex but I am not sure which flag would be used for defining what memory slots are enabled/available.
Would love to hear if there is anything I am overseeing and if there is any additional steps I am missing to get dimm2 to be enabled again. So far I checked the bios guides and searched the forum for any insight into this issue without luck. Also if there is any information missing please let me know and I will do my best to obtain this as speedy as I can :-)



Laptop information: HP Pavilion Gaming Laptop 15-ec2523nd

Feature Byte: 3K6b7K7WaBapaqasawbFbhcbdUdpdqfPfdhZm9.qd
Build ID: 20WWDU1T604#SABH#DABH
Serial Number: 5CD129BLB0
Product Name: 15-ec2523nd
UUID: 354344313239424C42301AE67705AAE0
Product Number: 461U2EA
MAC Address: 1AE67705AAE0
System Board CT Number: PLFTQ028JFG2AF
System Board ID: 88DD

Thank you in advance for your time and patience :-).
Sincerely,
Rogier

[peste]

try to write it again and see what happens... use one of these programs..

https://www.badcaps.net/forum/showpo...6&postcount=10
https://www.badcaps.net/forum/showpo...postcount=7

[Bloodhoundje]

AsProgrammer didnt give my any luck, with Neoprogrammer there was some change, After entering Bios i did see 8gb memory listed, however the bios froze, upon reboot I received the corrupted bios message from HP and automatic bios recovery started. After the automated recovery completed the bios listed 4GB again and vendor programming mode was unlocked again. I have new Bios chips on order, will see what happens when I program a new IC instead of the current one. At least it does seem that the issue is bios related and the dimm2 socket is not the issue. I will update once I have the new IC programmed and running.

[Bloodhoundje]

Update, I have received the new IC's and reflashed the bios with great succes this time. Dimm2 is recognized and working properly now and the laptop is back in fully working conditions! Thank you for pointing me to Neoprogrammer, this seems to be the most stable software I have found so far for reprogramming the IC.