Hyper-threading disable i5 480m caused bios brick

Hello
I have Acer Aspire 5742 with i5 480m processor and 540m GT nvidia card, yesterday I did terrible mistake changed Bios setting and turned off HT it killed my laptop black screen fan working and laptop turns off after 30s or so. Now I dont know if I killed my CPU or bios needs reseting, tried flashing Bios with recovery mode holding FN+ESC keys, no luck.
tried searching for CMOS battery cant find it, in manual it show's that battery is located under Wi-fi network card, BUT ITS NOT THERE i only found something wich looks like battery but its no so easy to remove.
http://i.ebayimg.com/t/NEW-Acer-Aspire-5315-5515-Cmos-RTC-Bios-Battery-GENUINE-/00/$(KGrHqQOKjQE3!8PIKjpBN6Smk1+JQ~~_35.JPG
Before taking any futher action IM going to ask for advice ?
If I cant get this laptop working again I might as well sell it peace by peace.
Warrenty is already over ;(

 

It is a CMOS battery on the photo attached. You should remove it and leave the laptop like that for while or find proper points on the mobo and short them to reset CMOS.
To to the latter please consult a service manual (see the sticky for service manuals).

Nothing is damaged- you just need to reset all settings by removing CMOS battery.

 

removing this battery requeres soldering, and I dont have tools for it so I guess Il just take it to repair service to reset bios. I thought my cpu is damaged because then I try fn+esc recovery power button doesnt flash like it should I read in other forum that it means hardware problem.

 

No it doesn't- not in this case. Unfortunately for you in this case BIOS recovery wouldn't even work sine your mobo doesn't even have a functioning CPU.

 

Once I disabled HT in BIOS and flashed it. It bricked my BIOS too. VAIO F12 I7-740QM. I had to reprogram flash with the correct BIOS. You need to unsolder it, back up data from it, replace in HEX editor some BIOS parts and solder it back. It took 6-7 times for success in my case and HOURS AND HOURS for compile proper bios image. Now I can do it faster of course.

 

its hard to beleave that HT disable could kill cpu, so il keep my fingers crossed that unsoldering CMOS battery will help. If not il have to buy new cpu I wonder how much i7 quad core costs for a laptop

 

I agree that a HT adjustment in BIOS could not do what is being said but I don't really know. I do doubt you damaged anything beyond repair.

 

james d gave me hope, reparing this should not cost much

 

BTW changing CPU will NOT help at all. Your BIOS is bricked not CPU. I upgraded my CPU up to 840QM while laptop was dead. But do not do this with different architecture CPUs like Arrandale Dual Core which you have and Clarkdale Qaud I7 which I had. Even though they are 1-st gen. BTW 1-st gen I-core cost not much at all.

You need to find good repair SC or at least someone who can unsolder bios chip and has a programmator. I can help you with compiling bios. No promise though.

 

done my laptop is at repair service

 

Hello James. I just joined this forum to ask you advice

I disabled HT on my Acer Aspire 5742G-384G50Mnkk with NEW71 LA5893-P mobo (Intel 3xxx + Nvidia GT560M discrete). The BIOS I was using was some Chinese modified/unlocked BIOS that my friend flashed on the SPI ROM before selling the device to me. And of course, disabling HT bricked the device, because either the non-modified parts of the BIOS code expect HT enabled or the CPU does not work without initializing all the cores.

I have a friend who is proficient enough to change SPI ROM chips on devices, and maybe even reflash them (he's done it before on smaller form factors). I've already ordered a compatible, pre-flashed SOIC SPI ROM from a german vendor, and our current plan is to replace the SPI ROM on the mobo with the pre-flashed one.

However, I would be interested in knowing how to reflash the current SPI ROM so that it got HT Enabled. My friend can most likely get a binary dump from the current SPI ROM (by using AVR and some hacker-magic I suppose). If you feel like it, you could give us some pointers on how to find the correct memory location (or locations) in the dump to modify. What would need to be done to find the correct locations to modify in the BIOS dump? Do we have to analyze the BIOS code in IDA Pro and look for some spesific opcode pattern that initialize the cores, then look for a condition which would skip the initialization?

Did you use a Hot Air Station to unsolder/resolder the chip or did you manage to do it with a normal soldering machine?

EDIT: My friend said that the SPI ROM uses such a high speed on the SPI link that it is impossible to solder two SPI ROMs side by side with a switch. My best bet at experimenting with BIOS mods is to order a secondary motherboard, and learn how to re-solder SPI ROMs myself. Might even try installing some SOIC holder on the second mobo so it might be possible to switch the chip without soldering. Not sure if there are any compatible SOIC holders though.

 

Hello. Did the BIOS chip replacement help is the laptop now operational?

 

Hello and sorry for late reply. In case if preflashed chip didn't work here is what you should do.
1. Get a dump file from old bricked chip. You will need to mod it to get it t work.
2. Use HEX editor and I suggest HEXWorkshop.
3. Get a rom file downloaded from notebook's support page. You may use 7zip to unzip downloaded file if it is in exe format.
4. Search in the dump the beginning of downloaded rom file. In this case you can find the beginning of BIOS region in your dump in case if downloaded rom file is smaller than dump.
5. I suggest to select in the dump file the exact size from that beginning point (which you found earlier) which matches rom file. Example: if rom file is 4MB then got to the begining point of dump and select 4MB size. Then press Ctrl+C and create new document and paste info. This is how you copy BIOS region of dump file.
6. Compare newely created bIOS region with rom file. Set in advance settings of comparison all lengthes to 1.
7. The easiest way (but it may not work) is to just replace in the dump everything which doesn't much the downloaded rom file NOT TAKING TO ACCOUNT bytes which are empty (FF) in the ROM file.