black screen wont boot bios failure

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fagetti

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You need 4MB bios flash for that chip and latest one from HP site is 5.6mb so its incorrect size. Try to search previous versions on HP site or check your motherboard model version ( its on the motherboard when you look closely) look this http://howtofindyourpartnumber.com/toshiba-pns/ and 3rd picture there is number ending with MB-A03 its like that you find it somewhere on the mobo, then search dump file with that
 

mrbits2018

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These are the numbers on the MB. I'm searching with the product number and also on the HP site, I can't find specs of the MB. I also checked all the bios drivers and they are all bigger than 4MB.

Could it be that this is not the bios chip of the MB?

I will verify further.

thanx

 

fagetti

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If wsnu main board rev 2.1 reads there then go google and search with "wsnu main board rev 2.1"
You will find loads of sites with 4mb bios file but these sites need login / account and there can be some viruses, i dont have anymore accounts on any well known sites so you neeed to find it yourself by making account, just check for viruses.

I also still think your reading the chip wrong somehow, this little dot on chip is pin1, eventually you figure it out. I hope ec bios is not corrupted because its on another chip
 

mrbits2018

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Yes, the M board has these id " wsnu main board rev 2.1 " as you described. I made a search and I'm waiting for access approval on a web site that has a 3.9 bios file.

I think I'm placing the Soic clip the right way, the red stripe of the ribbon directly clipped on the dot of the chip aka pin one.
The only read activity that I had is one with only 0's. Placing the clip the other way output only f's and I saw a video on youtube that said the f's meant no data or no read. I'll try it again to be sure.

But you got me thinking... If the HP site drivers are bigger than this chip storage then it means that they are for the EC bios chip. The last thing I did before the M board died was trying to flash the bios with an HP site drivers. Could it be that the problem lies on a EC bios chip instead of this one?
Anyway I will download the 3.9 bios from this new site as soon I get my profile approved and also I will check again the M board for other eeprom chips.

Thank you for your help and advise.
 

fagetti

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I just assumed you have amd graphics chip since these dv4 series usually have but i was wrong and its intel cpu with hd 4000 graphics. This means its most likely bios issue, i hope we can solve this. AMD northbridge and gpu are most likely to fail on these with same symptoms but this is not the case now.

Might be that 5.6mb .fd file has other files than bios / ec bios flash. So it would need to be extracted once more and we dont have tools for that. Im pretty sure its not EC bios, if that gets corrupted you maybe not even see charger light when plugged in. Depends what part is corrupt.-
 

fagetti

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And this winbond chips is the right one, you can try programming it with 3.9 version you will download. If its succesful try to read the chip afterwarrds.

Then save the file what you programmed to bios chip and compare it to .bin file what you tried to program, there should be no differences.
Use HxD to compare the files, google it, its a free hex editor
 

mrbits2018

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How about the HP 3D drive guard loop?

When you try to power the machine the hdd light lits amber and the notebook constantly shuts and turn on again in a loop.

I have read that this MB has movement sensors and maybe this is the problem. Do you know where they are?
Is it part of the bios?

thanx
 

fagetti

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Restart loop can be also some part on your laptop shorting. So tell me one more time what symptoms it has now when you boot it? HDD light amber and caps lock light blinking at 2 time interval and black screen? When does it restart itself.
 

fagetti

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Try to boot without bios battery-

Try to start your motherboard barebone. just keep CPU and reseat and add only one ram stick, dont add keyboard or anything else, remove ethernet and wifi cards etc. Put it to your laptop back case and add power jack cable and power button cable and connect external monitor to your HDMI or VGA port. Then try to start it with power button. (remember not to short anything out when your doing this example your power button cable touching motherboard when you have power on)

- if you remove cmos battery you dont need power button cable connected at all, when you plugin power to dc jack it should start automatically without even pressing power button.

Have you tried reseating CPU? Remove heatsink carefully, unlock cpu screw and reseat it, Lock it back. Remember to clean and add new thermal paste and then add heatsink carefully back, dont put screws too tight but firmly.
 

fagetti

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if you dont have thermal paste then dont try reseating cpu, if you do it without thermal paste and heatsink you can only keep laptop on for 10second and then quickly take power cable out because you can kill your CPU by overheating it
 

mrbits2018

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Well, in the beginning it had a 2 caps lock flash, a symptom of a possible bios corruption then after flashing the bios with driver f.39 from HP site within the windows, it got into a restart loop for an hour. I got a little tense and took out the battery while restarting and when I placed it back the screen went black and with a shutdown / power on restart loop with the hdd led in amber and with one flash caps lock code indicating a possible CPU failure.

I did the procedure of reset the 3D drive guard because it seemed activated by taking out the battery as soon as turn the laptop on and placing it back again as the HP site says but it was not effective.

I also tried to turn it it on without the battery, hard drive and ram and it was the same loop. Tried also with one ram stick, placing it in different slots and got the same loop.

I also reseated the CPU and replaced the thermal paste with the same results and replaced the CMOS batter also.

I have thought of an MB short but I'm trying to fix it before buying a new MB.

thanx
 

fagetti

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So you did try booting only motherboard (on wooden table, check that there is no dirt what can cause short) with 1 ram , cpu , dc jack cable connected and external monitor vga/hdmi cable? Remove cmos battery before doing it and when you insert power to dc jack it should start automatically without power button. (some models need power button cable so if it wont then add it)

Since i never used SOIC clip and always desoldered chip when programming there could be interference when you try to read bios chip. Remove everything from motherboard even cpu , ram , cmos battery, fan connector ,network, wifi cards when you try to read bios chip. You cant have a bios chip without data, you would not even power on.

Next step is to desolder bios chip if you tried steps i said. I can guide you with it.


do you have a multimeter?
 

mrbits2018

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I dismantled the MB , completely when trying to read bios chip. I also tried to boot it without the RTC battery, drive, wify card, just the CPU and it keep shutting down an powering up. i think I also tried a VGA connection boot but no video output.

I have been trying to get the 4 MB bios file from some sites but they all ask for a paid subscription in order to download.

You are probably right about disoldering the chip but I don''t have a heatgun, is on my purchase tools list but I will soon. I have another disoldering tool but its a little bad and its tip is to wide for this small bios ic.

I saw a bios chip for this machine on ebay and its supposed to.be programmed for 20 bucks and the MB for 50.

I dont want to purchase a spare yet because this is one of my repair learnig proyects and that will be too easy.

Ill keep surfing the net for the 4MB file.

thanks
 

fagetti

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Either your doing something wrong or the motherboard is made so that you cant read bios chip without removing it from the board. You can verify this by trying to program the bin file you soon get access to, if it fails then this is the issue. If this is the case you need to either desolder chip with soldering iron, there is a technique: https://www.youtube.com/watch?v=0-kl-FVBH8I
Or cutting its legs but both have risks of damaging board if your unfamiliar with soldering iron example.
First try bios reprogram with soic

Also check all usb ports that there is no bent pins like this : https://forums.lenovo.com/t5/Lenovo-Yoga-Series-Notebooks/Yoga-2-usb-plastic-pin-broke-off/td-p/1788941



Before trying to desolder, There is small chance its processor or more likely graphics related. If there is a place you could try borrow i5-3210M processor, it has integrated hd 4000 graphics so this could solve it.

 

fagetti

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Pls dont get a heatgun, this needs some experience and dead boards to test first temperature etc. You will 90% kill the board with a heatgun.

You already have a programmer there is no need to buy preprogrammed chip, you can 100% read it off board anyway and if you buy new chip you need to replace it either way,.

Just keep searching chinese sites usually have bios dump files for free but you need to make account, same with russian sites
 
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