Dell Latitude 3420 - Locating the BIOS Chip

[CapThatBrass]

Hi,

I'm trying to search for the BIOS chip on a Dell Latitude 3420 that I'm working on (faulty BIOS flash), but I'm struggling to find the exact location.

There's a Winbond 25R256JVEN chip situated on the far left side of the laptop, in close proximity to the RAM modules. I've got to heat the chip up and remove it to inspect any data stored on the chip but would rather know if this is the BIOS chip or has some other function.

Any guidance would be great.

Thanks!

[hoaca388]

Re: Dell Latitude 3420 - Locating the BIOS Chip

Hi,

I'm trying to search for the BIOS chip on a Dell Latitude 3420 that I'm working on (faulty BIOS flash), but I'm struggling to find the exact location.

There's a Winbond 25R256JVEN chip situated on the far left side of the laptop, in close proximity to the RAM modules. I've got to heat the chip up and remove it to inspect any data stored on the chip but would rather know if this is the BIOS chip or has some other function.

Any guidance would be great.

Thanks!

Winbond 25R256JVEN.
Right, that's it. It will give you 32MB of data.

[darckreign1984]

Re: Dell Latitude 3420 - Locating the BIOS Chip

Hi,

I'm trying to search for the BIOS chip on a Dell Latitude 3420 that I'm working on (faulty BIOS flash), but I'm struggling to find the exact location.

There's a Winbond 25R256JVEN chip situated on the far left side of the laptop, in close proximity to the RAM modules. I've got to heat the chip up and remove it to inspect any data stored on the chip but would rather know if this is the BIOS chip or has some other function.

Any guidance would be great.

Thanks!

Plecase Tell me how You read this bios chip?
What programmer do you use?

You desolder chip?

Any advice for wire solder pinout?

- i try to read with tl866II with chip on the motherboard, and all I obtain it's a full bin off data with 000000

[rxmvnld09]

Re: Dell Latitude 3420 - Locating the BIOS Chip

Hi,

I'm trying to search for the BIOS chip on a Dell Latitude 3420 that I'm working on (faulty BIOS flash), but I'm struggling to find the exact location.

There's a Winbond 25R256JVEN chip situated on the far left side of the laptop, in close proximity to the RAM modules. I've got to heat the chip up and remove it to inspect any data stored on the chip but would rather know if this is the BIOS chip or has some other function.

Any guidance would be great.

Thanks!

Hi, I just got a 3420 and was facing the same issue (locating the bios chip), now that I know where is it, seems like I cannot use a clamp to flash it (actually mi first time doing this), did you desolder it? And what device (?) did you use to flash it? I've seen your post and think you have a rt809f, is there something cheaper than that? I will flashing only this laptop

[CapThatBrass]

Re: Dell Latitude 3420 - Locating the BIOS Chip

Hi rxmvnld09,

Yes that's right you won't be able to use a clamp to get the data from this chip. You'll have to desolder the chip using a soldering iron or the safer option of a hot-air gun for electronics components. To be on the safe side, I'd disassemble the laptop to reveal the motherboard fully, as you'll risk melting the laptops casing otherwise.

I use a RT809F programmer - you could try a CH341A programmer but it's not worth the risk of damaging your chip - invest in a decent programmer and it pays off in the long run.

If you do decide to desolder the chip, make sure you clean the area with isopropyl alcohol and use plenty of flux when resoldering, it'll make the process much easier and less likely to over heat the chip.

Thanks!

[rxmvnld09]

Re: Dell Latitude 3420 - Locating the BIOS Chip

Hi rxmvnld09,

Yes that's right you won't be able to use a clamp to get the data from this chip. You'll have to desolder the chip using a soldering iron or the safer option of a hot-air gun for electronics components. To be on the safe side, I'd disassemble the laptop to reveal the motherboard fully, as you'll risk melting the laptops casing otherwise.

I use a RT809F programmer - you could try a CH341A programmer but it's not worth the risk of damaging your chip - invest in a decent programmer and it pays off in the long run.

If you do decide to desolder the chip, make sure you clean the area with isopropyl alcohol and use plenty of flux when resoldering, it'll make the process much easier and less likely to over heat the chip.

Thanks!

Thanks for your quick response! I have a nice tip for soldering SMD components but dont want to take the risk so I'll take the motherboard to someone for desoldering the chip with hot-air.

Once I start the process is it ok if I ask to you on this thread in case I got stuck? Cuz don't find someone else who played with this same model

[CapThatBrass]

Re: Dell Latitude 3420 - Locating the BIOS Chip

No problem, yes sure if you come into any issues just post them on this thread and I'll see what I can do, otherwise I'm sure someone else on the forum may be able to help.

Thanks!

[rxmvnld09]

Re: Dell Latitude 3420 - Locating the BIOS Chip

Hi CapThatBrass! It's me bothering again.
This week my hot air station arrived and been practicing to solder-desolder smd components in other PCBs but I can't remove the winbond chip, I placed aluminium and kapton tape to protect the near by components but it doesnt came appart apliying heat 10secs and im afraid to overheat. Any advice on that?

[CapThatBrass]

Re: Dell Latitude 3420 - Locating the BIOS Chip

Patience is key here.....

Try and keep the temperature of the hot air staton around 340-360degress (the hotter it is the more likely it'll burn the chip and melt the casing if the motherboard hasn't been removed from the outer case).

My advise would be to clean the area of the chip with isopropyl alcohol, apply some flux and heat the pins (or as near to the pads where the pins should be with it being a WSON package) with a soldering iron, with a small tip. Once fresh solder has been applied, use the hot air station around the area of the chip, making sure to spread the heat evenly. Gently push the chip with some tweezers to see if it has begun to 'float' on the surface. The hardest part is the large pad under the chip - as far as I'm aware, the pad isn't used as a grounding point, but for heat transfer (I might be completely wrong there though). It may be worth removing the motherboard and heating front underneath to help ease the solder under the chip from all directions.

Hopefully this helps a bit!

[m11ckxx]

Re: Dell Latitude 3420 - Locating the BIOS Chip

hi
can you show me a picture of the chip and where it is please, with magnifying glass and can't see it

All I can find is
Gigabyte
25R256DY1G
AJ2144
UH360
any help anyone