How do I find the location of a BIOS chip?

[techyguy717]

Verified a corrupted BIOS on HP Pavilion dv7-3063cl.

The BIOS chip is only 8 pins and my soldering skills are decent enough to perform this replacement.

How do I find where the chip is?

The problem is, that it looks like this.
http://www.bios-service-center.com/popup_image.php?pID=18374

Many chips on the motherboard look like that.

I've searched the internet and found nothing.

 

[NYJimbo]

Unless you know the schematic you will have to hunt it down. Since yours is a popular model you can often find out what the chip maker and ID is by googling around. I do lots of BIOS replacements and after a bit of googling and ebay searches I can usually figure out the form or package and then its just looking for a flash chip or chips and you got it.

The chip is likely a SOP8 or SOIC8, which is just the package format and it can be just about anything they can fit inside it so its all about what is printed on the chip. It isnt really that hard to remove if you know the tricks. Go to youtube and search for SMD or SOP or BIOS chip replacement.

 

[techyguy717]

Thanks Jimbo. I still do have a problem locating the chip.

Many chips look like this BIOS chip.

All the pictures I find of it has:
- no ID number
- a dot that ID's position

Could it be that the BIOS chip will be the only chip that:
1) had no ID #
2) no ID number
3) a dot that ID's position

 

[KompuKare]

While I don't do soldering work, I have made and soldered a serial lead to read one of those Atmel 8-pin chips on a Thinkpad X41 to recover the supervisor password, as detailed in here:

http://www.thinkwiki.org/wiki/Maintenance#Recovering_BIOS_passwords.

Now that was for reading the contennts, but surely re-programming the chip without desoldering the whole thing should be possible too if you can find the datasheet. For instance that Atmel is specified here:

http://www.atmel.com/Images/doc3256.pdf

There was a thread here about that BIOS rootkit (http://www.technibble.com/forums/showthread.php?t=30719), and I though someone mentioned having to reflash a whole bunch of BIOS (with an EEPROM writer) when CIH or a similar earlier virus was making the rounds. Can't find that post atm though.

Anyway, point being if it is possible to program the BIOS without desoldering it. In fact, for reading those Thinkpad passwords there was a tutorial about using a clip like this:

Of course only worth it if you're doing a more than bad BIOS.

 

[NYJimbo]

but surely re-programming the chip without desoldering the whole thing should be possible too

You would need a clip, the wires, and a programmer. That would be providing there is nothing wrong with the chip itself and that there is no interference from the board while it is in circuit. That's at least $100 in parts plus learning to use the programming software.

If someone is just going to do one BIOS I would suggest first practice removing a few SOIC8/SOP8 chips from a dead board and if you can do it without damaging the pads or traces, then buy the preprogrammed chip on ebay and solder it in yourself.

 

[KompuKare]

All very true. The only way that would pay is if you get a lot (like site where some virus wiped 100s of machines) or someone who specialises doing this on ebay. When I wiped that Thinkpad password I did consider selling that service on ebay but only for a few seconds since 99% of those would be dodgy / stolen and I don't want to go there.

Oh, and the last sentence on my original post should of course have read:

'Of course it's only worth it if you're doing more than onebad BIOS.'

 

[techyguy717]

Thanks for the reply's. But could anyone answer the last statement, here?
NOTE: By the way this is the second time I have reset the BIOS, by removing the battery, in less than a year. The first time it worked for 8 months, this time it didn't help. So, yea, it's a bad BIOS chip.

I still do have a problem locating the chip.

Many chips look like this BIOS chip.

All the pictures I find of it has:
- no ID number
- a dot that ID's position

Could it be that the BIOS chip will be the only chip that:
1) had no ID #
2) a dot that shows position
http://www.bios-service-center.com/popup_image.php?pID=18374

 

[techyguy717]

By the way, I want to make sure I can locate the chip before ordering. The customer is waiting for a phone call.

 

[NYJimbo]

Its most likely going to be a Macronix 8 pin SOP. It will "probably" be marked with a MX followed by 25L800xxxx where the x's at the end can vary. Once you find a chip like that you can google its full number and it will likely be a flash memory chip. I think most of the DV7's used the same package size and so far they have been Macronix chips, but you can also go on ebay and ask sellers to help you. I dont want to get into this as it can be A LOT of back and forth and thats what burned me out last time I was here.

 

[NYJimbo]

By the way, I want to make sure I can locate the chip before ordering. The customer is waiting for a phone call.

Not to be a smart ass but have you done any SMD removal ? PLEASE do a few small packages before you attempt to do this with a customers machine. The thing to worry about is the pads.

One other point, how did you verify it was a corrupt BIOS chip ? If resetting it last time worked but this time did not, does not mean it must be the chip. Resetting it only flushes the settings stored from the BIOS, but if you tried that again and it didnt fix whatever is wrong it doesn't mean it must be the BIOS. Just sayin......

 

[techyguy717]

Thank you. I know that I'm not looking for a blank chip. I'll Google the numbers.

The computer screen freezes with the blinking lights defining a BIOS corruption. Happened 8 months ago. Reset BIOS, upgraded BIOS.