HP 8570w BIOS Chip de-/resolder

[KingZer0]

Hey guys,

i got a HP Elitebook 8570w on my hands, which needs a bios chip replacement.
Unfortunately my soldering experience is kinda novice level, so i thought the best first step would be to get informations of how to do it right and ... well, here i am

First of all, here is a picture which shows the chip i have to replace.

Link

I guess my first, most basic question is, if you would recommend doing this with a hot-air station or by just using a regular soldering iron.
The hot-air station approach seems less error-prune but i am not sure if i would desolder anything, surrounding the bios chip while trying to heat it up.

Thank you guys in advance for all your helpful replies.

[RethoricalCheese]

Re: HP 8570w BIOS Chip de-/resolder

I am using a soic-16 clip there.
But I don't see any issues with de-soldering with hot air there. Just do it
Remove the RAM to get some room.

[KingZer0]

Re: HP 8570w BIOS Chip de-/resolder

First of all thank you for your reply.
Well lets say i do it with hot air, can i resolder the new chip with hot air as well?
So i would basically remove the chip with hot air, maybe braid the contacts afterwards (or maybe thats not even neccessary?) apply a little bit of flux to the pads, position the new chip carefully and holding it in place with a tweezer or seomthing and then apply heat with a hot air station once again.

Or is it even possible to just remove the old chip with hot air and soldering the new immediately afterwards without re-applying new solder or cleaning the pads?

Thanks

[RethoricalCheese]

Re: HP 8570w BIOS Chip de-/resolder

Just add a bit of flux when soldering in a new chip. Might help a bit. I dont even do that. No need to clean pads.

Or if you want, you can clean pads and then solder pins using soldering iron.

But why do you replace it? If you want to remove password or fix faulty bios, always dump original bios and work with that.

[Conste]

Re: HP 8570w BIOS Chip de-/resolder

Hi there,

I always take liquid flux (mixture of isopropanol and rosin) and spread it over the contacts of the chip. Then I warm up the area and lift the chip with tweezers.

To solder, I heat the pads on the board until the solder is liquid and then just put the chip on it and let it cool down.

Work with a hot air station for just under € 100. Works very well, I am sure I already have over 100 chips in and out.

[KingZer0]

Re: HP 8570w BIOS Chip de-/resolder

Allright, i bought myself a hot-air station and some flux. Lets hope for the best. ;D
At what temperature should i start trying to desolder the BIOS chip?
Would 250°C as a starting point suffice or start lower/higher from the get go?

Thank you guys.

[RethoricalCheese]

Re: HP 8570w BIOS Chip de-/resolder

Depending on your station, I would say 350-400 and max airflow. On that model, there should be no risks with overheating.

[KingZer0]

Re: HP 8570w BIOS Chip de-/resolder

Its this one:
https://tinyurl.com/rzf7fo4

Dont`t get me wrong i have not much clue about this but 350°C - 400°C sounds like a lot when the melting temperature of the solder should be much lower, am i wrong here?
Thanks.

[RethoricalCheese]

Re: HP 8570w BIOS Chip de-/resolder

Yes, it is much lower but the heat will be dissipated So you cant get it up to temperature when using 250. Or it will take alot of time.

[Conste]

Re: HP 8570w BIOS Chip de-/resolder

I always use around 400-500°C, in my opinion the temperature is not that important...

I am using this station:

https://toolboom.com/en/hot-air-rewo...on-quick-2008/

[jasko_jacker]

Re: HP 8570w BIOS Chip de-/resolder

It depends on where the chip is positioned, using a hot air station does not create any particular problems as these chips also resist well to many solders processes. If the chip is placed near electrolytic capacitors, plastics or any component that can be damaged by heat, it is recommended to remove it only with the soldering iron; there are various techniques, some use a tip wide enough to disconnect one side at a time or a double tip to remove the chip at the same time, without this type of tips you can cover all the the pins with a sufficent amount of alloy which allows you to slightly raise one side, after two or three passes per side the chip is removed. . If you want to use a hot air station, put it to the maximum, mask the neighboring components well, and with a nozzle from a centimeter place it at about two or three centimeters, leaving it not in the same position. Simultaneously use tweezers to remove the chip as soon as the alloy for each pin has melted. However, since this type of chip is rarely damaged, the best solution is to use special clamps.

[KingZer0]

Re: HP 8570w BIOS Chip de-/resolder

Thanks for all your helpful advices.
I tried it with my cheap ass hot air station and it kinda went ok, but i had to get very close and put the heat up pretty high (400-450°C) to achieve results.
I didn`t feel comfortable with it but i hope i didn`t destroy anything due to the high temperature. The surrounding parts were covered with kapton tape but it got a little bit burned while removing the chip.
Let me show you a picture of how it looks after the bios chip removal.

Original: https://ibb.co/jGhr2bz
Zoom: https://ibb.co/tJcjY2f

From what you can (hopefully) see on the pictures. Do i have to remove the remaining solder from the solder joints before i try to resolder the new bios chip or can i just allign it correctly and solder it onto the board with my hot air station or maybe a soldering iron?

Thank you guys.

[RethoricalCheese]

Re: HP 8570w BIOS Chip de-/resolder

If you don't want to use hot air, clean up the pads and then solder with soldering iron.

If you want to use hot air, either just add flux or add new solder. No need to remove old solder.

[ktmmotocross]

Re: HP 8570w BIOS Chip de-/resolder

if u have cheap hot air dont bother with temp because it is not accurate.
board look fine. tin iron with leaded solder and tin pads with it, so when using hot air u need lower temp to solder chip back

[KingZer0]

Re: HP 8570w BIOS Chip de-/resolder

@ktmmotocross
Thanks for clarifying that up.

@all
I would like to do it with a proper soldering iron but i have yet to buy one.
I am looking around Amazon and there is a lot of cheap soldering stations or a few more expensive ones. Of course i am hesitant to buy a station that is more on the expensive side of things, cause that would easily make the whole reapiring attempt rather pointless at least from a financial standpoint. I probably won`t use a soldering station very often anyways but if a better one gives me (as a soldering beginner) a higher chance of success i would of course consider it.

I ve found a few ones that catched my eye, cheap ones and more expensive ones, maybe you guys can give me your opinion of what i should pick.
I will clean the pads on the pictures with copper braid ass soon as i have decided which soldering station / soldering pen to buy.

- https://amzn.to/2GqvATb
A cheap soldering statio with inclusing a few tips, maybe good enough to get the job done?

- https://amzn.to/2uymDok
Soldering iron instead of going for a station.

- https://amzn.to/3aKR0bG
More or less my favorite but maybe i am spending to much for a soldering job that can be just as easy done with a cheaper iron?

What tip should i go for to solder the bios chip back onto the pcb?
Thank you again for all your helpful answers.

[petehall347]

Re: HP 8570w BIOS Chip de-/resolder

i find it good to use isopropanol to clean the board after removing solder from pads .

[KingZer0]

Re: HP 8570w BIOS Chip de-/resolder

@pete

Yes, i already did that to clean up remaining flux on therr pcb when i remoived the bios chip and i will surely do that again after i cleaned up the pads

[Conste]

Re: HP 8570w BIOS Chip de-/resolder

@ktmmotocross
Thanks for clarifying that up.

@all
I would like to do it with a proper soldering iron but i have yet to buy one.
I am looking around Amazon and there is a lot of cheap soldering stations or a few more expensive ones. Of course i am hesitant to buy a station that is more on the expensive side of things, cause that would easily make the whole reapiring attempt rather pointless at least from a financial standpoint. I probably won`t use a soldering station very often anyways but if a better one gives me (as a soldering beginner) a higher chance of success i would of course consider it.

I ve found a few ones that catched my eye, cheap ones and more expensive ones, maybe you guys can give me your opinion of what i should pick.
I will clean the pads on the pictures with copper braid ass soon as i have decided which soldering station / soldering pen to buy.

- https://amzn.to/2GqvATb
A cheap soldering statio with inclusing a few tips, maybe good enough to get the job done?

- https://amzn.to/2uymDok
Soldering iron instead of going for a station.

- https://amzn.to/3aKR0bG
More or less my favorite but maybe i am spending to much for a soldering job that can be just as easy done with a cheaper iron?

What tip should i go for to solder the bios chip back onto the pcb?
Thank you again for all your helpful answers.

I have had exactly this soldering station like the first amazon listing and wasn't too happy with it. I sold it and bought an ELSA unit for 3x the price.

[KingZer0]

Re: HP 8570w BIOS Chip de-/resolder

I bought the Quick 3104 but i gotta be honest here.
I tried to remove the remainning solder with copper braid (put some flux on the pads before) but i totally fucked it uo, the copper braid was glued to the solder pads and when i removed it .... yes you probably can guess it, the solder pads came off with it.

I guess we can therefor all agree that my first soldering attempt was a huge success.
I tried but maybe i should have practiced a little more before trying what i did.
Anyways, thank you guys for all your help.

[SMDFlea]

Re: HP 8570w BIOS Chip de-/resolder

Everyone here has damaged a pad at some point,don`t worry the pads can be repaired. Time for your next challenge .