Soldering Guru's -- What am I doing wrong?

[PaperclipGod]

I bricked a mobo by flashing it with the wrong BIOS update. I've tried every software technique to recover it, but it's dead. My last option is to attempt to de-solder the chip (it's not socketed, unfortunately) and replace it with a PLCC socket for a new chip.

I'm not very skilled with a soldering iron, though, and I'm having a hell of a time. I've been practicing on some scrap PCB using a desoldering braid, but it seems to take ages to heat up the joint enough to liquefy the solder... which makes me think it's cooking the hell out of the actual IC in the process. The couple tutorials/videos I've found on the process seem to indicate that the solder should liquefy pretty quickly, but I've had no such luck.

The iron I'm using is a digital radio shack unit adjustable from ~300-850F. I've only got one tip, though -- it's about an inch long and tapers to a fine point. Could part of my problem be the tip I'm using? Even at the full 850F, it takes a while to melt solder with the end of the tip, but the base of the tip melts it quite quickly. Am I just losing too much heat with that sort of tip? Or does this unit just not get hot enough for what I'm trying to do?

Any help, tutorials, guides, advice, etc would be super appreciated!

 

[heymrdj]

What board did you have. Alot of boards bios systems have a hardware basic reflash system. This is normally a floppy disc with the appropriate BIOS and a keyboard combination via a basic PS/2 board.

 

[Blain]

Modern MB BIOS chips are removable. :roll:
How old a MB are you working with?

For others that ruin their removable BIOS chips...
Bad Flash .com offers free shipping "anywhere in the world"

 

[RebateMonger]

I can only sympathize. I've been soldering since the 1960s, and I failed at my attempt to desolder some power capacitors on a heavy-duty Dell server motherboard a couple of years ago. I'd successfully changed out capacitors on several Abit boards, though.

 

[corkyg]

Have never seen a mobo where the BIOS chip was not in a socket and pullable. It almost has to be. You sure you're looking at the right chip? Are you possibly trying to unsolder the socket instead of the chip?

 

[Jeff7]

Pic of the chip in question?
Maybe another pic of the entire motherboard, with the chip pointed out, would also help.

And what is the model# of the motherboard?

 

[PaperclipGod]

Originally posted by: heymrdj
What board did you have. Alot of boards bios systems have a hardware basic reflash system. This is normally a floppy disc with the appropriate BIOS and a keyboard combination via a basic PS/2 board.

It's an MSI K8T-Neo. The only BIOS recovery method on this board is to use the boot-block sector of the BIOS to force it to look on the floppy drive for the correct BIOS ROM. Unfortunately, that method isn't working. It looks like the boot-block was scrambled as well.

And yep, I'm sure I'm looking at the right chip.

 

[Colt45]

32 lead PLCC? http://media.digikey.com/photo...Photos/453-32-PLCC.jpg

You'll need hot air for that... You'll have a hell of a time getting a SMT socket on without it, too..
http://rocky.digikey.com/webli...0-44-020-17-400000.jpg

edit - i guess it's 32 lead PLCC for the bigger flash chips on mobos, not 28.

 

[Colt45]

This is your board? Looks socketed to me. lower right corner, between ATX connector and winbond chip.

http://www.tomshardware.pl/mot...images/msi_via_big.jpg

 

[Jeff7]

Originally posted by: Colt45
This is your board? Looks socketed to me. lower right corner, between ATX connector and winbond chip.

http://www.tomshardware.pl/mot...images/msi_via_big.jpg

Do a Google Image search, and select Large.
One of the matches there shows the BIOS chip without a socket.
Text
(Don't know if they have hotlink protection.)


It's kind of sad that after so many years, they still can't do anything better than this BIOS.
1) The features and interface are pathetic. I had a Supermicro P6SLA board, back when Pentium II's were all the rage. That BIOS had a GUI and mouse support.
2) Some kind of protection against faulty BIOS flashes.

 

[Colt45]

Well when you get down to it, there isn't really a way around it afaik... the cpu needs to get info from somewhere.

I guess they wanted to save 10 cents worth of socket on your board.. sucks

A few of the servers I've had have redundant bios chips, that's probably the best solution... you can boot on one and flash the other, so you can't brick it. Of course it would cost an extra 50 cents in parts to implement, and the percentage of people that brick their motherboards, or even flash their bios at all, is very minimal compared to the investment cost.

I seem to recall one of my non server rigs having it.. maybe get a board with dualbios next time
http://www.gigabyte.com.tw/Fil...newtech/tech_dualb.htm (old)

my current board has it too. http://www.gigabyte.com.tw/Pro...ew.aspx?ProductID=2995
But, this new board looks like it has small SOIC 8pin BIOS chips.. which means they're accessed serially. I'm quite unsure how this works, as historical x86 stuff needs to boot to a bytewide ROM, to get instructions. -- back then it was on the ISA bus, which was a direct extension of the CPU's addr/data busses. I'm pretty clueless as to how it works now days

anyways, yeah.. hot air rework. I could probably do it for you, but shipping up here and back would probably cost the same as getting a new board

 

[Googer]

Originally posted by: PaperclipGod
I bricked a mobo by flashing it with the wrong BIOS update. I've tried every software technique to recover it, but it's dead. My last option is to attempt to de-solder the chip (it's not socketed, unfortunately) and replace it with a PLCC socket for a new chip.

I'm not very skilled with a soldering iron, though, and I'm having a hell of a time. I've been practicing on some scrap PCB using a desoldering braid, but it seems to take ages to heat up the joint enough to liquefy the solder... which makes me think it's cooking the hell out of the actual IC in the process. The couple tutorials/videos I've found on the process seem to indicate that the solder should liquefy pretty quickly, but I've had no such luck.

The iron I'm using is a digital radio shack unit adjustable from ~300-850F. I've only got one tip, though -- it's about an inch long and tapers to a fine point. Could part of my problem be the tip I'm using? Even at the full 850F, it takes a while to melt solder with the end of the tip, but the base of the tip melts it quite quickly. Am I just losing too much heat with that sort of tip? Or does this unit just not get hot enough for what I'm trying to do?

Any help, tutorials, guides, advice, etc would be super appreciated!

At 800° F you are likely cooking the silicon inside of the chip. Low temperature soldering irons are best for IC use.

 

[RebateMonger]

Originally posted by: corkyg
Have never seen a mobo where the BIOS chip was not in a socket and pullable. It almost has to be. You sure you're looking at the right chip? Are you possibly trying to unsolder the socket instead of the chip?

Although I don't really pay attention to such things nowadays, I'm pretty sure you could find modern motherboards with non-socketed BIOS chips. Certainly laptops. And likely some lower-end boards. But, no, I couldn't name any examples.

 

[rarebear]

I would use a flat tip to add more heat..

A really big problem with the gun type units is the two chrome rods sticking out from plastic handle do not transfer heat well to copper tips and you have to tighten lock nuts to where you think they are about to strip so tip heats up to correct temps..

I bet your tip is not tight, get some pliers and lock it down and try it on medium.......

 

[tcsenter]

Originally posted by: RebateMonger
Although I don't really pay attention to such things nowadays, I'm pretty sure you could find modern motherboards with non-socketed BIOS chips. Certainly laptops. And likely some lower-end boards. But, no, I couldn't name any examples.

Its actually more common now than ever, due to the newer flash interfaces and ICs being used. Here is Gigabyte's newest Dual BIOS, no socketed chips:

GIGABYTE GA-EP45-UD3LR Intel P45 (two small IC next to CMOS battery labeled M_BIOS and B_BIOS)

MSI boards without socketed BIOS IC are easy to spot because the AMI or AWARD BIOS sticker that is a perfect fit for the top of PLCC BIOS chips are too large for the new 8-pin serial flash SMT chips, so they just stick it on an unpopulated area of the PCB somewhere:

MSI P35 Neo-F Intel P35

MSI P45 Neo3-FR Intel P45

Most of Intel's recent boards have soldered BIOS IC. e.g. DG33FB, DG35EC, DP35DPM, DG43NB, DP45SG, and others. I could find a couple dozen more but I'm too lazy.

 

[PaperclipGod]

I dug out my heat gun and practiced pulling off a 32 pin PLCC socket + chip from an ancient video card (ATI Rage). I was worried about heat screwing the chip up and/or melting the plastic socket, so I heated the PCB from the reverse side. The actual tracings and pads melted before the soldered pin connections did... lol. I did get it off in one piece, though, and I was able to clean up all the pins with the desoldering wick. I also practiced removing a couple other IC's with the soldering gun, and it's HARD to do without overheating the IC or heating up the other parts of the board.

I'm gonna go ahead and try to solder the socket to the bricked mobo, today... wish me luck!

 

[Modelworks]

In the future if you want to remove multiple pin devices easily buy some http://www.chipquikinc.com/new...s/cq_new_june_2004.htm
Chipquik is the easiest way for a home user to remove chips.


To replace chips use solder paste and hot air gun.
http://webtronics.stores.yahoo.net/noclsopas29.html

Most of the newer boards do not provide sockets for chips because they are not using the old eeprom chips anymore. They are using the newer spi flash chips. The reason is because they only require 5 pins to interface. I have removed them from boards , flashed them and soldered them back on the boards. You only need a parallel port and a buffer ic to flash these chips. They cannot be flashed while on the board though, so there is no using test clips.

 

[Modelworks]

Originally posted by: Colt45

But, this new board looks like it has small SOIC 8pin BIOS chips.. which means they're accessed serially. I'm quite unsure how this works, as historical x86 stuff needs to boot to a bytewide ROM, to get instructions. -- back then it was on the ISA bus, which was a direct extension of the CPU's addr/data busses. I'm pretty clueless as to how it works now days

The newer bios chips connect to the southbridge that has an interface called SPI. It is a pretty simple but powerful way to address chips. In a lot of ways it is similar to USB. It has a data, clock, enable , reset pins that are used. You pull the enable pin high, then send a data stream that is in sync with the clock. Then send the data with address bits first for that specific IC, then follow with the data to be programmed. You can have up to 128 devices on the same 4/5 wires so that is why the address is sent first.

http://en.wikipedia.org/wiki/S...ripheral_Interface_Bus

A very simple programmer I use to program bios chips can be built for about $5.
http://www.retroleum.co.uk/spilep.html