I can haz plan nao!

[unixronin]

As recently reported, vorlon (my Athlon64/Win2KPro gamebox and writing/accounting machine) is currently down due to a BIOS upgrade that failed in a non-recoverable manner.  I filed a tech support ticket with GigaByte, but according to their support site they haven't even read the ticket yet, much less responded to it.

So, after doing some research, I have a plan.

The BIOS on my motherboard is in 4-megabit 32-pin PLCC flash memory chips that look ... well, precisely like these, actually.  (This photo is even from a K8N board just like mine — not actually mine, because my camera won't focus close enough for macrophotography without a macro lens, and I don't own one).  GigaByte evidently decided to solder them directly in place to save the cost of sockets.

Now, it should be immediately apparent that neither desoldering nor soldering these is going to be much fun.  Except that, well, they're hosed already ... and I can buy new ones online, already programmed with an updated BIOS for my board.  That means I don't care about preserving the existing chips.

So.  I order a set of replacement flash BIOS chips (ten dollars plus shipping), and a pair of these 32-pin surface-mount PLCC sockets (fifty cents each plus shipping).  I cut the leads on the existing PLCCs, throw them away, and individually remove the left-behind leads.  Then I solder the sockets in place of the PLCCs (which I can do MUCH more easily than soldering on new PLCCs because I have direct access through the socket to the solder pads), snap the new BIOS chips into the sockets, and ... everything should be fine.  As long as I don't screw up the soldering or damage the board.

If all goes well, I'll end up with a better board, with socketed BIOS as it should have been in the first place, for a total cost to me of around $25.  Sure, it'll void the warranty on the board ... but the three-year warranty expired almost a year ago anyway, so I don't really see that as a problem.

Comments

[jhetley.livejournal.com]

And, by using sockets, you avoid cooking the new chips. Win/win.

(Me, I'm used to working with components I can *see* -- you know, like tubes and transformers and resistors.)

[unixronin.livejournal.com]

And, by using sockets, you avoid cooking the new chips. Win/win.

And much reduce the risk of zapping them, too.

[perspicuity.livejournal.com]

and you can buy the next update, and snap them in, and keep the old ones taped in a baggy "just in case"...

#

[unixronin.livejournal.com]

Indeed, there's that option too. (Or taped in an anti-static bag, more safely...)

[http://users.livejournal.com/crossfire_/]

And here I thought myself and randomdreams were the only people who still soldered anymore. :)

I'm pretty good with a soldering iron (my Dad taught me when I was 8), and I've had mixed luck getting stuff in/out of boards, particularly modern motherboards which seem extra heat-sensitive. It's probably worthwhile to get some solder wick if you don't have any hanging around, I find it works better than the suckers.

I'm interested to learn how this turns out.

[unixronin.livejournal.com]

I've used both, and generally found the wolder-sucker easier to work with on larger jobs, but braid better at getting the last remnants of old solder off. With the tiny amounts of solder on surface-mount connections, it'll probably require minimal desoldering at most anyway.

[ithildae.livejournal.com]

Be very careful about heat to the board. Modern circuit board technology deposits copper onto mylar, which is then glued to a board. Mylar will take wave soldering, but can easily melt when exposed to a high-watt point source of heat, like a soldering pencil. I have the touch about 90% of the time. It takes lots of patience to work the board without destroying it. Good luck!

[unixronin.livejournal.com]

That is a very real concern. Fortunately, I have a secret weapon.

[ithildae.livejournal.com]

Which shall, of course, remain secret?

[unixronin.livejournal.com]

Well, more of an open secret. :) My "secret weapon" is named DJ Delorie, and he fabs his own circuit boards at home and has far, far better soldering equipment than I do...

[luxobscura.livejournal.com]

So, after doing some research, I have a plan.

Okay, stop right there.

:P

[unixronin.livejournal.com]

MUAHAHAHAHA! I'LL SHOW THEM ALL!!!


(is that better?)

[luxobscura.livejournal.com]

No Plan Ever Survives First Contact With the Enemy!

[mrmeval.livejournal.com]

To solder that socket in is a bitch. Notice the plastic web in the bottom? Use small side cuts and carefully cut the plastic material at the thin points and remove the center piece. It's close to the metal don't snip that.

Keep the center piece. You can then pick the small connection pieces out because the material the socket is made from is brittle when thin.

This will allow you to get a fine soldering iron into that space and solder the surface mounted leads down. I recommend fine 2% silver solder and liquid flux.

I can do it and not get solder on the part of the pin that touches the chip. It is delicate work. Use magnification.

Clean the flux from the area with an acid brush and 90% or better alcohol. Take your time. Be careful as static will cause this to burst into flames. Use small amounts for that reason. If you have non-flammable spray flux remover, sweet, it's expensive.

Drop the piece you cut out back into the socket, stick in the chip and you're done.

[unixronin.livejournal.com]

Does the center of the base even need to be there? It's not like the bottom of the PLCC is going to touch the board, even if there was anything in either place to potentially short.

[mrmeval.livejournal.com]

It may or may not. There is one style that seems to let the chip sink down too far and may make it difficult to extract. There is another style that does not seem to have this problem. I just put that piece back in because vendors have been known to fuck with us and change the specification on a part, keep the same part number and release a supplement six months later.

If you have an adjustable hot air gun it will help. Masking tape will help protect any components near them and it will also keep them on the board. Good quality masking tape.

Oh, you *need* an extractor. If you do it wrong the socket will crack and it's trivially easy to do.

I'm not sure about the 2nd one, I've never seen one or seen it used.
The one I have a work is the first. It works well.

Spendy (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=K293-ND)
not so spendy (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=A2139-ND)

[lebo-superman.livejournal.com]

As another who knows how to solder, that not only sounds like a plan, but a workable one. Much better than having to go after a whole new motherboard (or a new unit) just to fix their crappy update problems.

Congrats on the success of your research!

[zaitcev.livejournal.com]

I've done this sort of thing before. Here's a picture:
http://people.redhat.com/zaitcev/pics/sunray_3.jpg

Unfortunately, the angle is not very good, but look at the bunch of red wires: they connect the socket to the pads on the mobo. I went this way because it otherwise requires wave soldering, as the socket overlays the pads and I cannot reach with the soldering iron.

I actually saved the chip and was able to read its contents (which was the objective of the excercise in the first place). Since I cut the wires very close to mobo's pads, the chip worked fine in the PLCC socket later and the system worked as if nothing happened.

[unixronin.livejournal.com]

That's an interesting approach. I don't think it's necessary in this case, but it's something to keep in mind. I don't know how well it would work on a surface-mount device though.

[zaitcev.livejournal.com]

Oh definitely you won't need wires, since your socket allows access to the pads. Main points are:
0. It was exactly THE SAME chip and packaging as yours.
1. At least on PCBs made in 2001 it was possible to remove the pin stubs and re-attach the wires without melting maylar, which was a concern expressed by a commenter previously. But be careful.
2. You can re-use the chips with shortened pins in such socket, if you have a programmer and can download the image from somewhere.

[unixronin.livejournal.com]

That's useful information, thanks. I don't have any plans to try to re-use the primary BIOS chip, though, because since about half a dozen successive flash attempts all failed at the same point, I strongly suspect the flash chip itself has failed.