I took the SL that ran the first Kaloz image of OpenWRT, and attempted a RAM upgrade.

I had a 512-meg SODIMM with Samsung K4H511638C-UCB3.  This is a 512-Megabit chip and looks pin-compatible with Hynix except for maybe pin19.  Anyhow I managed to get a RAM chip off the SODIMM the first time without much problem, following the video previously posted.

I was thinking to remove the original SL RAM and replace with this one, giving a 64-megabyte SL without having to mess with 20 SMD resistors.  If that worked perhaps move on to putting on resistors and a 2nd RAM chip and see if it would go to 128 megabytes.

Next was removing RAM on SL unit. Unfortunately I used too much prying force on the chip and perhap too much heat, several solder pads came up with it.  Arrrgh! BUTCHERED it.

Let this be a warning to other soldering n00bs, easy to think you've figured it out then POOF!

*sigh*

(Last edited by vincentfox on 25 Jun 2007, 01:25)

Ugh, sorry to hear about that...  Yeah, it's easier to pull a chip when you don't care about the board you're removing it from...

Still have some hope. I'm going to order the resistors.  Then try putting a chip into the empty RAM position and see if it works.  Best case, I at least have a working router with 64 megabytes eh?  Not what I was aiming for but it would prove something and maybe salvage the situation.

(Last edited by vincentfox on 25 Jun 2007, 09:20)

Maybe you should cut off the pins of the RAM modules on the router first with a small cutting disc or stanley knife? But it's too late now...
I got a SDRAM Module via Ebay with Chips for a 64MB upgrade of my WL-500gx some time ago, and it's still lying around because I'm afraid doing it :-/

You can still save the board if the ram lines terminate at some via, you can solder very fine guage wire to replace the broken trace.

Good point.  I will investigate that. Have to find some very fine wire and try not to ruin it further.

Did you use chipquik?  I haven't had a single problem using chip quik when I used enough of it.

Here's how I do it.

1.  If there looks like there is a lot of solder on the memory, wick it up with solder wick.
2.  Put a length of chipquik down the side of the chip.  Melt it into the pins.  If that's not enough to cover the pins in one long solder blob, put down more chipquik.
3.  Melt it and let it solidify a few times.  This helps the chipquik get under the pins and mix with the regular solder.
4.  Using very light pressure from a toothpick, press upward on the ram chip.
5.  Quickly run the iron down each side of the ram chip, alternating until the chip comes up.

I haven't pulled up a single pad yet with this method.

No, I am new to soldering and self-taught.  I have not even heard of this product but I will look into it.

I just got my chipquik and have to say, it's a marvel at getting the SMD off fast and safe.
My problem is getting the new RAM chip on.
I've spent an hour trying to remove bridges and stuff but the router still doesn't boot.
Those darn pins are so small that I can't really see whats going on, even with x5 magnifying lamp.

vincentfox:  Go buy some.  It's worth every penny. 

nekmech:
Do you have a plunger type solder sucker?  I have found decent success by using ample amounts of flux, heating the solder, and releasing the plunger.  It should take off all the excess solder, leaving enough solder to connect the pin to the pad.  Make sure to position the sucker before you heat the solder.

Keep in mind, you only really need solder to be under the pin and on the pad.  Look at all the other connections on the board.  More isn't better.

I'm talking about something like this: http://www.allelectronics.com/cgi-bin/c … em=50B-410

No I hate those suckers.
Used them for a while years ago and got tired of them always getting clogged.

Maybe now that I'm older I'll have more patience.
Thanks.