Remove 130XE RAM Using Rework station?

[bbking67]

One of my 130XE computers is dead (fails memory test). UIt's a 16-chipper and most of the chips are Micron 4264's (oddly the first one is a TMS 4164).

 

I can probably remove the chips if I'm lucky and careful using an iron and a solder sucker, but one of my colleagues suggested using the following "rework station":

 

eBay Auction -- Item Number: 290547476926

 

The idea is to use hot air to flow the solder and remove the chips. My colleague's claim is that this is less likely to damage traces on the PCB and that this method is essential for surface mount in other applications.

 

I'm thinking of buying this kit (need a better iron anyway). What do you guys think?

[Rybags]

The soldering is thru-hole rather than only on the surface so it mightn't heat the solder sufficiently. And any stray hot air could easily damage the traces.

 

With an iron you desolder by simply applying to the pins one at a time, close to the board but not touching from the component side, then use a pump to suck from the other side.

 

I did this successfully for a number of Pokey chips on 7800 carts and also to recover some 64k x 4 chips from an old graphics card to use in 600XLs.

 

 

The trick with this method is to not snip the pins first (allowing undamaged recovery of chips), and to not do adjacent pins consecutively - move around the board so that heat doesn't build up too much in one area.

 

In some cases the GND and power pins will have thicker traces which tend to carry away the heat making the job harder. The trick there is to leave for last and simultaneously heat the pin while levering the chip upwards. Then it's usually a simple job to get the excess solder out later.

[candle]

bad idea

board won't withstand prolonged exposure to hot air - best would be to use desoldering station and then rework station to melt any solder left and help chips to let go of the board

 

ps. i know this for sure - learn from mine experience - it WILL delaminate

[+Larry]

I recently bought a Hakko 808 desoldering gun. Basic principle is the same as the unit Candle mentions. The Hakko makes desoldering a breeze.

Here's a link from Amazon, but these are widely available. You can find videos posted on Youtube of using these desoldering guns.

 

http://www.amazon.co...24674310&sr=8-1

 

Note that this is a desolderer only. You still need a good soldering iron such as the Hakko 888 soldering station, but there are quite a few to choose from.

 

If cost is an issue, the best low cost type that I've used is the "plunger" type desoldering iron:

http://www.amazon.co...4674736&sr=1-17

 

Doesn't require "three hands" and does a decent job.

 

BTW, everyone has their own favorites. And with any device, the technique is as important as the tool.

 

-Larry

[+remowilliams]

best would be to use desoldering station and then rework station to melt any solder left and help chips to let go of the board

 

Yes, that's what I've done with my Aoyue. At least when I cared about the board, otherwise I can heatgun the chips off.

[+bf2k+]

Since they are Micron RAMs, I would not care about destroying them, so I'd cut the bodies off of them and desolder the pins separately.

[sloopy]

bad idea

board won't withstand prolonged exposure to hot air - best would be to use desoldering station and then rework station to melt any solder left and help chips to let go of the board

 

ps. i know this for sure - learn from mine experience - it WILL delaminate

 

I would agree with this, I have the Aoyue 701A+, which is the desolder/solder station in one, and have done alot of XE boards with no problems...

 

as for the Hakko desoldering gun, my only issue with it is weight. When you are doing alot of desoldering, even something 1lb can get heavy after a while...

 

sloopy.

[+Stephen]

Score! My folks got me the Hakko 808 for Christmas - can't wait to try it out.

[+Larry]

You must have been very good in 2011!

You're going to love it!

-Larry

 

Score! My folks got me the Hakko 808 for Christmas - can't wait to try it out.