hey, i have a v7 and the disc does not want to spin....So i decided to change the ba chip, but i don't know hoe......can anyone tell me how to do it?
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hey, i have a v7 and the disc does not want to spin....So i decided to change the ba chip, but i don't know hoe......can anyone tell me how to do it?
Telling u how is really FAR away from actually doing it.
I will tell u how I do it with a single Iron. But if you can access a hot air soldering machine it will be a milion times easier!
My iron has a big tip (3mm) and it is 25 watt!
I use top quality solder and rework jelly.
I apply lots of jelly on the legs.
I solder all the IC's legs together forming a large single solder blob.
I place a sharp object under the IC and I gently lift it from one of its sides ( the side where the blob is). By melting the blob the ic is lifted a fraction of a mm.
Then I do the same on the other side.
By doing this a few times the IC gets lifted more than a mm!
Then I use copper braid that has lots of jelly on and I put it on the blob and put the iron on it. The solder blob melts and the braid sucks it. By removing the solder from both sides the IC becomes loose and by solely dessoldering the one or two final legs its removed!
Then the board has to be cleaned from the residues of the jelly and from any solder that is left on the pads.
New jelly should be applied on the pads and the new IC should be glued in position (the glue should keep it in place with its legs touching the pads).
Then place the board so that the leg row is positioned vertically and with the soldering iron and lots of solder, solder all the legs with a single melt! The jelly makes the solder stick only on the leg and pad and not between the legs !
Check the IC for shorts or unsoldered legs, and then clean the jelly!
BUT as I said, its different saying than doing it!!!!!
BTW for a V7 you have to remove a few of parts (fuses, capacitors...) to make space to work! Just take a picture before or keep notes to put them back correctly!
Ofcourse you must note how the BA is orientated!!
i do it the same way as gemat but use chipquik mainly http://www.howardelectronics.com/chi...tructions.html
or another method is a pin/needle and lift one pin at a time heating each pin i work on.
you can get desoldering station's made for the job from here www.antex.co.uk
EnTiTy
Entity,
In case you're planing to ditch the part you are removing, I object to the second method. The bended legs will never be straight to be resoldered again.
When I repair PS2 I cant tell when a part is fryed before actually replacing it so the part I remove may not be bad.
About the system that u suggested... Is this thing a low temp melting solder or just a different rework jelly? I red at the brosure that it makes the normal solder melt at 150C ???? is that possible??
I have never tryed removing square chips that have their legs bend to their center so far (like the ones that go to a socket too)... if this works like it says I definatelly have to aquire it!!!
i make sure the part is broken before removing you can also buy pin moulds to straighten bent pins.
it's a low temp solder and yes it does indeed make solder melt at 150c as the solder become's liquid it forms an alloy mixing solder with the compound meaning all the solder flows at 150c but only after the original solder is melted at normal temp so its yes it does after the original solder begins to flow and mix with the low temp solder it works really well.Quote:
About the system that u suggested... Is this thing a low temp melting solder or just a different rework jelly? I red at the brosure that it makes the normal solder melt at 150C ???? is that possible??
its ideal for what you describe i use it to remove mem off dead xbox mboards clean them up and replace them in working machines :) to gain 128 ram
EnTiTy
damn, thanx for all the responses......i guess i got my work cut out for me!!!!!
if you know the chip is shot, would it not be easier to clip each one of the legs off and pull out the IC. Then you can desolder each leg individually since they're not attached to the actual chip?
if you know for sure yes but the leads on the ba are pretty thick you would prolly do damage to the mb track's in the process i woudnt say clip either ther is no way you could cut each leg it would cause major damage a sharp scalpel would work tho.Quote:
Originally posted by Chinchilla
if you know the chip is shot, would it not be easier to clip each one of the legs off and pull out the IC. Then you can desolder each leg individually since they're not attached to the actual chip?
EnTiTy
You could cut the individual legs easily enough but not the center heat dispersing gnd pads.
I would also prefer to use the second method of lifting one leg at a time and then heat the center legs with a large iron alternating sides until it slides loose.
I find that doing the big glob of solder trick on each side is only safe on 8 pin chips - the more pins you have the more heat that is required and the greater chance of track and pad damage when the chip comes loose.