Hardware A horrible question about replacing chips


squaresosig

Member
Joined
Jul 15, 2012
Messages
52
Long long ago my pandora died. The display backlight circuit broke after a fall and after fixing it the keyboard was partiall unresponsive.

A few years ago this led me to foolishly attempt to reflow the chip responsible for the keyboard (TPS65950). This did not go well.....

So my question is, now that many years have passed, my equipment is a lot better and my knowledge is too... Would replacing the TPS65950 actually work?

As far as I can tell from datasheets and schematics the chip doesnt have any internal programming, so assuming I was able to solder it on correctly it should work, but I also know that this is a LONG SHOT and that my pandora is almost certainly dead forever. Sad that it was entirely my fault, but at least the pyra will be available soonish.
IMG_20200727_015726.jpg
 

levi

Still fresh, damnit!
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Oct 6, 2008
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12,967
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Somewhere off the coast of the EU
It should work, but I wouldn't even attempt to solder a BGA chip in unless you have a good reflow station, and practice at using them. That's assuming the problem was with that chip.
 

squaresosig

Member
Joined
Jul 15, 2012
Messages
52
BIG NEWS

I was able to find some chinese resellers on eBay that sold the TI power management chip.

First attempt did not go well, and I basically just melted all the balls of the chip together. I also found that my liquid flux was woefully inadequate, evaporating immediately when heat was applied.

IMG_20200918_135244.jpg
The aftermath of that

So I did some more research, watched some videos from Louis Rossmann and purchased some of his recommended Amtech flux... and another TI chip.

The chip came today, and after cleaning the area with IPA and fluxing the hell out of it, I aligned the chip and applied heat, and went through the process of it moving from the air and realigning it about 10 times before it stayed put. The chip did solder and I could see the joints from the side, but it would not boot! no lights, no life!

IMG_20200918_135232.jpg

I decided that it hadn't worked and reflowed it again, and physically poked it down with my tweezers our of desperation. Somehow that did it!

119674720_405628567490233_6605289974357415943_n.jpg

So after many many years of my GHz Pandora being broken, its finally back to life. The last problem it had before it died completely was the keyboard not responding, and thats fixed too!

Now all i have to do is replace the left joystick, since a attempted repair years ago left it in bad shape. That shouldnt be a problem though since I have an ICP1 from the ICP2 Kickstarter... I'm looking forward to all of the systems that the CC unit I have is too slow to run!
 

Swordfish II

Advanced Member
Joined
May 20, 2015
Messages
1,052
BIG NEWS

I was able to find some chinese resellers on eBay that sold the TI power management chip.

First attempt did not go well, and I basically just melted all the balls of the chip together. I also found that my liquid flux was woefully inadequate, evaporating immediately when heat was applied.

View attachment 36505
The aftermath of that

So I did some more research, watched some videos from Louis Rossmann and purchased some of his recommended Amtech flux... and another TI chip.

The chip came today, and after cleaning the area with IPA and fluxing the hell out of it, I aligned the chip and applied heat, and went through the process of it moving from the air and realigning it about 10 times before it stayed put. The chip did solder and I could see the joints from the side, but it would not boot! no lights, no life!

View attachment 36506

I decided that it hadn't worked and reflowed it again, and physically poked it down with my tweezers our of desperation. Somehow that did it!

View attachment 36507

So after many many years of my GHz Pandora being broken, its finally back to life. The last problem it had before it died completely was the keyboard not responding, and thats fixed too!

Now all i have to do is replace the left joystick, since a attempted repair years ago left it in bad shape. That shouldnt be a problem though since I have an ICP1 from the ICP2 Kickstarter... I'm looking forward to all of the systems that the CC unit I have is too slow to run!
Congrats, that is a bit luck but I'm gladit worked!
 
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