PowerBook G3 Kanga Part II: Reflowing ad nauseam

Hello darkness my old friend…


Last we left the Kanga, it was being a bit of a pain: It was suffering from an issue where it would display a distorted image–one that was interrupted by some black and white stripes every other pixel or so.

I did some more digging (and pushing the system) to try and see if this was an issue that could be fixed, or if it was one where I’d have to throw in the towel and phone in the likes of someone more experienced. As I played around more with the PowerBook, I found that the problem would go away temporarily if I applied pressure to a part of the bottom casing and refreshed the screen, either by dragging a window around to make the system redraw whatever was behind it, or by changing the color depth.

I later did more prodding by opening the PowerBook up and sticking the blunt end of a toothbrush down where the trackpad connector was. If I held slight pressure there? Problem would go away. Minute I pulled off of it? Artifacts reappeared. This quickly confirmed that this was a problem with a bad solder joint somewhere on the board, ostensibly on something to do with the video circuitry.

To make sure this wasn’t something dumb and more tragic–like the screen ribbon cable–I also hooked up an external monitor to the VGA port and yep, the artifacts appear on external too. So definitely not a ribbon cable. Whew.

With the help of the one and only dosdude1, I took a picture of the bottom of the board and he pointed me at where the video circuitry was: A CHIPS GPU and the associated VRAM, all right next to eachother. Neat.

Now, being absolutely overly paranoid that I was going to destroy this poor thing, I set my hot air station way too low: 200C. I did a 5 minute run with that, put it back together enough to test, and it seemed to work, even through some extended testing. I proclaimed victory, went to bed, and that was that.

Turns out solder will start to melt around those temps…if it’s the leaded solder that most of us use, with the proper mix to allow it to melt at that low of a temperature. What I probably needed was to boost the temperature by a sizeable amount–probably closer to 280-300C.

Nonetheless, that wasn’t going to stop me from going to bed happy. The next morning however…problem was back in full force, and I asked around before committing to yet another teardown. Thankfully once you get used to tearing down these PowerBooks they come apart fairly simply, so there’s that.

Knowledge in mind, I once again pulled the board from the Kanga, took it out to the garage and blasted it with 290C from my hot air station. Realized midway through that I used too much flux and that was a fun thing to have to clean up. Once that was done, however, I brought it back onto my desk, put it together enough to test, plugged it in and


uh oh

Did I just kill this thing? Oh crap. Oh crap. 

Gave it another once over with some 90% IPA and let it dry. Same thing happened. And it kept happening. I was now in full shitting bricks mode.

Before taking any drastic action, though, I opted to crudely connect the internal display to the logic board, hit the power, and



The absolute rush of relief that flowed over me at the moment I heard the chime and saw the floppy disk pop up on the screen. I didn’t kill it. Maybe it got angry and was expecting something to display to and got super mad when it couldn’t find such a thing. Either way, I conquered this machine hopefully for good. Time for dinner.
Over dinner, I got to talking with dosdude1 about the repair again and he mentioned that it’s a possibility that 290C wasn’t enough. So, I opted to return to the workbench and go over it once more at 320C, in hopes that finally, this would do it. One final test before putting it back together, and everything looked great!
Now, I wish I could tell you that this is the end, the Kanga is living out an awesome, trouble-free life. But after all this I opted to tear into another thing I got with the Kanga: A Color StyleWriter 2200 complete in box. I needed a machine to print from, why not the Kanga we just fixed?
Alas, midway through installing the software from the original floppies, the dreaded artifacts popped up again. Damn it. Damn it all to hell.
However, during that 320C run, I definitely gave the GPU itself enough heat, such that the chip began subtly shifting around the board as I moved the hot air nozzle over it. So I don’t think that anything under the GPU chip is the issue. Given the nature of the issue (and how the artifacts don’t like, crash the system or anything), and advice from others…the problem looks to be the VRAM not making good contact, and that’s…believable.
When I did hot air rework on my Power Mac G3 blue and white when having to replace the ATA chip, I got hit by this issue too. It looked like it was making a good connection, but it actually wasn’t. After I went in with a soldering iron and manually touched up all the joints, that was enough to bring it back to function.
That’s my next play: Going in with my soldering station and reflowing the VRAM manually with my soldering iron to make damn sure all the joints have been given fresh flux and solder and that they’re VERY stuck down.