Today i've tried to fix my Fixeight board. Despite having a broken jamma edge that i still need to take care of (will take any advice, for now my best plan is to fix it to some wood or plexi and use a jamma extender to avoid any further load on this already fragile piece)
The problem was obvious : horizontal lines across the screen, all the time.
After visual inspection (everything looks fine), i've started pushing gently on components, and bingo, the problem was from a Toaplan custom chip. Having just a very light push on it makes the problem disapear, so it was for sure a cold joint issue.
I've decided to take a wooden toothpick and start pushing on legs to see which was the culprit. It was the second pin under that 105 mark, so i guess it's pin 106 ?
Having no experience at all with SMD soldering, i've tried first with my clean iron tip and push gently on it with some flux, no luck. I was too afraid to bridge anything, so i've bought some solder paste. After a few try on an old motherboard (and realise that the default needle will give way too much paste), i've decided to go for real.
I dipped a sewing needle on the top of the paste tube to get a very light touch of it, applied some flux and tried to dispose it. Paste somehow melted with flux, i was hopping for the best. I put Kapton (well, Koaptan, thanks China) all around to try and protect everything, and start applying hot air, at 275. Within a few seconds (having such a low quantity of solder paste probably helped), it was ok, but two pins where obviously bridged. Damn.
I then took my soldering iron, some flux, and was able to remove the bridge by dragging it down in one or two shots with a very clean tip.
After that, it was probably not the cleanest job on earth, but using magnifying glass and my multimeter seems to tell me that there was no bridge. I can't really trust it though, as my multimeter was telling me that the pin was perfectly fine on the board and was making good contact, but it wasn't the case since i had to push it with a tooth pick to work.
Cleaned it, and here's the result (coin for scale) :
No visual bridge, even if it looks like here on the pic but i guess it's shadow from each leg.
After letting it dry for a bit, here's the final test :
I guess now it's a FIXEDEight
The problem was obvious : horizontal lines across the screen, all the time.
After visual inspection (everything looks fine), i've started pushing gently on components, and bingo, the problem was from a Toaplan custom chip. Having just a very light push on it makes the problem disapear, so it was for sure a cold joint issue.
I've decided to take a wooden toothpick and start pushing on legs to see which was the culprit. It was the second pin under that 105 mark, so i guess it's pin 106 ?
Having no experience at all with SMD soldering, i've tried first with my clean iron tip and push gently on it with some flux, no luck. I was too afraid to bridge anything, so i've bought some solder paste. After a few try on an old motherboard (and realise that the default needle will give way too much paste), i've decided to go for real.
I dipped a sewing needle on the top of the paste tube to get a very light touch of it, applied some flux and tried to dispose it. Paste somehow melted with flux, i was hopping for the best. I put Kapton (well, Koaptan, thanks China) all around to try and protect everything, and start applying hot air, at 275. Within a few seconds (having such a low quantity of solder paste probably helped), it was ok, but two pins where obviously bridged. Damn.
I then took my soldering iron, some flux, and was able to remove the bridge by dragging it down in one or two shots with a very clean tip.
After that, it was probably not the cleanest job on earth, but using magnifying glass and my multimeter seems to tell me that there was no bridge. I can't really trust it though, as my multimeter was telling me that the pin was perfectly fine on the board and was making good contact, but it wasn't the case since i had to push it with a tooth pick to work.
Cleaned it, and here's the result (coin for scale) :
No visual bridge, even if it looks like here on the pic but i guess it's shadow from each leg.
After letting it dry for a bit, here's the final test :
I guess now it's a FIXEDEight
