Post by soop on Nov 8, 2018 11:16:28 GMT
After getting some practice restoring some GTs that someone else had attempted (lifted pads, not cleaning the PCBs properly, exposing new traces and soldering on THT capacitors with long leads everywhere), I figured it was about time to restore my personal consoles from scratch.
I wanted to do this properly, or at least as properly as I was able, so I used hot air to remove the existing caps. To be honest, it wasn't the worst it could have been (you can tell by the fish smell how bad the caps have leaked). Technically, you're supposed to use a pre-heater to bring the whole board up to a uniform temperature to avoid uneven thermal expansion, but I don't have one, or the space for one, so I just tried to be as quick and efficient as possible. Plus, these boards are pretty thick and sturdy, so I figured the risk was justified.
In both cases, the caps came off easily without any lifted traces, so I'm glad I used this method. It was also quick, and I think much safer than the twist-off method.
Another maddening thing I've found from the hack-jobs, is that rather than remove the RF shields properly, they've just hacked at them with tin-snips to expose the caps (also leaving one right in the middle). It really takes a few minutes to remove them, although to be fair I've had practice now, and I have a desoldering gun (best £20 I ever spent) which I actually cleaned out yesterday and replaced the tip. It's really efficient now.
After that it was a case of cleaning the pads. I've found the most efficient way (by far) is to use a chisel tip to flow fresh solder onto each pad, and firmly move up any gunk, before cleaning off the solder with braid. It gets kind of like a plaque on the pads, but this method melts it off and around the edges, where I carefully scratched it off with an x-acto knife - you have to be careful to use the exact pressure to scrape the plaque into a powder, but not scratch the PCB coating - and then clean off the excess with isopropyl alcohol. Before I'd tried to scratch away at the plaque while it was on the pad, and this worked far less well and took longer to get a satisfactory result.
From there, it was time to solder new caps on (cap kit from console5). I only wanted to use SMD because THT caps always look ugly. You have to twist them around to make them fit, and SMD only cost a couple more bucks. The downside is that SMD is more difficult, or at least a distinct skill. There are also about three points on the board where I couldn't fit my preferred tip, so in lieu of removing the components in the way, I chose to use hot air. I tried a few times to use a smaller tip, but the join usually took too long to melt, risking burning out components. I might reconsider this in the future, but hot air seemed to work well.
So far, one of them popped it's fuse when I powered it on, so that's been replaced, and I'm waiting until tonight to retry it, but honestly I'm really happy with the work.
Images below of two different GTs, but one with a nice clean board and the other fully recapped. Also note that it's actually really annoying that the direction markings aren't exactly aligned even though I'm pretty sure the leads are!
imgur.com/a/zAA2Mmf
I wanted to do this properly, or at least as properly as I was able, so I used hot air to remove the existing caps. To be honest, it wasn't the worst it could have been (you can tell by the fish smell how bad the caps have leaked). Technically, you're supposed to use a pre-heater to bring the whole board up to a uniform temperature to avoid uneven thermal expansion, but I don't have one, or the space for one, so I just tried to be as quick and efficient as possible. Plus, these boards are pretty thick and sturdy, so I figured the risk was justified.
In both cases, the caps came off easily without any lifted traces, so I'm glad I used this method. It was also quick, and I think much safer than the twist-off method.
Another maddening thing I've found from the hack-jobs, is that rather than remove the RF shields properly, they've just hacked at them with tin-snips to expose the caps (also leaving one right in the middle). It really takes a few minutes to remove them, although to be fair I've had practice now, and I have a desoldering gun (best £20 I ever spent) which I actually cleaned out yesterday and replaced the tip. It's really efficient now.
After that it was a case of cleaning the pads. I've found the most efficient way (by far) is to use a chisel tip to flow fresh solder onto each pad, and firmly move up any gunk, before cleaning off the solder with braid. It gets kind of like a plaque on the pads, but this method melts it off and around the edges, where I carefully scratched it off with an x-acto knife - you have to be careful to use the exact pressure to scrape the plaque into a powder, but not scratch the PCB coating - and then clean off the excess with isopropyl alcohol. Before I'd tried to scratch away at the plaque while it was on the pad, and this worked far less well and took longer to get a satisfactory result.
From there, it was time to solder new caps on (cap kit from console5). I only wanted to use SMD because THT caps always look ugly. You have to twist them around to make them fit, and SMD only cost a couple more bucks. The downside is that SMD is more difficult, or at least a distinct skill. There are also about three points on the board where I couldn't fit my preferred tip, so in lieu of removing the components in the way, I chose to use hot air. I tried a few times to use a smaller tip, but the join usually took too long to melt, risking burning out components. I might reconsider this in the future, but hot air seemed to work well.
So far, one of them popped it's fuse when I powered it on, so that's been replaced, and I'm waiting until tonight to retry it, but honestly I'm really happy with the work.
Images below of two different GTs, but one with a nice clean board and the other fully recapped. Also note that it's actually really annoying that the direction markings aren't exactly aligned even though I'm pretty sure the leads are!
imgur.com/a/zAA2Mmf