I have a heavily yellowed IIGS which I'd like to retrobrite, but am worried that the hydrogen peroxide will cause the shield to rust.
Given that the shield is effectively welded to the case, is there any good way to remove it and put it back? Thanks!
I have no experience with that.
I would try a few drops on the shield to see if it reacts. If it doesn't react after "some" time you should be good to go.
I mean with normal water it won't rust if you dry it thoroughly after.
Yes, don't try to remove it. If you rinse it very thoroughly when it's done, you'll be fine. I wouldn't do more than a few hours at a time, though, and not with more than 3% H2o2.
I had the same concerns; however, in my case the shield already had some rusting etc.
So I decided to take it off by snipping the melted plastic points. I cleaned the shield with evaporust and then ended up spray painting it to prevent further rusting and for asthetic reasons. I know that it eliminates any grounding ability- but I don't think it's super important for that on the IIgs. From an actual RF perspective - it seems most Youtubers like Adrian Black etc. just toss the shields anyway . . .
I ended up using hot glue on the same plastic points to resecure the shield. Again not likely to be the best solution, but it's what I came up with at the moment.
Overall I think it turned out ok. If your shield is not rusted at all - it might be easier to leave it on. In all other videos I've seen on retrobrighting though - it seems like everyone really strips things down to just the plastic.
In C64 machines only because of the overheat produced and the rarity of the ICs involved. IMHO, this does not apply to the Apple II line.
I don't know this and curious if you knew? I do know on a separate video I had watched by Adrian Black - a Mac absolutely used the shield as part of the grounding (I think it affected the speaker/audio when he removed it).
I've removed the shield on several of my IIGS's. I would argue that the issue of bespoke chips and overheating is quite germane to the IIGS; several of the chips on the board are more difficult to source than many C64 chips and some are just plain unobtainable. Furthermore, a pile of dead ROM00/01 boards like I have won't necessarily help you if you have chip issues on a ROM03 board. If you add a Transwarp / ZipGS, VidHD, CFFA, Uthernet and a decent memory card, heat can become a problem.
As for grounding, a common problem is actually the motherboard itself shorting on the bottom shielding - otherwise grounding is not something provided by the case shielding.
I use a hot air tool on low to slightly melt the "nubs" and pull the shield off. Yes, you can clip them, but this method obstensibly lets you out the shield back on if you want, as the nubs are just melted plastic rivets anyway.
You must remove those shields.
They attract rust like oil attracts dirt.
Enough superglue at the points where the plastic dots were will stick the shield back on. And don't worry about too much glue seeping everywhere. Just hold it until the glue sticks.