A1200 - Should I remove the shield?

[Sim085]

Hello, just got an A1200. Opened it and found that shield is all rusty. Should I remove it? Is it safe to do so? Also, it has kickstart 3.0 ... should I upgrade to kickstart 3.1 or there is something better?

[Predseda]

Dont be afraid to remove it, but you can also keep it there. KS3.0 is okay, dont worry. I also have one A1200 with rusty shielding, I only cleaned it with sand paper and put it back. But in fact, it has no purpose.

[john1979]

I removed the shield and the HDD cradle. Helps cooling.

[stu232]

I removed my shield simply because it made fiddling with the machine a little bit more awkward, never had a problem and no other electrical device has suffered any RF interference.

[fitzsteve]

As said you can safely get rid of the shield or you can rub it down, primer and re-paint if you want to keep it.

Some accessories for the A1200 will require that you remove it anyway, so if you're thinking of expanding it will probably go anyway!

As for Roms, 3.0 are fine for Workbench 3.0 and 3.1 only need to upgrade the Rom to 3.1 if you want to run OS3.9

[Retrofan]

I would buy some 3.1 kickstarts. AmigaKit has them cheap

As fitzsteve says you can paint the shield (black I would choose) with some antirust paint without primer.

[Sim085]

Hello again. I managed to remove the top shield. However I cannot understand how to remove the bottom shield. I cannot understand how I can disconnect the motherboard ports (ex: mouse port) from this. Does anyone know?

I need to remove this as this is clearly rusty.

[roy bates]

the motherboard is bolted to the shield through the back of the shield by the ports,just undo all the bolts on the ports and remove them.
and one near the front on the left on a clip that unscrews from underneath,and a few from the top to hold the motherboard down to the lower case.
the motherboard will now be free as a bird.

[Sim085]

Originally Posted by roy bates

the motherboard is bolted to the shield through the back of the shield by the ports,just undo all the bolts on the ports and remove them.
and one near the front on the left on a clip that unscrews from underneath,and a few from the top to hold the motherboard down to the lower case.
the motherboard will now be free as a bird.

Thanks for your reply. Just wondering; is it safe to put the motherboard in the case without the bottom shield? or?

[fitzsteve]

Hi Sim085,

Sorry I wrongly assumed you meant only the top part, you will need to keep the bottom part as it holds things like the mouse port in place.

Whilst the A1200 will function it will be loose as Roy says, I suggest restoring the shield or get a replacement, Airey36 on eBay normally sells them

[Sim085]

Originally Posted by fitzsteve

Hi Sim085,

Sorry I wrongly assumed you meant only the top part, you will need to keep the bottom part as it holds things like the mouse port in place.

Whilst the A1200 will function it will be loose as Roy says, I suggest restoring the shield or get a replacement, Airey36 on eBay normally sells them

Ok, at first I was only going to remove the top shield. But then saw the bottom shield rusted so I wish to remove that one as well. Will check ebay if it will need to be replaced.

Thanks

[roy bates]

check theres no saturation or dampness on the protective plastic sheet thats between the shield and motherboard.
on the motherboard side.

infact you could just give the plastic sheet a wipe clean and put it all back in.including the bottom shield.

[Jope]

Don't leave the bottom shield out.. It helps the motherboard stay in place.

[Amiga1992]

I don't remember exactly because I think I never had a RF shield on my 1200, and the A600 had one but it's been 18 years since I removed it :P But in some machines, like the C64, the RF shield also works as a dissipator of heat for some chips it touches, so it doesn't necessarily add temperature to the system, maybe the contrary (specially heat generated from a real hard drive might be "sucked in" by the RF shield). But you definitely don't need it and if it's rusty, throw it to shit. You will also lose a few grams of weight by getting rid of it.

Leave the bottom one alone, as Jope said, though.

[roy bates]

Originally Posted by Akira

I don't remember exactly because I think I never had a RF shield on my 1200, and the A600 had one but it's been 18 years since I removed it :P But in some machines, like the C64, the RF shield also works as a dissipator of heat for some chips it touches, so it doesn't necessarily add temperature to the system, maybe the contrary (specially heat generated from a real hard drive might be "sucked in" by the RF shield). But you definitely don't need it and if it's rusty, throw it to shit. You will also lose a few grams of weight by getting rid of it.

Leave the bottom one alone, as Jope said, though.

in the c64 that piece of reflective cardboard doesnt really do anything for heat dissipation.

you could get those little stick on heatsinks and bin that out,and be better off

[Sim085]

Hello to all again. I managed to remove the bottom shield. Found traces of water under this!!! There is also some rust on the motherboard connectors themselves.

Does anyone know how best to clean these connectors from such rust?

[john1979]

Originally Posted by roy bates

in the c64 that piece of reflective cardboard doesnt really do anything for heat dissipation.

you could get those little stick on heatsinks and bin that out,and be better off

A lot of the early C64s had a metal shield with fins touching the major chips so it doubled as a heatsink. Later ones had a cardboard shield, which as you say was as useless as a chocolate fireguard.

[demolition]

Originally Posted by Sim085

Hello to all again. I managed to remove the bottom shield. Found traces of water under this!!! There is also some rust on the motherboard connectors themselves.

Does anyone know how best to clean these connectors from such rust?

What part of the connectors has rusted? Or is it the expansion connector you mean (which is gold plated copper so shouldn't rust)?

First make sure everything is dried up. Rust in itself isn't too bad if it is not on a contact surface. As long as it is kept in a dry place, it won't do much. For cosmetic reasons you might like to remove it, and I use sanding paper for that, medium or fine grit. Just make sure to blow any metal dust off the parts before powering it on.

[prowler]

Originally Posted by Sim085

Hello to all again. I managed to remove the bottom shield. Found traces of water under this!!! There is also some rust on the motherboard connectors themselves.

Does anyone know how best to clean these connectors from such rust?

The best thing to use is a rust inhibitor that will convert the rust (oxide) to a stable phosphate which has a grey colour.

Something like this:



http://www.ebay.co.uk/itm/like/22124...f13=80&ff14=83

Now that you have the motherboard removed, you can apply it with an artist's paint brush to the connectors with the motherboard angled so that the liquid does not run onto the pcb.

Wait until all the rust has been converted and the liquid dried, then rinse the contamination away by applying tap water with the brush until it is clean. Then allow to dry again.

The phosphate coating will protect the parts from rusting again, so that you won't have to replace them.

[Nightshft]

As the bottom side of the Keyboard is connective and it could maybe touch parts of the mainboard or add-on card (for example it touches one part of my add-on card). Do you guys lay something insulating in between or insulate the bottom of the Keyboard - or just leave it as it is?