Build Your Own Arcade Controls Forum
Main => Main Forum => Topic started by: unix4hire on March 12, 2005, 01:11:49 am
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I sent my faulty pacman PCB to twobits.com for analysis and was informed it had quite a bit of corrosion. They said the could fix it for $111 by sandblasting it.
First off, is sandblasting a somewhat standard procedure to fix corrision problems on PCBs?
Second, is that a good price? THey said they would run it for 24 hours after fixing it before sending it back to me, which sounded like a good idea.
I figure, for $111 I could have a fully working pacman cabinet (free gift from a church) and you can't really beat that.
--Erich
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If they say they could sandblast a pcb to make it work, thats news to me let me know how it goes :o
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I would suggest solvents. I played around with a answering machine PCB that suffered severe water damage, and found that acetone and alcohol will dissolve nearly all of the corrosive salts. I never tested it (it having previously suffered severe physical damage from me), but it looked fine.
Sandblasting will probably work, but it will remove the silk screen, and you would probably need to reflow all of the solder joints.
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Actually, bead blasting is a prtty common practice used to clean up the battery corrosion on damaged pinball MPU boards. Yes it takes off the silkscreen, but you are pretty much assured that all of the corrosion wil be removed. As long as the person knows what they re doing, it is a very fast an d effective way to go about it. I have used chemical washes (50/50 mix of water and white vinigar) and then sanding to remove corrosion on MPU boards and it's not as effective as bead blasting.
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Too bad you already sent your board off, you could have sold it on the bay nonworking for close to $100 and simply bought one of the jamma ones for $95.
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...simply bought one of the jamma ones for $95.
Where? On ebay?
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Hi,
Check this article out. While it is mainly focused on Acid repair for Pinball MPUs.
the same process applies for your board.
http://www.repairconnection.com/acid_damaged_mpu.htm
Also http://marvin3m.com/bally/index1.htm
has the following to say
Bead Blasting.
A bead blaster is mearly a sandblaster, but instead of shooting sand, it shoots small ceramic beads. This is much gentler than sand. To bead blast a board, all the corroded electronic components should first be removed that are in the effected area. Then the board can be bead blasted (after bead blasting, the board should still be neutralized with vinegar, as discussed below). Finally, new components are installed to replace the old ones.
Some people claim bead blasting is not a good way to remove corrosion, as it "embeds" the corrosion deep into the pores of the circuit board, making it impossible to remove at a chemical level. This may be true, but many commercial board repair establishments use this technique to remove corrosion (probably because corrosion can be removed quickly, with a very professional "look", using bead blasting). Most individuals don't have the means to bead blast, so it's not worth arguing this point here. But please keep this in mind.
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Just thought I'd point out media blasting equipment ranges from huge pressure pot setups used to expose the aggregate in concrete to airbrush sized units used to etch glass. Blasting media likewise ranges from very course to extremely fine powder. By varying the air pressure and media used, you can clean a lot of things you'd never expect to survive being blasted.
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Just thought I'd point out media blasting equipment ranges from huge pressure pot setups used to expose the aggregate in concrete to airbrush sized units used to etch glass. Blasting media likewise ranges from very course to extremely fine powder. By varying the air pressure and media used, you can clean a lot of things you'd never expect to survive being blasted.
yeah.. I've seen people blast the paint off an aluminum soda can.. that's pretty delicate. I would say its not as harsh as it sounds. I suppose the folks at TwoBit know what they are doing.. I've never heard anything bad about them.
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I have a sandblaster to etch in glass. You can take paint off things and not even harm them.
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I've done a lot of sandblasting in my time, but all in an automotive setting. I would assume that with the right media and pressure it could be done without damaging the board. I see removing the silkscreening as a pretty major drawback though.
-S