(Topic ID: 254774)

So I have alkali damage... now what?


By KDPinball

3 months ago



Topic Stats

  • 25 posts
  • 15 Pinsiders participating
  • Latest reply 3 months ago by PinballManiac40
  • No one calls this topic a favorite

You

Linked Games

Topic Gallery

There have been 4 images uploaded to this topic. (View topic image gallery).

16F393B8-51BF-4154-8180-1D746618C09A (resized).jpeg
FC4811B1-5474-422F-BCC3-15973B2C16B6 (resized).jpeg
55C18FF1-E7E3-48BE-ABFE-3CF9B5E99F8C (resized).jpeg
IMG_3159 (resized).JPG

#1 3 months ago

Hello all. I picked up a Pin*Bot today at an auction, and there is a small amount of corrosion on the board, presumably from the batteries. Now, I can't see any discolored traces, but the there are a few pins on U42 and the resistor next to it that are corroded.

What's my next move? Would there be any problems with removing/flushing the board, or do I have to take drastic measures? The machine boots and seems to work well (except for a dead display), so is drastic action even necessary?

Thanks for all the help, I am a bit in the dark here as this is the first machine I have bought personally.

IMG_3159 (resized).JPG
#3 3 months ago
Quoted from KDPinball:

but the there are a few pins on U42 and the resistor next to it that are corroded.

That is a capacitor and not a resistor.

Quoted from KDPinball:

What's my next move?

I would carefully cut off the battery holder and inspect underneath for more damage.
Hard to say but there maybe something on U-52 too. Post a pic after you remove the battery holder.

-2
#4 3 months ago

Clays guides explain how to remove/repair acid damage. You could also just buy a new board and change it out.

#5 3 months ago
Quoted from Daditude:

Clays guides explain how to remove/repair acid damage. You could also just buy a new board and change it out.

It's working fine and it looks like almost no damage at all, so I miss your winking smiley after the last sentence.

#6 3 months ago
Quoted from sven:

It's working fine and it looks like almost no damage at all, so I miss your winking smiley after the last sentence.

Winking smiley??

I'm not sure what you mean. He asked for options. I gave him the best 2.

#7 3 months ago
Quoted from KDPinball:

The machine boots and seems to work well (except for a dead display), so is drastic action even necessary?

Yeah, you want to arrest the corrosion you DO have before it gets worse (i.e. gets into the traces). The good news is it looks extremely minor and should be easy to clean up.

#8 3 months ago
Quoted from vireland:Yeah, you want to arrest the corrosion you DO have before it gets worse (i.e. gets into the traces). The good news is it looks extremely minor and should be easy to clean up.

This.

I just rebuilt a Sys80 MPU with some stout damage, get it cleaned up. If its working, great! No reason to replace the MPU. Get rid of the battery holder (remote pack or nvram) and neutralize with zep acid based toilet cleaner, stuff works great. $4 at Home Depot.

#9 3 months ago
Quoted from sven:

It's working fine and it looks like almost no damage at all, so I miss your winking smiley after the last sentence.

Agreed. I don't see anything that remotely warrants a replacement.

#10 3 months ago
Quoted from Daditude:

Clays guides explain how to remove/repair acid damage. You could also just buy a new board and change it out.

Not acid,
Alkaline damage.

#11 3 months ago

Luckily, this is very minor damage and shouldn't be a very long or time consuming fix.

#12 3 months ago

Here’s a photo with the battery holder removed, as far as I can tell there’s only acid damage on the terminals.

55C18FF1-E7E3-48BE-ABFE-3CF9B5E99F8C (resized).jpeg
#13 3 months ago
Quoted from KDPinball:

Here’s a photo with the battery holder removed, as far as I can tell there’s only acid damage on the terminals.[quoted image]

Hard to tell from the resolution, but it LOOKS like two pins at the right end of the chip at U42 are corroding, too. Maybe got dripped on? I'd check everything DOWN from the battery holder carefully.

#14 3 months ago

On a side note, once you clean off any residual - install a NVRAM and be done w/batteries.

If you need to install a socket, find a local tech if you aren't comfortable w/desoldering a chip w/a lot of pins.

#15 3 months ago
Quoted from Daditude:

Clays guides explain how to remove/repair acid damage. You could also just buy a new board and change it out.

no need for this whatsoever, send it to someone like Rob Anthony and let him repair it, its not that bad but needs to be cleaned up correctly.

#16 3 months ago
Quoted from vireland:

Hard to tell from the resolution, but it LOOKS like two pins at the right end of the chip at U42 are corroding, too. Maybe got dripped on? I'd check everything DOWN from the battery holder carefully.

All the top pins on U37 are suspect, as is the little green (capacitor?) to the right of U42. I'd say on U42 itself, it's the SIX pins on the right, with the two closest to the center probably okay, but those 4 adjacent to the right end? Definitely.

Just neutralize what you can find and clean the acid off you use to do it. This thing is far, far from a difficult fix. Unlikely to even need to unsolder anything anytime soon.

+1 on the NVRAM or remote battery holder.

*Edit* If you don't know what you're doing, don't even think about working on the board with a soldering iron. Solder that's been corroded is harder to work with, and you're more likely to pull a trace when removing components. Battery damage and corrosion is one of the few things I recommend people use a tech for, and I've never paid a tech in the 7 years I've owned games (because I chose to replace boards..all the ones I had with acid damage were massively damaged across 40%+ of the board. Yours is VERY salvageable!). If you screw something up with poor rework, most techs won't even touch it at that point, much less the few that are actually good at repairing alkaline damage.

#17 3 months ago
Quoted from Frax:

Just neutralize what you can find and clean the acid off you use to do it. This thing is far, far from a difficult fix. Unlikely to even need to unsolder anything anytime soon.

What acid would I use to neutralize it? And is there any type of cloth you would recommend? I thought I had to desolder the ICs since some of the acid could get underneath and cause further issues. I do agree with you though, I’d rather not have to solder if possible.

Thanks for all the responses everyone.

#18 3 months ago

Start with vinegar and a soft brush. Rinse with distilled water.

If you're not happy with those results there is a thread here about using a strong acid, search around for it.

#19 3 months ago
Quoted from YeOldPinPlayer:

Start with vinegar and a soft brush. Rinse with distilled water.
If you're not happy with those results there is a thread here about using a strong acid, search around for it.

I have used vinegar and Zep, skip the vinegar and go right to Zep.

#20 3 months ago
Quoted from gdonovan:

I have used vinegar and Zep, skip the vinegar and go right to Zep.

Ditto^^, but find the thread about it. I've done it, works well.

#21 3 months ago

So I made one pass with vinegar/water/isopropyl alcohol, and here are my results. Is this properly neutralized, or do I have to see metal shine to signify that the battery acid is gone?

FC4811B1-5474-422F-BCC3-15973B2C16B6 (resized).jpeg16F393B8-51BF-4154-8180-1D746618C09A (resized).jpeg
#22 3 months ago

no, still needs cleaned and sanded to prevent future damage. just because you can't see, doesn't mean its not there. stuff seeps into all kind of nooks and crannies, you're eye isn't trained to see what a pro sees.

#23 3 months ago

Update: I put in a remote battery holder and put the board back into the machine. The machine still boots, and is successfully saving settings with the new batteries.

Thanks for all the help everyone.

#24 3 months ago
Quoted from KDPinball:

Update: I put in a remote battery holder and put the board back into the machine. The machine still boots, and is successfully saving settings with the new batteries.
Thanks for all the help everyone.

Use lithium. A lot less likely to leak. Cheap insurance.

#25 3 months ago

With some soldering, the 6116 NVRAM will never leak and this one has 124 year retention rating. No insurance needed with it.

https://www.pinitech.com/products/6116_nvram.php

Promoted items from the Pinside Marketplace
$ 36.99
Eproms
Matt's Basement Arcade
2,999 (Firm)
Machine - For Sale
Richfield, MI
$ 50.00
$ 9.00
Electronics
Yorktown Arcade Supply
$ 17.00
$ 10.00
Cabinet - Sound/Speakers
Gweem's Mods
From: $ 40.00
Cabinet - Other
Rock Custom Pinball
$ 44.95
Playfield - Toys/Add-ons
PinBoss Mods
$ 18.99
Eproms
Matt's Basement Arcade
$ 175.00
Lighting - Interactive
Professor Pinball

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside