Well Crap (SE/30)

[JustG]

I finally got brave and cracked the case on a SE/30 that was given to me.  It had been sitting in a hot garage for a number of years.



Needless to say, maxcell bomb strikes again.  It was getting dark so I don't have any more pictures.  The chassis is pretty bad too.  I'm inspired by @PotatoFi's SE  thread so I'm going to attempt a repair.  First round of soaking is under way now.  Hopefully I can get it fixed, the guts were going to find their way into @maceffects clear case.

 

[maceffects]

Aside from the issues with the ROM SIMM socket and possible bad traces, it looks quite tame.  If those two main parts are good, I suspect this would be a fairly easy fix.  I'd recommend nickel plating the chassis once the rust is all gone and a a rust inhibitor is applied.  It will make it looks nicer and last longer. 

 

[PotatoFi]

Agreed, this looks pretty good as far as Maxell bombs go! Keep us updated!

 

[JustG]

So far I've been lucky and have dodged a bad battery so I'm just disappointed that my SE/30 was the one to suffer the damage.  I'm definitely going to start looking for a place to do nickel plating once I've done the clean up.

Updates with photos are sure to follow.

 

[Bolle]

This looks like it's still fresh. Don't take too long to clean it up and I'd say this is a good candidate to survive the battery disaster without needing too much work.

 

[IlikeTech]

Also, please wear gloves.  That battery crap is no joke.

 

[JustG]

Thanks for the words of encouragement!  Board has gone through an initial rinse and scrub.  I'll be going over everything with deoxit this weekend.  I have a few missing components near the battery damage which I will need to identify and replace:

D1 and D2 are diodes (I think) would anyone happen to have a mouser/digikey part number for those two?

Y1 is a crystal, same question as above, is there a part number available for replacement?

I'll take some more pictures throughout the cleanup process.  YK4 RTC looks pretty bad, hopefully it'll work after a good cleaning (or three).

 

[JustG]

This is the damaged section of the logic board after an initial rinse and dry.  Still not sure what goes in D1, D2 and Y1:



And a before beauty shot of the chassis:



Still plenty of work ahead of me.  Hopefully the floppy drive will have survived.  I've got a Classic that I started on before I opened the case on this one so it's about finished then I'll really start working on this one.

 

[maceffects]

Missing voltage regulators it appears

 

[davidg5678]

Still not sure what goes in D1, D2 and Y1:

I think Y1 is a 32.768Khz Crystal, like this one: https://www.digikey.com/product-detail/en/ecs-inc/ECS-327-6-13FLX-TR/XC2128CT-ND/5875611

D1 and D2 are 1N914 Diodes. I found some for sale on Digikey, but they are all through-hole instead of SMD. If you can't find any SMD diodes somewhere else, these should still work just fine. There are three pads on the SMD package, but only two are used, so these two-legged diodes will work either way as long as they are installed with the proper polarity. https://www.digikey.com/product-detail/en/on-semiconductor/1N914/1N914FS-ND/978749

I gathered these values from the SE/30 Schematic re-creation PDF, which you may also find of use in repairing your motherboard. https://drive.google.com/drive/folders/10VO6n72vsn52xqMyOgSZpi11tbyv7_Yx

 

[Bolle]

Leave the diodes and the crystal out for now and see if you can get the board to boot at all at first before spending money on parts.

Those parts are not critical for the board to work. Without the diodes you won't be able to use a battery and without the crystal the clock will not advance in time.

 

[JustG]

Thank you @davidg5678 for the links and the schematic.  Both will come in handy.  @Bolle great plan, I'll recap the board and give it a shot before throwing parts at it.  I should have enough spare caps.  Updates to follow.

 

[Alex]

A really unusual logic board cleaning process. WD40?

Please consider viewing to evaluate if this process helps in your situation.

I wanted to introduce you to a really unusual process of cleaning a board, I have never tried it but it's presented here in this video. It involves using WD40 (I told you it was unusual) on the board to clean it. Of course if you do this you will have to really do some serious post clean up. It was a while since I watch this video but when I saw your post I immediately remembered this video.

 

[JustG]

I just watched his video last week.  I may give that a shot if the board is dead after the recap.  I'm a little worried that the WD40 might eat away at more than the corrosion.  That was a great video series by the way.  Highly recommended for anyone who hasn't watched them yet.

 

[Stephen_Usher]

Well, WD-40 (or, Water Dispersant No. 40) is a reducing agent, designed to remove oxidation so as to allow engines to start after the high tension side became damp, so it makes sense that it would reduce the oxidation caused by the leakage, possibly redepositing copper.

 

[Alex]

Short comment, as per this shot.

I have an iMac G3 and the metal chassis suffered a similar fate. I would clean it with some vinegar and with extremely fine sand paper (the kind that you can work with when wet) — sand and sand until all that rust is gone and then you can spray paint that part. I did this and it turned out really well. Considering how it looks, I doubt there is anything to lose.

Cheers!

—Alex

 View attachment 34899

 

[trag]

Rust-oleum sells a phosporic acid product which is great at removing rust.  The phosphate displaces the oxide on iron and forms a tough coating of iron phosphate which has a black/grey color, doesn't flake off and takes paint well.    However, I wouldn't recommend it if you're planning to electroplate with, e.g., chrome afterwards.   I don't know if it is conductive, and other metal might not plate onto it well.    It is fantastic if you just want a durable, corrosion resistant surface or if you want to paint over it.

"Rust Dissolver"

https://www.autozone.com/miscellaneous-cleaners-and-degreasers/rust-remover/rust-oleum-rust-dissolver-1-quart/

 

[ScutBoy]

I've used a product called "Ospho" (?) which is also a phosphoric acid product in automotive applications, and it's worked well. Like trag's product, it leaves a slightly rough surface that can take paint.

You can get it at Ace Hardware stores (they can order if it's not in stock) or at automotive stores.

 

[JustG]

I've wanted to try out Evapo-Rust, the gentleman over at Hand Tool Rescue on YouTube (another great channel) seems to like it.  On the other hand, I've got a couple friends with media blasters so I may just go that route.  I'd really like to explore chrome or nickel plating, chrome is not going to be cheap but for something I plan to display, I might just spring for it.