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smeezekitty
May 1st, 2010, 06:51 PM
It has been exposed to moisture.
I removed the case to check and all seems good.
Put the case back on and power up, i see a white bar.
I took the case off, removed the mobo and put it back in, powered it on with the case OFF! and i saw a gray screen with cursor.
I put the case on and now its a white bar again.
Took the case off and it now shows garbled gray screen and the hard drive does not always spin up.
edit: Sometimes its striped.

Unknown_K
May 1st, 2010, 08:47 PM
You need to get some capacitors replaced on the motherboard, common problem.

tcpaehart
May 2nd, 2010, 02:41 AM
Water and electronics don't mix very well. the moisture shorts out the connections.

The electronic parts have specific current and voltage requirements, and if they are

shorted to a higher voltage, they usually get destroyed.

I had a pocket calculator back in the 1980's that went thru the washing machine by mistake.

Some of the keys still did things, but it never worked as intended again.

You likely will be unable to fix it, and would be better off looking for another one.

If you ever happen to get water in something electronic that is not waterproof,

you need to immediately remove the battery/power source and remove as much of the

water as you can find. You should disassemble the device and look for more moisture.

I have been told ( haven't tried it yet) that if you put the circuit board in the oven with just the oven

light on, it will drive moisture out. It may have to sit there overnight.

Or alternatively, find a sunny windowsill to set it on for about a day. ( you might want to keep

an eye on the temp. )

Good luck






It has been exposed to moisture.
I removed the case to check and all seems good.
Put the case back on and power up, i see a white bar.
I took the case off, removed the mobo and put it back in, powered it on with the case OFF! and i saw a gray screen with cursor.
I put the case on and now its a white bar again.
Took the case off and it now shows garbled gray screen and the hard drive does not always spin up.
edit: Sometimes its striped.

smeezekitty
May 2nd, 2010, 11:49 AM
Power was not applyed during moisture exposer.
Other then the internal battery which is only 0.1v

tezza
May 4th, 2010, 05:25 PM
I think capacitors are indeed a prime suspect. They can leak a little leaving conductive residue on the board.

If this is the problem, a last resort is to wash the main circuit board in the dishwasher (http://www.classic-computers.org.nz/blog/2009-04-13-mac-classic-2-dishwasher-fix.htm). Only recommended if you have got nothing to lose and probably only a temporary fix. However, it worked for me.

Tez

glitch
May 4th, 2010, 05:38 PM
It's definitely a capacitor problem. This is common of Macintoshes made in the same timeframe. I've never encountered a Classic II or LC series machine that didn't need recapped (of course, nonworking status is often why they come to me!). I've got a peanut can full of bad capacitors I've cut off Apple equipment over the years.

Yes, you can wash the motherboard in a dishwasher, it's actually fairly safe. We farm out some of our assembly work at my place of employment, and we recommend that the home assemblers wash the finished boards by running them through the dishwasher with no detergent. It removes the water-soluble flux right away. An even better solution is an ultrasonic cleaner, if you have access to one.

As long as power wasn't applied while the board was wet, it is unlikely exposure to water did much damage. The real problem is that slow drying allows corrosion between component leads or in chip sockets. If you think this is a problem, going over the board lightly with a fiberglass brush will usually take care of corrosion. If it's really heavy, apply liquid solder flux and reheat the pins of the corroded IC. A strong enough flux (we use Alpha 850) will float the oxides right off.

A tip about removing the capacitors: often the electrolyte weakens the bond between the trace and the board substrate. Heating the pad to remove the capacitor can cause the track/pad to completely detach. I use close-cut side cutters and snip the capacitor can off right above the black plastic base, then remove the leads individually with a quick swipe of the soldering iron.

tezza
May 4th, 2010, 05:54 PM
A tip about removing the capacitors: often the electrolyte weakens the bond between the trace and the board substrate. Heating the pad to remove the capacitor can cause the track/pad to completely detach. I use close-cut side cutters and snip the capacitor can off right above the black plastic base, then remove the leads individually with a quick swipe of the soldering iron.

yes, I briefly considered replacing the capacitors with mine. However, when I saw just how small the tracks were and the potential for damage I flagged that idea.

Tez

Floppies_only
May 12th, 2010, 07:33 PM
Yes, you can wash the motherboard in a dishwasher, it's actually fairly safe. We farm out some of our assembly work at my place of employment, and we recommend that the home assemblers wash the finished boards by running them through the dishwasher with no detergent. It removes the water-soluble flux right away.


I'll freely admit that I might not be too enthusiastic about eating off of dishes washed in the same washer that had cleaned a circuit board.

Sean

reject902
May 12th, 2010, 08:18 PM
Haha so I had an extra SE/30 lying about that was in pretty bad shape cosmetically. I had it sitting in the garage for the last few years and decided to bring it in and clean it up and play with it a little. First time it fired up just fine, second time the screen had a ton of garbage (not the checkerboard, a ton of vert and horiz artifacts) on it and wouldn't boot, or if it did it'd take 3-5 minutes to finally go to the grey screen and load. Well needless to say I did the usual, checked and reseated the ROM and SIMMs, replaced the PRAM batt. Still nothing. Well, since I wasn't really concerned with it at this point and having noticed some corrosion from the ever so notorious capacitors, I decided might as well give it a wash. So I removed the PRAM and tossed it in on the 'old "Pots & Pans" setting (with NO detergent) and let the whirlpool have a whirl. Two days of letting it dry out later, it's firing back up just find. This fix is temporary tho. They'll leak again and cause their havoc, so they really need to be replaced. But if you're desperate and don't want to tackle capacitor replacement, from personal experience it does work. Just remember your mileage may very.