Macintosh LC Takes Forever to Boot

[DistantStar001]

So I have a Macintosh LC III (in an LC II case) that takes about 10 to 20 minutes to power up and boot.  Once it does, it seems to work fine, but if it goes more than a few hours without a power on, it just sits there spinning its fan for an increasingly extended period with nothing on the screen.  I've tested the monitor with my DuoDock and it seems to work fine, so I know it's the computer.  I'm guessing that it's a failing capacitor, the question is which one?

 

[Compgeke]

Does it chime then take 10-20 minutes or does it make no sound and just take that long to get going? If you haven't already, you're going to need to recap as a first step, both logic board and power supply. With these particular systems, the caps aren't a "which one" but "Which one hasn't" unfortunately, and the longer they sit the more board damage they can do. 

Here's a list of logic board caps you'll need:

5x https://www.arrow.com/en/products/tajc476k016snj/avx

4x https://www.arrow.com/en/products/tajc106m016snj/avx

1x https://www.arrow.com/en/products/tajc107k006snj/avx

Total cost (including shipping) is $2.82. 

 

[DistantStar001]

It chimes after 10 to 20 minutes.  I figured that I would have to recap something, but my equipment is limited, and I've never dealt with surface mount capacitors before.  I haven't seen any sign of damage to the motherboard, but I know that the electrolytics used have a tendency to leak eventually.  The Good news is that the board was new-old-stock in the early 2000s and has only been used sparingly since.  

 

[Brett B.]

I'd be shocked if they haven't leaked.  ALL the caps in pizza box LC machines I have seen have leaked.  Even those that I know were rarely used.  I would almost lean more towards a power supply issue in this case, but it could go either way.

 

[olePigeon]

I've bought new-old-stock LC motherboards before, and they had leaked capacitors.  They don't have to have been used.

 

[PB145B]

I've bought new-old-stock LC motherboards before, and they had leaked capacitors.  They don't have to have been used.

Yep, the board that’s in my Macintosh Portable I purchased new-old-stock, and when I first opened the anti-static bag, it smelled like dead fish!

Age is the problem here.

 

[DistantStar001]

So I take it that my power supply is the current issue, and needs to be recapped ASAP.  But I shouldn't wait too long on the motherboard since that's going to be a problem sooner or later, and it would be better to deal with it before it does.

 

[olePigeon]

You might as well recap everything at once while you're doing it.  Save you a bit of money on shipping at the very least with a single order.