LC 475 prone to cap leakage as other LCs

[feltel]

I got myself a lot of three LC475 and one LC. One is missing its RAM and VRAM modules, the others are complete. The batteries are flat, so I cannot test them right away. The boards look dusty but okay and they do not have any signs of cap leakage. I'd like to ask if the later LCs are also prone to cap leakage as the previous generations and the compact Macs of the same era.

 

[3lectr1cPPC]

All Macs with those caps pre-1995 will leak. 1995 and up they typically don’t leak but still can stop working. The 475 is from 1993, so it’s included.

 

[joshc]

1995 and up they typically don’t leak but still can stop working.

Have you got a definitive source for this other than anecdotal knowledge? I’ve seen photos of G3 and G4 boards with visible leakage on them, so it’s definitely possible.

Wether a machine needs cap replacement depends on a lot of factors, mostly storage and usage during the capacitors life. Other factors include the manufacturer and ratings of the capacitors.

But yeah, 475s definitely need replacement caps on the logicboard and power supply.

 

[3lectr1cPPC]

I've heard people talk about seeing caps on systems that new leak, but I've never seen any photos or evidence of it so I can't say for sure. What I can say is that that is extremely uncommon, as evidenced by the thousands of systems from that era that work fine. That's not to say that no caps are failure prone from that time - eMacs, iMac G5s, various power supplies from the time got hit by the capacitor plague. That's a different type of capacitor though and a different type of failure.

I'd believe that some SMD caps from that time have leaked, but it's clearly the exception to the rule.

 

[Scott Baret]

The iMac G5 was notorious for bad capacitors too.

 

[3lectr1cPPC]

Wow, you're one post away from 5000 scott!

 

[feltel]

But yeah, 475s definitely need replacement caps on the logicboard and power supply.

Okay, thanks alot. I'll count the needed caps and do another round of recapping.

 

[CircuitBored]

I've heard people talk about seeing caps on systems that new leak, but I've never seen any photos or evidence of it so I can't say for sure. What I can say is that that is extremely uncommon, as evidenced by the thousands of systems from that era that work fine. That's not to say that no caps are failure prone from that time - eMacs, iMac G5s, various power supplies from the time got hit by the capacitor plague. That's a different type of capacitor though and a different type of failure.

I'd believe that some SMD caps from that time have leaked, but it's clearly the exception to the rule.

PowerMac G4 logic board with leaky capacitors.

The capacitors in Quicksilver PSUs are also garbage and prone to failure/leakage. Computers from that era are by no means problem-free and it's a bit silly to assume otherwise, honestly. They're twenty years old and electrolytics have comparatively short service lives.

 

[3lectr1cPPC]

I didn’t say they were problem free, I said they don’t leak as often. I mentioned PSU issues too.
Anyway, that image is strange. Looks to me more like something was spilled there, the gunk on the top and sides doesn’t look like any cap leakage I’ve seen. Looks like it was stored in a wet environment and the metal just corroded.

 

[joshc]

@3lectr1cPPC i think you just need to be careful saying post 1995 don’t typically leak as I don’t think that’s very accurate.

 

[3lectr1cPPC]

I’d just be curious to see statistics on that. I mean, I’m all for replacing caps preemptively. I’ve recapped my 1997 PowerBooks and earlier, with plans to go newer too, including recapping my Sawtooth at some point. And I know a select few have had caps that new go bad as well, like in the 3400s. I just haven’t seen much evidence that they physically leak like the older ones too. That one image looks like something else happened. And they certainly do fail past that! The 2000s cap plague machines do “leak” but it’s out the top and a dry substance.

 

[robin-fo]

I have a 475 without any recapping done yet and still 100% working, but recapping will certainly be necessary soon.
Btw you can boot these machines even with a missing battery if you flip the power switch, wait 1-2 seconds, flip it back and switch it finally on after <1 second (or so).

 

[matttintoshplus]

That's a different type of capacitor though and a different type of failure.

What do you mean by this? How are the capacitors in the power supply different than those in the motherboard?

 

[3lectr1cPPC]

The motherboard caps are surface mounted, while most of the time the PSU caps are through hole, which means they are mounted via being soldered in holes through the board. It’s honestly a bad comparison though because both are electrolytic caps that can leak. My main point was that during the capacitor plague of the 2000s, those through hole caps were the main ones affected and leaked out the vents in the top, not out of the rubber seal on the bottom. However, plenty of older through hole caps do leak out the bottom, such as the ones on the Mac Classic analog boards, LC, IIsi, etc. power supplies. These were rarely found on MAC logic boards in the 90s though, they wanted to keep everything low profile.

 

[matttintoshplus]

Earlier you said that in the early 90s was when Macs were plagued with the bad caps, were there just two main time periods when poor caps were produced?

 

[3lectr1cPPC]

Yes and no. The caps from that late 80s-mid 90s time period where we see so many failures nowadays were mostly fine back in the day when the machines were current. A couple instances of bad caps started showing up in the later half of the 90s and then people began to catch on to the issue in the early 2000s, which has only gotten worse until today where those era of caps have a 100% failure rate. And still, it's only certain types of electrolytic caps. The Surface-Mount (SMD) type are the infamous ones that leak on mac logic boards starting with the SE/30 and rev b Mac Iis. Plenty of through hole caps from this time fail just as often, such as the ones on Mac Classic analog boards, anything with ELNA-brand caps (IIsi PSU, PowerBook 1xx PSU, a bunch of Toshiba laptops, etc) is experiencing devastating leaks, and other brands go too. Not 100% of the brands are bad from this time though, but due to how many there are it's good to replace anyway, they're old.

Early 2000s caps are separate though. The story goes that someone stole a capacitor formula from a company and through a game of recipe telephone it got mis-copied around, causing probably millions of badly formulated caps to end up in power supplies, motherboards, graphics cards, and more. They'd work at first but bulge out the top and start leaking a dry crusty buildup from their top vents and stop working. This happened when systems with them were new and current, and things didn't fully smooth out until the end of the 2000s. The main difference there is that those plague caps weren't as damaging to things around them because they didn't leak liquid electrolyte from the bottoms (usually), and it's easy to see if they're bad. (If the top vents are bulging or have a brown or orange or black residue on them, they're bad).

So yeah, two different situations.

 

[volvo242gt]

As someone who owned a G4 DA that had the dead fish smell, quiet audio, and erratic performance of leaky capacitors about 8-9 years ago, I can attest to the fact that post 1994 machines are just as likely to develop cap issues as the 1989-94 machines are. In fact, I plan to get my G4's board recapped, even though it seems fine right now.

 

[3lectr1cPPC]

Your situation has always puzzled me. I 100% believe that it happened, absolutely, but it seems to have been a freak occurrence. Perhaps in the future it will become common, but as of right now, you're the only person who's reported such findings. It's strange, especially considering that was nearly a decade ago and I haven't heard of any other cases since.
Anything's possible, but I feel with these things, you've got to distinguish a rare occurrence from something that happens all the time and needs to 100% be dealt with ASAP on any G4. It certainly isn't "just as likely" as 89-94 systems are, that just isn't right. Every single SE/30 with leaky caps vs. one G4 that did it isn't just as likely.

In the end though, stuff like that freak occurrence is why I'm going through and recapping anything that's reached an advanced age. Just don't want to risk it, because stuff like that can happen.

 

[volvo242gt]

The board that CircuitBored posted is another. I suspect we're going to see it more on the machines that were used a lot than on the machines that were used occasionally. My statement still stands, since even those machines that only saw occasional use will develop bad capacitors sometime in their life.

 

[3lectr1cPPC]

I'm unsure about CircuitBoard's board. That white stuff on the cap is the main thing - I've never seen a failure like that before, in images or otherwise. It looks most similar to what caps will look like after a battery bomb has gone off nearby, which suggests to me that some sort of external force has caused external corrosion, possibly causing the cap to leak later on. In the end though I'd need more details, such as if any liquid electrolyte was present, if the fish smell was there, and what the condition of other exposed metal parts on the board was. I do see what appears to be some green corrosion on the shell of one of the crystals in the photo - it's possible that that board was exposed to something, such as possibly very very high humidity for a very very long time.

I suppose in the end we'll have to wait and see what this era of caps do in the end. I'm not waiting myself though, my Sawtooth is getting recapped when I get the chance.