Classic II Corrosion: Am I Screwed?

not enough to matter. ive gotten TVs running with corrosion on the main CPU thats MUCH worse than that. your problem is toasted caps. they all need replaced before further diagnosis can be done.

not enough to matter. ive gotten TVs running with corrosion on the main CPU thats MUCH worse than that. your problem is toasted caps. they all need replaced before further diagnosis can be done.

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Sa-weet! I was a bit concerned when a trip through the dishwasher didn't clean up that corrosion much at all & didn't want to get it recapped if the corrosion is a fatal problem anyway. But it sounds like I'll be enlisting the aid of trag and/or phreakout!

Anyone else have more stories of Macs pluggin' right along with corrosion like this?

I would call that "gunk" sitting to the back (under the chip) and in between those pins, rather than "corrosion." That gunk could consist of a variety of things, including leaked capacitor fluid which you were able to clean off outside the chip but not underneath. I've seen this gunk before in my own experience. What I do is take a very tiny ice-pick shaped metal tool (about the thickness and shape of a wooden toothpick) and ever-so-slightly scrape in between each pin of such IC's, far back enough under the chip to ensure that no two pins are directly connected together by the gunk. (For chips that have a very tight pin spacing, I sometimes use an XACTO knife -- but such requires even more skill that metal pick, since you don't want to cut into your board -- just scrape away the gunk!) The gunk is not likely causing an electrical short between the pins that would fry the chip, but stray capacitance is a concern especially since some of that gunk is spilled capacitor fluid. So I would advise you to carefully scrape it away between each pin.

Before you scrape though, be sure you've don't your best to clean it off with alcohol outside the chip. I use a toothbrush and electronics grade dehydrated Ethanol for that task. That combination works so well to solidify the gunk that I don't have to do much scraping at all to clean the gunk away between the chip pins.

Lastly, I've read stories from many people here who merely clean the board and expect it to work like new. Yes, that does give the appearance of "restored operation" for a time on some boards, but the fact is, leaked fluid means your caps are either dead or at a diminished capacity. In any case, they all need to be replaced. Do not expect your machine to work properly until you do that. And yes, I am fully aware it is not a fun or quick job. But it is a necessary one.

Just curious: What is the lifespan of a capacitor? How much do storage conditions matter in their lifespan? Just curious. My oldest machine at this point is a Classic II that appears to still be going strong...also several Powerbook 150s...

Depends on the type. What we typically see failing and leaking are electrolytic capacitors.

Recapping Classic II boards is a pain because of the way they are spaced close to other parts (which also means the leaking goo will get into other important areas and make a mess). Most likely a recapping will give you video again, and hopefully nothing else is wrong.

As far as capacitors that leak, it is mostly the surface mount ones that do. I have yet to have to replace any of the other analytics on motherboards.

While it does depend on the environment (especially heat) and hours in use, we are talking about vintage Macs here. Simply put, expect the fluid filled electrolytics to last 15 years before they start to noticeably degrade in your vintage computers. Solid tantalum caps or the ceramic chip capacitors used all over the logic board will last as long as the logic board (60 years?). And while it is true that the tiny SMD type electrolytics tend to leak more visibly, the fact remains that non-SMD electrolytics also leak or otherwise experience diminished capacity after more than a decade of service. That is why when I recap my SE/30 logic boards, I take the time to also replace the two large axial caps as well. Anything less than a full cap replacement is not a complete job. And an incomplete job may result in unexpected operation from time to time.

I agree with JDW. Replacing all of the SMD caps with tantalum-type along with all axial-lead electrolytic caps will help extend the life of that logic board. Crickett, send me a PM if you'd like me to do some recap work. Get a hold of Trag, should you need to order replacement parts.

73s de Phreakout. :rambo:

Is there anyway to replace the axial lead caps with something that can't leak?

I have never seen an axial lead capacitor leak.

Recapping Classic II boards is a pain because of the way they are spaced close to other parts ...it is mostly the surface mount ones that do.

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This brings up an interesting question. By today's standards, there is really no point in owning a Classic II for any real work. It is essentially a stunted SE/30, which has neither the same power or capacity. Both it and it's sister Classic were giant steps backward.

So the question is, besides the form factor, is there any reason not to just get an SE or SE/30 and relegate the Classic series to the history books? The SE series was the last of the easy to repair compacts, and for the trouble the Classics cause, I'm thinking the last best EOL for the compacts to maintain modern functionality.

Whether the dissipated electrolyte can be seen or not (it is usually not seen), it is a fact that heat slowly degrades and dissipates the fluid over time. This occurs more rapidly on smaller sized capacitors, of course. And keep in mind that a capacitor may give a correct capacitance reading and still fail in-circuit due to its increased ESR rating. ESR speaks of the "resistance" rating of the capacitor in series while in the circuit. ESR Meters exist to test this value, even while the capacitor is in-circuit. An extremely high ESR value could cause the capacitor to rupture at some point.

Suffice it to say, whether you see the aging effects or not, you should replace all the capacitors, including the big electrolytics. It's been about 20 years on a lot of these compact Macs, folks. It's time to change those caps. (And yes, there are such caps even on the 128k logic board too!) With regard to the SE/30, the kit I purchased from Trag (at a very economical price) included both axial caps on the logic board. I did the job myself, but some on our last such as phreakout offer to do the job for a nominal fee. Unless you are skilled at the job, it would be worth it to pay to have the job done professionally. And it's not like you have to do this every few years. Once the main SMD caps are swapped out for tantalum versions, there will be a relative few fluid filled caps. And since those fluid filled caps are all the large sizes, I doubt you will need to swap them out again for at least another 15-20 years. Perhaps by then, assuming you are still around then, there will be a non fluid-filled version available to replace them.

Lastly, I agree with Mac128. I think the Classic's plastic case is a bit more spiffy than the SE and SE/30 series, but except for that, the SE/30 is better all around.

I had a Classic II but got rid of it. I prefer the SE , SE FDHD, and SE/30 models I still have. For one thing you have expansion options in the SE line, 3 of 4 compacts I own have ethernet.

Are there are caps on the analog board that one should consider replacing as well even if they aren't leaking at this point in time?

I love my Classic II for purely sentimental reasons.

Most of the analog board caps are of the larger size variety, and as a result, most of the time you can get away with good system operating without swapping them out. My SE/30 has new logic board caps but I never spent the time to replace the analog board caps. A lot of the bit analog board caps are very big and over-spec'd which is why your system still works even though the capacity has diminished through the years.

If you want to be thorough and have the best electrical functionality possible, then yes, by all means, replace all the caps on the analog board too. But once you start on a job like that, then the next logical step is to also swap out the electrolytic tanks in the PSU (power supply) too. And for an SE/30 power supply, that would be a real time consumer!

not to mention very expensive on some of those caps.

but WARNING. you cant just go out and replace your caps with just any caps, need to do some research on the known "good" capacitor companies. as alot of caps these days are chinese junk that will fail sooner and more destructively in a shorter timespan than what your leaking cap already is in its current state.

This brings up an interesting question. By today's standards, there is really no point in owning a Classic II for any real work. It is essentially a stunted SE/30, which has neither the same power or capacity. Both it and it's sister Classic were giant steps backward.
So the question is, besides the form factor, is there any reason not to just get an SE or SE/30 and relegate the Classic series to the history books? The SE series was the last of the easy to repair compacts, and for the trouble the Classics cause, I'm thinking the last best EOL for the compacts to maintain modern functionality.

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Lastly, I agree with Mac128. I think the Classic's plastic case is a bit more spiffy than the SE and SE/30 series, but except for that, the SE/30 is better all around.

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Y'know, that's pretty much my exact line of thought regarding these old compacts. I was (am) looking for a decent SE/30 as my primary compact, but the Classic II was a great deal (at the time) & was always my second choice. I greatly prefer the look of the Classic/Classic II cases, but functionally they clearly don't compare to an SE or SE/30. So that begs the question: has anyone tried putting an SE or SE/30 in a Classic case?

I know the back ports don't 100% line up, an SE/30 back bucket probably wouldn't fit on a Classic front (on account of the Classic's slight curve), a Classic's analog board might not power/fit an SE/30 logic board, but I can't imagine that a moderate amount of modification wouldn't result in a decent SE/30-powered Classic. Has anyone tried/succeeded doin' this?

It is essentially a stunted SE/30, which has neither the same power or capacity. Both it and it's sister Classic were giant steps backward.

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Actually not directly. You can think of it like this:

The Classic II was based on the 68030-based LC II that was designed to fit in a Classic case.

The SE/30 was based on the 68030-based IIx (actually more like the IIcx) that was designed to fit in a SE case.

The LC II was a 68030-based upgrade to the 68020-based LC (that was actually released after the Classic II, but all LC II added besides 68030 that was not in Classic II was 4 MB soldered RAM because by then Apple finally realised 2 MB was not enough for System 7).

The IIx similarly was a 68030-based upgrade to the original 68020-based II.

yuhong, I meant it's stunted in the sense that it did not improve on the SE/30, or the SE. Both Classics lowered the bar of what was expected from a Compact Mac.

Crickett, yes, I have powered every Compact Mac with every other compact Mac. Never for long periods, but simple mods in the power connectors allowed them to power on and function normally. But much more than a simple mod is needed to fit an SE/30 logicboard into a Classic case, as the logicboard is twice as big as the Classic logicboards. And two other major problems are the screen brightness control and sound as well as rear bucket ports.

I have put an entire SE chassis inside a Classic case, but the problem there is of course the rear ports need to be modified, which is easy enough to do, since the Classic's are higher, a new row can just be cut beneath them. In fact all of the compact chassis will fit inside all of the other Macs.

Crickett, yes, I have powered every Compact Mac with every other compact Mac. Never for long periods, but simple mods in the power connectors allowed them to power on and function normally. But much more than a simple mod is needed to fit an SE/30 logicboard into a Classic case, as the logicboard is twice as big as the Classic logicboards. And two other major problems are the screen brightness control and sound as well as rear bucket ports.
I have put an entire SE chassis inside a Classic case, but the problem there is of course the rear ports need to be modified, which is easy enough to do, since the Classic's are higher, a new row can just be cut beneath them. In fact all of the compact chassis will fit inside all of the other Macs.

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Eeenteresting indeed . . . I shall have to search specs & compare the SE/30 PSU to the Classic II's to get an idea about powering an SE/30 via Classic PSU long-term.

I know the Classic's are a half-depth board, but I think I could remove/relocate the fan (a la http://myoldmac.net/share/RC07/MacClassicII_256grayscale.php) to make room for a full-depth board & keep the C2 chassis & bucket.

The reason Apple built the Classic line of Macintoshes was to corner the market on computers costing less than $1,500 USD. The problem with doing that is you end up releasing hardware with less performance gain for the price. The Macintosh Classic I cost $999 to $1500 USD, had an 8 Mhz 68000 processor and up to 4 MB RAM supported. The Macintosh Classic II cost $1900 USD, had a 16 Mhz 68030 processor and up to 10 MB RAM supported. Compare that to an SE/SE FDHD costing $2898 and $3900, had an 8 Mhz 68000 processor and up to 4 MB RAM supported. And let's not forget the SE/30 costing $6500, had a 16 Mhz 68030 processor and can support up to an unbelieveable 128 MB RAM (unbelieveable by 1989 standards, of course).

Despite all these machines having the same processors (SE/SE FDHD vs. Classic and SE/30 vs. Classic II), the Classic I and II series were much slower. Here are some excerpts from MacWorld's Mac Secrets, 5th Edition by David Pogue and Joseph Schorr:

Macintosh Classic

After releasing increasingly faster and more powerful computers for several years, Apple released a cheaper, more basic compact Classic model, based on the slower 68000 microprocessor, in October 1990. Why this step backward? Apple was attempting to create a truly competitively priced computer, one that would be especially attractive to new users. The stripped-down Classic without a hard drive listed for about $1,000—a new low in complete-Mac-system pricing that would stand unchallenged for nearly a decade.

The modest price also meant modest equipment. The Classic was only 25 percent faster than the Mac Plus released more than four years earlier. The limited processing power outdated the Classic quickly; it was discontinued less than two years later and replaced by the more powerful Classic II.

Macintosh Classic II (Performa 200)

The Classic II, also marketed as the Performa 200, was the last of the original compact Macs. It runs twice as fast as the Classic and includes a connector for an optional math coprocessor. Unlike the Classic, the Classic II has a microphone jack for sound input.

The Classic II is newer than the SE/30, which it replaced in October 1991. To the chagrin of Mac users who loved the SE/30, however, the Classic II handles most processing jobs about 30 percent slower,even though it’s equipped with the same microprocessor. What accounts for the difference? The data path.

The Classic II is equipped with only a 16-bit data path between the ’030 processor and the RAM chips, whereas the SE/30 provides a 32-bit data path. In other words, the Classic II can move only halfas much data at one time between the computer’s memory and central processor as the SE/30.

When the Classic II was released, it cost about $1,000 less than an SE/30 (which at the time was selling for more than $3,000), making it a good deal despite the slower speed.

73s de Phreakout. :rambo:

(Performa 200)

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woot!

phreakout, thanks for the history lesson, but I'm not sure I understand why you posted it. It's also wrong. The Classic and Classic II overlapped by one full year, the Classic II did not replace the Classic, no more than the SE/30 replaced the SE. You could have saved yourself some trouble and just posted links to many other sites that would have been more accurate. :beige:

It seems to me the Classic series' step-backward here was not in question from a business standpoint but rather, the chagrin of the customers who still loved the form-factor, who were unwilling to accept less than what they had. Whatever the reason Apple did what they did, there is no reason to settle for less today than an SE or SE/30, which was the high-mark for the compact Mac. Price is no longer a significant issue. Style on the other hand is an issue, and then as now, Apple was counting on it to help move units.

And on the original Classic, it was to finally replace the Plus from 1986, which was the last Mac still produced that still use the 800K floppy and the old keyboard/mouse interface dating back to the Mac 128K. While the Mac Classic is indeed less expandable than the SE, it still include many of the enhancements from the SE, such as the ADB keyboard/mouse interface, better SCSI, a newer ROM than in the Plus, and support for an internal hard drive, and more.

And on the original Classic, it was to finally replace the Plus from 1986

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Yes, and on that front it was absolutely a step up. However, it left a gaping hole where the SE was, and I believe it actually ran slower than the older technology.

In addition, a year later, System 7.0.1 was released, arguably the highest system useable on the Classic. It also shipped with only 1MB RAM. Anybody who tried to get by with that small amount too long for the entry price, found themselves out of luck if they needed to upgrade since it required a non-standard RAM board, whereas a Plus and SE could keep adding years past their discontinuation without any special attachments. Apple sold it as an upgradable computer, but once users upgraded it to a usable condition, they might as well have bought an LC.

Apple had to redesign the logicboard anyway. Why they wouldn't take the 16MHz bus used on the Portable and put it in the Classic at the same price point is beyond me – at a minimum, they should have offered it as an option. As it is, there was no trade off, just a step backward. I don't buy the 1.4MB drive as an upgrade feature, it had been around for 2 years at that point, and actually saved them money not to have buy obsolete 800K drives, or support them. One of the reasons I hate the Classic so much is because so many schools who had been so well served by Apple over the years, bought tons of Classics without knowing how antiquated they really were and found themselves with useless equipment just a year later, with payments still to be made on them. That's the day Apple lost to the PC, when parents started having better technology at home than the kids had at school.

It also shipped with only 1MB RAM. Anybody who tried to get by with that small amount too long for the entry price, found themselves out of luck if they needed to upgrade since it required a non-standard RAM board

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Yea, that entry level config also didn't have any hard drive built-in and was simply to replace the Plus period at a lower price, which I am sure tempted many buyers. Because of the lack of these two things, it was not ready for System 7 out of the box which was released 6 months after the Classic! There was a better more expensive config with that non-standard RAM board already installed resulting in 2MB of RAM and a 40MB hard drive installed too that was ready for System 7 (which needed both of these things) and you could then get 2 standard 1MB SIMMs and install it on the non-standard RAM board later, resulting in 4MB of RAM which was the max.

don't buy the 1.4MB drive as an upgrade feature, it had been around for 2 years at that point, and actually saved them money not to have buy obsolete 800K drives, or support them.

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Yea, I did say that the Mac Plus "was the last Mac still produced that still use the 800K floppy and the old keyboard/mouse interface dating back to the Mac 128K". In fact, I think that the Mac Plus was the biggest barrier to the death of the 800K GCR floppy for years.

However, it left a gaping hole where the SE was, and I believe it actually ran slower than the older technology.

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I think it ran at the same speed at the SE, which was slightly faster than the Plus, owning to changes in the video and RAM refresh.

Sorry about posting the history lesson. I was trying to show that despite the Classic I and II being the successor to the Plus, SE/SE FDHD and SE/30, the latter isn't as stripped down for use. I still would use my SE/30 over a Classic II any day.

Keep in mind that the tidbits from Mac Secrets was written some time in 1998/1999, so the info is a bit dated. But still, you can't give credit where it's due, and David Pogue did a good job writing that series. I relearned a lot of stuff I could have easily missed out on. That, plus the fact that no links exist that I've searched around for, contain PDFs of the books to reference from. So I did the next best thing and pulled it out of my own copy.

Correct. Price is not as significant an issue compared to then. But I think we can all agree that the machine we want to buy is capable of doing what it needs to do and in the least amount of time. Sadly, I was too poor to afford a computer when they became available in the 80s and 90s, but waiting almost 15 to 20 years after that machine's creation allows you that luxury.

73s de Phreakout. :rambo: