Recycled Classic — worth persevering with?

[scruss]

I picked up a Macintosh Classic at an electronic waste roundup the other week. Despite the case being badly discoloured and giving a RAM-related Sad Mac on boot, I could tell that the Quantum HD was still spinning and the display is really sharp.

The machine has its problems, and I'm wondering if it's worth refurbing. Your advice/opinions on the following are welcomed:

• Capacitors — I recapped the logic board and replaced the PRAM battery. The logic board caps had all leaked, and cleaning up the mess was not fun. The battery, though dead, hadn't leaked.
• The Fishy Smell — The analogue board looks clean, and the display is steady and sharp. The machine still smells pretty rancid when it warms up, though. I thought I'd cleaned all of the capacitor goo off the logic board (even the stuff crusted under the SCSI controller), but maybe the smell is some left over.
• Floppy Drive — the SuperDrive doesn't recognize formatted disks. If you let it format one, it clicks through all 80 tracks formatting, then verifies, then reverifies, then spits the disk out with an error. I haven't cleaned the heads or done any of the lubrication tricks yet.
• RAM — the two 30 pin SIMMs on the daughtercard don't seem to be recognized, so unless I set the jumper to “SIMM not present”, I get the Sad Mac. I tried alternative SIMMs from a local salvage place, but got mostly the same errors. As is, I'm stuck with 2 MB until I work out what's up. Do these daughtercards ever fail?
• Case — cosmetically horrid, with yellow discoloration on the main case and keyboard.

So display, hard drive (completely with slightly messed-up 7.1 installation), keyboard and mouse are fine. I realise that an 8 MHz 68000 ain't all that, so I'm wondering if further work on this is worth the effort.

 

[EvilCapitalist]

It sounds like you're well on your way and given the work you've already done it's a machine worth saving.

As far as the floppy drive and RAM daughtercard not working, it wouldn't be the first time that a floppy drive appeared to work but didn't, ditto for the daughtercard.  If cleaning/lubricating the floppy drive doesn't get it working properly, replacement drives are cheap and plentiful.  The daughtercard may have succumbed to static electricity (I lost a ROM SIMM that way) or it could have taken a hit when the caps leaked originally.  They pop up for sale somewhat regularly and if you can't find one there's probably someone on here with a bunch who'd be willing to part with one.

The case is probably the most involved.  If you're going to retr0bright it there are a number of threads on here with solid instructions for doing so, though it's a lot of trial and error.

 

[MJ313]

The Classic AB caps are notorious for going bad. They may look fine, but underneath they are leaking (and stinking).

See here:

https://68kmla.org/forums/index.php?/topic/22550-powerbook-160-found-but-with-problem/?p=235503

 

[BadGoldEagle]

You definitely need to save it!

About your RAM issue: Since it works without any SIMMs connected, I'd say the SIMMs themselves are faulty. It's much easier to electronically damage chips on the SIMMs than traces on the daughterboard, especially since there are no battery or capacitor on that vertical board.

According to Larry Pina's Mac Classic & SE repair, you can use two-chip SIMMs, rated 100ns or faster. "You may also be able to use 100ns, 1M DIP SIMMS, provided they're no taller than 1 1/16 inches. Physically larger 1 5/16-inch, 1M DIP SIMMs tend not to fit the 30° socket."

Try replacing SIMMs, and see if it makes a difference. Do you have a 'full' Sad Mac error code? 

Sometimes, this happens:

 

[Elfen]

"All Macs Matter."

With that said, it is well worth it furbishing. I found a Classic II in the trash heap a couple of years ago and I got it up and running after getting the needed parts, and spending time cleaning and recapping. The Audio is gone (broken trace somewhere on the logic board), but that is fine with me as I use it for visual things and not audio things.

My adventures of that is somewhere in the Classic Mac Forum Threads in Summer 2014 or so.

 

[tanaquil]

The floppy drive sounds like it might need a head cleaning. I have a floppy disk (actually several!) for the purpose and little bottles of solution, and I have to clean heads all the time. I expect you can clean the heads by hand but I don't trust myself not to break something. Relubing is always good, but is more likely to fix ejection problems than reading problems.

RAM: Have you tried cleaning the contacts on the daughterboard? Or, as others have said, the daughterboards are pretty commonly available, often with the extra RAM included. If testing the SIMMs, make sure you try some known good SIMMs, since the ones from the salvage place might be bad if you haven't tested them elsewhere.

Good luck! I have all the parts I need now to rebuild my old Mac Classic that succumbed to a malevolent Maxell. Of course I have sentimental reasons for wanting to save that one (my first Mac), but I still think the Classic is a good machine worth saving.

 

[scruss]

Thanks, all. I'll source the replacement big caps for the analogue board today.

While I did clean the SIMM connections, I don't have any other machines to test 30 pin SIMMs with. Two and 8 chip SIMMs are rarer than hen's teeth around here; I can get any number of 3 or 9 chip ones. The 70 ns ones I tried (and returned) gave me the split Sad Mac as shown above. Maybe I'd be better off with a whole new daughtercard.

Will definitely clean the floppy drive, once I work out how.

 

[BadGoldEagle]

Keep in mind that anything faster than 100ns won't work, so 70ns was never gonna work. 120ns SIMMs are recommanded.

9 chip SIMMs 'should' work, as long as the speed rating is correct for this machine.

Good luck! I've always liked the Mac Classic's looks. It's really nice bringing an old mac back to life!

Edit: typo

 

[scruss]

Great! I got the floppy working with a $2 (thanks, Above All Surplus!) drive cleaning kit.

 

[yuhong]

Keep in mind that anything faster than 100ns won't work, so 70ns was never gonna work. 120ns SIMMs are recommanded.

That is not how DRAM generally works. In fact, I think 80ns was the most common DRAM when the Mac Classic was new.

And yes it is possible that the 1Mbit DRAM chips on the daughterboard itself may be bad.

 

[scruss]

Just as a summary to all this, I've given up on this Classic. There's a trace corroded through on the logic board that is stopping all of the RAM appearing. A complete swap of the memory daughter card made no difference. The display board caps are shot, too. Although the display is solid, it starts to stink as it warms up.

I've decided to keep the replacement display caps for the near-pristine Classic II I scored from a friend. I just recapped its logic board, upped the RAM and replaced the battery, and it runs really well. I'm glad the Classic II works with the BMOW Floppy Emu, as now I have some removable storage.

 

[techknight]

Well I would hang onto the Classic's CRT, I keep a couple CRTs around because you never know Especially if one is super burned in you can swap it out, or if you conquest another machine and the CRT was broken in shipping so you can swap that way. 

I also have a spare color classic CRT on hand for this very reason. 

 

[just.in.time]

My trusty SE FDHD has quite the burn in, with the "You may now turn off your Macintosh" dialog, complete with Restart button forever etched in.  Not the end of the world, but oh well.  It was like that when I got it over a decade ago.

Edited to add:  Which version of the System software had the restart button on the left side of that dialog?  System 6.0.8 through 7.5.3 appear to place it on the right hand side.  Never have personally run lower than 6.0.8 on that particular machine.

Techknight, I too have a spare color classic CRT... that is damaged and has shifted colors, presumably from the shadow mask shifting  :O (from my thread a few months ago)

 

[BlueBoy]

Edited to add:  Which version of the System software had the restart button on the left side of that dialog?  System 6.0.8 through 7.5.3 appear to place it on the right hand side.  Never have personally run lower than 6.0.8 on that particular machine.

Your question made me curious so I fired up Mini vMac. I have a bunch of disk images with many system versions from early to late. System Software 2.0 (System Version 4.0, Finder 5.4) introduced the separate "Restart" and "Shutdown" menu items in the "Special" menu. Choosing "Shutdown" on Macs without soft-power (Mac Plus, SE, Classic, etc.) displays the black screen with "It is now safe..." dialog. Starting in System Software 2.0 the "Restart" button is on the left.

The "Restart" button remained on the left through the System Software 5 family (System Software 5 series came right after 2)

and from System Software 6.0 - System Software 6.0.5. System Software 6.0.6 was never publicly released due to a bug.

By System Software 6.0.8 the "Restart" button had moved to the right of the dialog.

Unfortunately, I don't have a copy of System Software 6.0.7 to test.

 

[just.in.time]

Good to know thanks for checking on that.