Macintosh SE Troubleshooting

[dcr]

After "marrying" two partial SEs to form one complete machine, I am now trying to troubleshoot the result.

It powers up but there is no startup chime and the screen is a checkerboard pattern. In searching for a solution, one suggestion I found was to remove the RAM and ROM, clean the connections and re-install. I don't have a tool for removing the ROMs, but I did remove, clean and re-install the RAM. It didn't make a difference.

One possibility is that the ROM connections need to be cleaned, but I am not sure how to remove them without an appropriate tool. For what it's worth, they look clean and are firmly seated.

Another possibility is that the RAM is bad. I don't have a working SE to pull RAM from to try. What other models would have comparable RAM? I do have an SE/30 that, until this afternoon when it decided to give out, was working and presumably has good RAM.

And, if it's not the RAM, what else could it be?

 

[bibilit]

Ram is the same on the SE/30, but keep in mind that you have a resistor to cut accordingly.

http://www.hardwaresecrets.com/inside-the-macintosh-se/5/

Another possibility is the PSU not producing the required output, but again the PSU from the SE/30 can be used, IIRC the board from the SE can be used in the SE/30 for a test.

 

[dcr]

Thanks.  I do have an SE/30 without a motherboard, so I could transfer the SE motherboard to it as a test.

Except the SE/30 has a 1.44 MB floppy drive and the SE is not the SE FDHD model so I don't know if that would work unless I also swap out the floppy drives.

 

[bibilit]

For a test, the floppy is not mandatory.

 

[dcr]

Didn't matter anyway, since I discovered the SE/30 is lacking a floppy drive as well as a motherboard.  No hard drive either.

But now I know the SE motherboard is good.

The analog board in the SE/30 is a Revision C analog board, which is the same as what the SE has.  The analog board, power supply and CRT were from a SE FDHD that had a rusty floppy drive and no motherboard.  So, I am going to do another "surgery" and remove the analog board, power supply and CRT that came from the SE FDHD and install the analog board, power supply and CRT from the SE/30.

And hope I end up with a functional Macintosh SE as a result.  Don't know if the hard drive will work but I'll find out.

 

[dcr]

I now have a semi-functional Macintosh SE.

Hard drive doesn't work.  I kind of expected that.

It won't boot from my System 6.0.8 floppy (800k disk).  I have been using that disk on several machines, so maybe it was damaged.  Booted up a Mac Plus that booted from the floppy the other day.  It started up but then said the Finder was corrupt.

So, I am now re-doing the floppy and will try again. . .

Okay, after somewhat of an ordeal getting a bootable 800k floppy again, the SE spits it out immediately.  The Mac Plus will boot from the disk, so I know the floppy is okay.  But the SE does not apparently like it at all.

 

[dcr]

I am beginning to think the only way I am going to get a working Macintosh SE is to buy a working Macintosh SE.

I tried a different floppy cable.  That made no difference.

I tried installing a different floppy drive.  That made no difference.

It could be that the floppy drive in the machine and the floppy drive I installed are both bad, as neither have been tested in anther machine.

Or it could be that something is wrong with the SE motherboard such that it won't recognize any floppy disks.

I have no idea.

I do know that the floppy disk works, as a Macintosh Plus boots from it just fine.  (Both before and after testing on the SE, just to make sure the SE didn't ruin the disk.)

And, right now, the original floppy drive in the SE won't eject disks, so I've messed something up with it somewhere.  Or, rather, I made it worse because while it wouldn't boot from the floppy disk before, it would at least eject it.

 

[bibilit]

try cleaning and servicing the floppy drive first, as those have a tendency to don't read disks, have a look at the Wiki for servicing.

 

[dcr]

If anything, I'm getting proficient at disassembling and reassembling a Macintosh SE.

Following the wiki instructions, I cleaned and lubricated the floppy drive then with the it appearing to be in good working order optimistically put everything back together . . . And it still won't read the floppy disk and it still cannot eject the disk. Had to resort to a paper clip to eject the floppy.

It may be time to declare it dead.

 

[DragonKid]

Not ejecting sounds like a bad drive to me, possibly a bad IWM chip (it's socketed, next to the 2 ROMs).  1.44MB drives will work in a non-FDHD SE, you just won't be able to read/write 1.44MB disks in it.  I had a 1.44 out of an LC in my SE for years and years until I needed a 1.44 for another machine, which finally motivated me to clean and lubricate the original 800K drive and put it back in the SE.  While you probably don't want to dismantle all your Macs, you could try this drive in the Mac Plus or try the Plus' drive in the SE.

 

[dcr]

To clarify, the floppy drive was able to eject disks until I cleaned and lubricated it which may mean I did something to cause that particular problem, but I cannot figure out what, since everything looks right and works properly if I manually work it.

At any rate, I finally had the time to sit down and give DragonKid's suggestion a try.  First, I booted up the Mac Plus to make sure its floppy drive worked and, more importantly, to make sure the boot floppy worked.  It did.  So, I removed the floppy from the Mac Plus and put it in the Mac SE.  With that floppy drive, the SE booted fine.  And I confirmed it has 4 MB RAM so yay! for that.

Which means the SE's floppy drive is the problematic one.  Are there any other things to try with it?  I went through cleaning and lubrication process described in the wiki, so if that doesn't work, is it basically dead?

Or do I just need to track down a working (hopefully) 800k floppy drive on eBay?  (I know a 1.44 MB floppy drive will work and I'll consider that as a last resort; I'd just prefer an actual 800k floppy drive to be more authentic.)

 

[CC_333]

When you try to eject, does the eject motor make a sound?

If not, maybe you forgot to plug the ejector motor's power connector back in?

If it is plugged in, and it's making noise, maybe it stripped a gear somehow.

Or, if it's plugged in and there's no noise, then the motor somehow died, OR the microswitch that tells it when to stop has gotten stuck.

c