Mac Plus screen repair

Hi all,

The same attic that contained my Powerbook Duo also contains a Mac Plus.

This computer has been in my attic for 10 years, I can hear it booting, but the screen is completely dead.

It has an external hard disk but is missing a mouse.

How likely is it that the screen problem is an easy fix like replacing a fuse or something? I don't have the skill to make a complex fix myself, and I don't want to spend a lot of money on it.

Thanks,

Daniel

Thanks!

I'll take a look and see if I can see anything.


D.

You're not gonna believe this - I gave it a good thump on the left-hand side, and it's been working ever since! The screen is a little smaller than it is supposed to be, I think, but it is stable.

I even mnanaged to get it to boot from it's 20-year-old hard disk, It says 20SC on the HD BTW, does that mean it's a 20MB disk?

There's not much you can do with it without a mouse, so the next thing is to get one.

I can hardly believe it ....

MacTech68 said:

Cool. Don't be surprised if the picture disappears suddenly.

Yup, 20SC is 20MB.

The mouse may be a little difficult. An old PC serial mouse will NOT work.

There's a few on eBay: http://www.ebay.com/sch/i.html?_nkw=mac+plus+mouse

The screen size is probably adjusted as per the specs in the service manual. The border was always quite large looking IMHO.

Click to expand...

Well, obviously the loose connection is still there,but this does mean that we know what the problem is, and that it's easily fixable. What I really couldn't believe was how everything still works after being junked and spending 10 years in my attic.

You tend to forget how slow the old disks were, and how noisy. When you run the old stuff in emulators it runs really fast .. . . .

Hi all,

My mouse arrived in the mail today, so I was able to use my Mac Plus for the first time. It came on OK, although it needed a little gentle persuasion to display the screen stably. Once it was stable, however, it stayed rock solid, and I'm really wondering whether it is worth getting it fixed - I have found someone who is willing to do it, but there is always the risk that he'll muck it up. I am thinking of waiting till it won't come on at all any more, and then getting it seen to; it's not as if I'm actually going to use it for anything, after all.

Anyway, here are some pictures that I thought you may find interesting.

It is interesting because the system is in Hebrew:

Here is the Mac in all its yellow and grimy glory. The mouse is brand new and a completely different color:



A menu in Microsoft Word with the key commands on the wrong side:



The finder version. What system is this?:



The control panel in Hebrew:



The Rav Ktav Hebrew word processor:



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One more picture - the startup screen. It says "Macintosh at your service"




PS. The diskette drive does NOT work...

Hi all,

Here are some more Mac Plus pics:

I've had the Mac apart to work on the floppy drive (and something is not working right, see separate thread). While I was in there I took some photos:

Grimy motherboard. I'd like to clean it up, but since it seems to work perfectly, I don't want to do something drastic like putting it in the dishwasher, Any suggestions as to how to clean it?



Inside the Mac, sans motherboard:



The analogue board:




The Mac with his wizkid grandson. Neither of these two Macs has a floppy drive, at the moment:



Finally, this Mac is running System 4.1. this is the oldest system I've ever used (except on emulations). Here is Switcher:

MacTech68 said:

Cool. Don't be surprised if the picture disappears suddenly.

Click to expand...

Hi,

I'm a little puzzled by this screen issue.

It's getting better. The screen always comes on. All that's left of the issue is a little shimmery effect when the machine is stone cold, that goes away as soon as it warms up. It even works when it's standing on top of the HD. At first the vibration made the screen flash like crazy.

Is it conceivable that the issue was not caused by a cracked solder, but by dirt and dust which I partially cleaned off when I dismantled the computer and which is gradually burning off as I use it?

I can't imagine that a cracked solder would gradually heal itself; I've certainly never seen similar issues get better in other devices that I own, like old electronic musical instruments.

EDIT: This Mac stood idle for nearly 20 years. I can find no evidence that it was use after 1994. It presumably stood for 10 years in an office at the university, and then since about 2004 in my attic.
This what killed the floppy; the amazing thing is that everything else works, including the old hard disk and the original keyboard.

Thanks.

It's definitely past time I learned how to solder. I've done electrical soldering in old cars, but nothing delicate like soldering in a computer.

D.

daniel-b said:

Thanks.

It's definitely past time I learned how to solder. I've done electrical soldering in old cars, but nothing delicate like soldering in a computer.

D.

Click to expand...

Hi all,

This afternoon I took a large dose of brave pills, and soldered the video pin on my Mac Plus's analog board. As far as I can see, it's now working perfectly The screen is stable and perfect.

Thus far I've only gone as far as the flashing disk icon.

Next step is to prepare a boot zip disk for it on my Quadra, and see if it can be an alternative to the large, noisy and heavy SC20 hard disk.

I am extremely chuffed . . . .

D.


PS. I have not yet replaced the cardboard on the analog board; I thought I might leave it off to see if it continues to work OK or if I need to do some more work. Is this a problem?

Edit: I got the Mac Plus to boot from the zip disk into System 6.0.8, and I got the Quadra to work with my 24" Samsung monitor. Wonders never cease . . .

Thanks.

I was going to use new double sided tape, which is why I was going to leave it off till I'm sure it's working OK (I was going to stick it on when I install the floppy drive, which I will be receiving soon).

The double sided tape tends to stay stuck once you stick it and I didn't want to have to take it off again any time soon.

D.

A couple of pictures:

My desk; three keyboards, three mice, two computers. Note the zip drive on top of the Mac PLus and System 7.6 on the 24" monitor:



THe Quadra is under the desk:

Hi all,

I just killed my Mac Plus

It became obvious to me that my previous soldering had not in fact solved anything, so I went in and soldered the rest of the power plug contacts. This went smoothly, with a new soldering iron.

When I turned it on it was still flickering, so I basically opened it up and then closed it again. When I plugged it in there was a loud pop and then silence.

I think what has happened is that a tiny drop of sweat fell unnoticed on the back of the analog board, and this killed it.

I retrieved a very black and dead fuse from the machine. What are the chances it might be revived? There is no visible (to me) damage and there was no smoke or smell of burning.

Needless to say I am pretty pissed off at myself for killing my computer in such a silly way after it survived my efforts at soldering it. It does seem that the soldering didn't help, so I am wondering what the problem was...

THanks,

Daniel

MacTech68 said:

Bummer. I feel really bad for you, (and a little responsible).

A little trick with glass fuses. If, when it blows, the inside of the glass is blackened and splattered, then there is a lot more wrong than just the fuse. Something has more than likely shorted. Replacing the fuse under these circumstances is likely to do more damage.

If you can see through the glass, and can see the ends of the fuse wire with a gap in the middle, generally, the fuse can be replaced.

Unfortunately, in your case, it seems that there is more damage here, and I am sorry that I suggested attempting to re-solder it (if indeed this caused the damage).

It is possible, that the work you did DID NOT cause the problem, as these analog boards were not known for their reliability.

Click to expand...

Hi,

Thanks for replying.

As I said before, I believe that what made the fuse blow is that the board got a drop of sweat on it. I do not think my work killed it. I do not however believe that my work fixed it either.

I think the drop of moisture caused a short. I cannot see any other signs of damage (if this means anything).

Thanks,

Daniel

MacTech68 said:

Bummer. I feel really bad for you, (and a little responsible).

Click to expand...

Don't. I blew the damn computer up, not you.

Here are some pics. I do have a multi-meter, and I know how to use it. I once rewired an entire car.

The card was in when it blew. Here is what it shows.


The marks in the circle are new, and they correspond to where the analog got wet. The rest were already there before.

Here is the analog board at the area corresponding to the new mark:



Perhaps more interesting, here is the area corresponding to the old black marks:



Finally, for what it's worth, here is my soldering work:





Ideally, I would like to get this machine going, but if I've killed it, then I will view it as a learning experience.

Thanks for all your help,

Daniel