Macintosh Plus - Unknown CRT Problem

[HunterCupp]

MacTech68

I have resoldered the joints from which you advised and powered on my Macintosh Plus. There was no change as far as I am aware. Everything is exactly the same so far. As I was soldering with a 30W soldering iron I had purchased from RadioShack, I had noticed that my soldering spots looked different from the rest, they looked wrinkled and rough, not shiny and smooth like the others, but I will assume this is because it isn't new solder and it is just reheated.

I am going to attempt at a second go before stopping with soldering for the night. Hopefully you can reply soon. I will post pictures within the hour.

-Hunter

 

[HunterCupp]

MacTech68 and tdiaz

Here are the pictures of my soldering. Unfortunately it did not fix the issue.

-Hunter

 

[MacTech68]

Doesn't look that bad!

From here things get petty complicated - sadly. Unless anybody has seen this exact issue and knows the fault, I'm going to say it's guess-work via forum.

Did you happen to have a multi-meter?

 

[HunterCupp]

MacTech68

I do not believe that I currently own a Multi-Meter. Why do you ask? I will assume that you wish for me to measure the voltage going into the CRT from the metal rods inside of the suction cup thing?

-Hunter

 

[MacTech68]

MacTech68

I do not believe that I currently own a Multi-Meter. Why do you ask? I will assume that you wish for me to measure the voltage going into the CRT from the metal rods inside of the suction cup thing?

-Hunter

No. Certainly not! Never contemplate anything like that. There is special equipment for doing so, but in this case, that is not neccessary.

I am going to suggest checking a few resistors and diodes with the unit un-powered, and a few of the low voltage rails like 5V and 12V.

 

[HunterCupp]

MacTech68

Just give me directions and I'll see what I can do. I'm ready for anything at this point.

-Hunter

 

[HereBeMonsters]

MacTech68

Just give me directions and I'll see what I can do. I'm ready for anything at this point.

-Hunter

Just don't test anything with it plugged in for now - CRTs have massive voltage steppers that won't just give you a nasty shock, but could very easily kill you.

 

[HunterCupp]

Just don't test anything with it plugged in for now - CRTs have massive voltage steppers that won't just give you a nasty shock, but could very easily kill you.

HereBeMonsters

I am very aware of the amount of electricity within the Macintosh and the dangers of testing without the CRT being discharged and taking other precautions such as unplugging the Macintosh, taking out the battery, and leaving it sit for a couple hours. I thank you for your concern.

-Hunter

 

[HereBeMonsters]

HereBeMonsters

I am very aware of the amount of electricity within the Macintosh and the dangers of testing without the CRT being discharged and taking other precautions such as unplugging the Macintosh, taking out the battery, and leaving it sit for a couple hours. I thank you for your concern.

-Hunter

No need to be sarky. Just when you said you were going to roam around the CRT connections with a multi-meter, that can be concerning!

Just as long as you know - I've been fixing cars with people before, and they've done ridiculous things like unplugging HT leads with the ignition on. Previously bright people, who I think were planning on living a while longer...

 

[HunterCupp]

No need to be sarky. Just when you said you were going to roam around the CRT connections with a multi-meter, that can be concerning!

Just as long as you know - I've been fixing cars with people before, and they've done ridiculous things like unplugging HT leads with the ignition on. Previously bright people, who I think were planning on living a while longer...

HereBeMonsters

I think you may have misunderstood me to be sarcastic. I was dead serious about being thankful for you mentioning the safety hazard and being concerned. It makes me happy to see people on here who care and mention these things. So thanks, again.

-Hunter

 

[tdiaz]

Trust me.
taking out the battery is going to have -ZERO- to do with it, as would be leaving it unplugged "for a while".

I've measured discharge on CRTs that have been sitting off for years, and I've measured no discharge on CRTs that have been off for just a few minutes.

There is no method of discharge inherent to the design. It's purely environmental.

The only thing consistent is, you should -always- consider a CRT live, and always discharge it before doing any kind of un-powered servicing.

That said, short of having a HV probe for your meter, or integrated probe, you're not going to be measuring anything having to do with the business end of that flyback with the typical meter.

http://www.amazon.com/Precision-HV44A-Voltage-Probe-Meter/dp/B000LDFNF8

How to discharge an Arcade Monitor (or any other)
http://www.stickycarpet.com/pinx/md.html

The soldering looks good for all intents, solid connection, no cracks, nothing moving. Component fully inserted into the board.

Gotta find the book with the symptoms/components listed.. IT's been quite a while since I was exposed to fixing them daily.

 

[MacTech68]

...I've measured discharge on CRTs that have been sitting off for years...

Yup, I experienced that on a 23" tube that had been sitting for several weeks out of it's cabinet disconnected from EVERYTHING, having been discharged several weeks earlier.

I'll be looking over the circuit and responding soon. Let me know when you have that multimeter.

BTW, there's still no guarantee this can be fixed via forum.

 

[HunterCupp]

To Everyone...

Not to make anyone sad by this decision, but I've decided that I am going to leave the CRT alone in its current state. I feel that moving on further will only cause damage to the computer. I have problems putting the case back together and have started to see small cracks on the inside of the case that surrounds the CRT and have become worried about taking it apart any further. I have one last request. My floppy disk has come in today, on the floppy, it reads "Disk Tools - Macintosh". Is this the correct floppy, as I had purchased a System 7.1 boot disk. I have also come to a problem in which after the first boot with the disk (everything seems functional). When I instert the floppy into the Macintosh, it will show the Macintosh icon with the smiley face, and then eject the floppy. I can't get it to boot with the floppy anymore and am unsure of why. Can anyone help?

I thank everyone who has helped me so far and am extremely thankful for all of your assistance. Even though the issue was not fully resolved, I still couldn't have asked for a better team of people throughout the world to help me in my time of need.

Once again, thank you all.

-Hunter

 

[MacTech68]

I have the greatest respect for your decision to halt where it's at. No problem there.

At least we've re-soldered the more common dry joints.

Regarding the the floppy, it could be that the heads have become dirty. If you can find a 3.5" floppy drive cleaning diskette, you could try that. Anything else will most likely require stripping the drive.

 

[HunterCupp]

I have the greatest respect for your decision to halt where it's at. No problem there.

At least we've re-soldered the more common dry joints.

Regarding the the floppy, it could be that the heads have become dirty. If you can find a 3.5" floppy drive cleaning diskette, you could try that. Anything else will most likely require stripping the drive.

MacTech68

I find that odd considering that it worked perfectly before it's second boot. Are there any other leads to the reason of why it would automatically eject before boot?

-Hunter

 

[tdiaz]

It ejects before boot because it can't read anything useful on the disk.

As for drive heads getting to that point, yes. One disk worked, the next one doesn't.

Just one nanospec of crap too many on the head.

Ever snow roller starts with just one flake.
Every sand dune starts with one grain.

Sooner or later, something gives.

Cracks in the case from opening it, kinda shocks me. They're simply not that fragile, unless the environment has done one particular case in, and after having some that have been out in the yard since Kuwait was invaded, and are still pliable, and survivable, I'd be pretty surprised if handling it just did that.

As for the difficulty in opening/closing them- they're generally not "easy" anyway.

The way I see it, deal with everything while it's apart, and be done with it. Equally, though, I can certainly respect the decisions based on the unknown or lack of experience in working with them over the years. No worries.

But on that floppy drive, it could also be to the point where it will require intervention that means getting into the unit, too.

 

[HunterCupp]

It ejects before boot because it can't read anything useful on the disk.

As for drive heads getting to that point, yes. One disk worked, the next one doesn't.

Just one nanospec of crap too many on the head.

Ever snow roller starts with just one flake.
Every sand dune starts with one grain.

Sooner or later, something gives.

Cracks in the case from opening it, kinda shocks me. They're simply not that fragile, unless the environment has done one particular case in, and after having some that have been out in the yard since Kuwait was invaded, and are still pliable, and survivable, I'd be pretty surprised if handling it just did that.

As for the difficulty in opening/closing them- they're generally not "easy" anyway.

The way I see it, deal with everything while it's apart, and be done with it. Equally, though, I can certainly respect the decisions based on the unknown or lack of experience in working with them over the years. No worries.

But on that floppy drive, it could also be to the point where it will require intervention that means getting into the unit, too.

tdiaz

Alright, anything I can do will be effective I suppose. What exactly do I need to do for the Floppy Drive? I'd rather get everything done in one go rather then doing one part, putting the case back on after 15 minutes of struggling because it doesn't want to fit properly and doing the next a few hours later. Just a refresher of my problem because I'm running out of things to say and still want to seem professional. I have one floppy disk, brand new, of System 7.1 and it's tools. I put it in for a first boot, it works fine. Having done what I needed to do to make sure the drive still worked, I turned it off. About an hour later, I turned the Macintosh on (The floppy was still inside) it displayed the Macintosh symbol showing that it was looking for an OS/Boot Disk, then it ejected the floppy before it could boot, and it's been doing that ever since, on the same floppy (I only have 1.)

EDIT: I've bought a Drive Head Cleaning Kit on eBay to try out on the Mac first off. It should be here on or before Friday. If you have any other suggestions, I would appreciate them as well.

-Hunter

 

[tdiaz]

Unless you have a cat, you don't need to have the back on the computer when your not using it, or can just slide it in.

I feel really good about claiming that you can't possibly break it trying to slide it off and on. They are -tight- to put on all the way. To get them off I usually do a slap and lift where it's face down on a sofa like surface, and in a motion like clapping symbols, my hands come together in a swooshing motion with an upward moving lift just as I'm making contact with the sides.

I do that a couple times, then put palms on the sides with thumbs over the mouse and serial port areas and squeeze palms while applying pressure to the exposed connectors to make the case rear slide up. Most of the time that opens it, if not I similar movement while pressing on the power switch or battery.

If that plastic case is really that brittle that it's cracking, you'd be seeing pieces falling off when you tried to open it. They really are quite sturdy, unless that one was sitting in a rotten hot, unbearable for a human, environment for years on end. It just does not look like that at all from the photos.

On the floppy drive, since you had the boards out, did you verify that the ribbon was pushed all the way down again? All it takes is a slight lift to one side. Or it may look like it's pushed down, and may actually be floating about an 8th inch up.

If you have a cleaning disk, put some fluid on it and stick it in a few times, let it eject, shove it back in.

Barring that, the next step involves taking it out.

But before all that, do you have more than one working disk, and none work or only one?

Are they double density? Not HD formatted as DD?

 

[HunterCupp]

Unless you have a cat, you don't need to have the back on the computer when your not using it, or can just slide it in.

I feel really good about claiming that you can't possibly break it trying to slide it off and on. They are -tight- to put on all the way. To get them off I usually do a slap and lift where it's face down on a sofa like surface, and in a motion like clapping symbols, my hands come together in a swooshing motion with an upward moving lift just as I'm making contact with the sides.

I do that a couple times, then put palms on the sides with thumbs over the mouse and serial port areas and squeeze palms while applying pressure to the exposed connectors to make the case rear slide up. Most of the time that opens it, if not I similar movement while pressing on the power switch or battery.

If that plastic case is really that brittle that it's cracking, you'd be seeing pieces falling off when you tried to open it. They really are quite sturdy, unless that one was sitting in a rotten hot, unbearable for a human, environment for years on end. It just does not look like that at all from the photos.

On the floppy drive, since you had the boards out, did you verify that the ribbon was pushed all the way down again? All it takes is a slight lift to one side. Or it may look like it's pushed down, and may actually be floating about an 8th inch up.

If you have a cleaning disk, put some fluid on it and stick it in a few times, let it eject, shove it back in.

Barring that, the next step involves taking it out.

But before all that, do you have more than one working disk, and none work or only one?

Are they double density? Not HD formatted as DD?

tdiaz

I have two cats and a dog, so I'll most likely put the case back on immediately after taking it off and doing what I need to do. As for the ribbon cable you speak of, I have no idea. I didn't think to check it at the time. I only have one floppy disk as of this very moment, it was a little hard to find a tested System 7.1 floppy, but I probably didn't search that well either. I have no idea if it is "double density" or "Not HD formatted as DD?". From what I can tell, it is one sided, and holds 800k.

-Hunter

 

[HunterCupp]

MacTech68 and tdiaz

I have come across another Macintosh Plus, this time, over eBay. I was able to get it for $20 with $10 in shipping. It is in pretty good condition from what I can tell, but the floppy drive doesn't work, and there are some cracks in the front casing and what looks like CRT burning in the display. The display is normal, so I figured that would mean that the analog board is in good, functioning, normal, condition, yes? I had the idea of carefully removing the analog board, no wires, from the new, more beaten up Macintosh, and switching it out with the other one. This would in ways fix the CRT I originally had a problem with, if this works out in real life how it does in my mind. As for the other Macintosh, I may keep it as a paperweight, resell it on eBay, or even mod it into an iPad dock or a Mac Mini of sorts? I would like all of your input on these ideas, as I do not even know if switching the analog boards would fix the problem. In theory, it should.

Thanks in advance.

-Hunter

EDIT: I found this interesting, the power switch on the back of my "new" Macintosh Plus is different from the power switch on my problematic Macintosh Plus, they're both the 1Mb version. Could the parts have bee swapped out of one of them at one point in time? The Macintosh Plus that has had the CRT problem has a smooth power switch, whilst the other has bumps/symbols.

 

[tdiaz]

You can slide the case most of the way on, to where it makes contact and leave it at that, and use a power strip for the power switch, until you're done working with it.

The power switch differences would be platinum vs. beige in color. Later on, it would not be uncommon to see the other color as in the case of third party repairs, you used what you had on hand. Boards were usually sent in for swapping, and you got back the next one they had, if they didn't have the same color switch you sent.

If you used a high density disk, it's possible that the disk has given up.

The ribbon cable is visible between the letters C and E. Push those connectors in. They should be flat with relation to what they are plugged in, and mostly disappear into the connector they're inserted.

 

[HunterCupp]

You can slide the case most of the way on, to where it makes contact and leave it at that, and use a power strip for the power switch, until you're done working with it.

The power switch differences would be platinum vs. beige in color. Later on, it would not be uncommon to see the other color as in the case of third party repairs, you used what you had on hand. Boards were usually sent in for swapping, and you got back the next one they had, if they didn't have the same color switch you sent.

Image

If you used a high density disk, it's possible that the disk has given up.

Image

The ribbon cable is visible between the letters C and E. Push those connectors in. They should be flat with relation to what they are plugged in, and mostly disappear into the connector they're inserted.

tdiaz

The floppy disk seems not to be a high density disk. From what I can also see about the floppy drive, everything seems to be in proper order. I'll attach pics of everything.

-Hunter

 

[MacTech68]

I have come across another Macintosh Plus....The display is normal, so I figured that would mean that the analog board is in good, functioning, normal, condition, yes? I had the idea of carefully removing the analog board, no wires, from the new, more beaten up Macintosh, and switching it out with the other one. This would in ways fix the CRT I originally had a problem with, if this works out in real life how it does in my mind.
EDIT: I found this interesting, the power switch on the back of my "new" Macintosh Plus is different from the power switch on my problematic Macintosh Plus, they're both the 1Mb version. Could the parts have bee swapped out of one of them at one point in time? The Macintosh Plus that has had the CRT problem has a smooth power switch, whilst the other has bumps/symbols.

...The power switch differences would be platinum vs. beige in color. Later on, it would not be uncommon to see the other color as in the case of third party repairs, you used what you had on hand. Boards were usually sent in for swapping, and you got back the next one they had, if they didn't have the same color switch you sent.

Yup, this is very true - repairs via an Apple dealer meant swapping the whole analog board - your failed board went to a level 2 repair depot and was then repaired and sent back into parts stock for the next person requiring an analog board swap. As improvements were made for reliability, these would be applied as the failed boards were sent to level 2 repair depots.

I've also got an analog board with a red colored battery holder. I'd love to know if there is any knowledge on that one.

Regarding swapping the analog boards, this is certainly do-able, but requires certain adjustments be performed after the swap. You would need a multimeter, and a plastic hexagonal alignment tool and a method/tool for discharging the CRT.

The only other issue is how many revisions each analog board is. I'd hate to replace a late revision (albeit partially faulty) with a significantly earlier revision, but that's just me.

 

[HunterCupp]

Yup, this is very true - repairs via an Apple dealer meant swapping the whole analog board - your failed board went to a level 2 repair depot and was then repaired and sent back into parts stock for the next person requiring an analog board swap. As improvements were made for reliability, these would be applied as the failed boards were sent to level 2 repair depots.

I've also got an analog board with a red colored battery holder. I'd love to know if there is any knowledge on that one.

Regarding swapping the analog boards, this is certainly do-able, but requires certain adjustments be performed after the swap. You would need a multimeter, and a plastic hexagonal alignment tool and a method/tool for discharging the CRT.

The only other issue is how many revisions each analog board is. I'd hate to replace a late revision (albeit partially faulty) with a significantly earlier revision, but that's just me.

MacTech68

I will open the other Macintosh in the morning and take a few pictures of everything there including the analog board. Fingers crossed it's in the same revision stage. Also, I will have no problem opening and closing my Macintosh Plus anymore, I have found what I believe to have been the problem that caused one of the corners to be stuck and very difficult to close. There is a metal clamp of sorts above the audio port in the back of the logic board which is used to house the guide for a screw, it was bent at an odd angle, out of socket, making it scrape and wedge every time I attempted to close it. I was able to fix it by using a small wrench style clamp of mine and bend it back to shape. I will attach pictures of before and after I fixed it, and the other clamp to show what it is supposed to look like.

-Hunter

EDIT: As for the Floppy Drive, if the cleaning doesn't work and I am to suspect the worse, a failure or something of the sort. Couldn't I technically just buy an external Apple Floppy Drive? That's just if the worst case scenario happens, anyway.

 

[tdiaz]

Disk Drives.. easy peasy.

I usually do them a lot faster than in this video..

http://www.kansasfest.org/2012/08/2010-diaz-maintenance/