Thread
Cross Compatible CRT?
I still have the CRT, Analog and Power Supply assembly from my Macintosh Classic. It still works and all, so I can put it to use in something else.
There's a Macintosh 512k on eBay at the moment which claims to have a "Dead Display". I'm assuming the CRT.
Probably not, but asking doesn't hurt... is there some chance that i'll be able to connect in my old Classic CRT in to the Mac 512k? If not, is it still worth getting this old Mac despite it being "CRT Challenged"?
I'd rather not post the link at risk of being outbid by someone local (it happens!), but I will if absolutely necessary.
There's a Macintosh 512k on eBay at the moment which claims to have a "Dead Display". I'm assuming the CRT.
Probably not, but asking doesn't hurt... is there some chance that i'll be able to connect in my old Classic CRT in to the Mac 512k? If not, is it still worth getting this old Mac despite it being "CRT Challenged"?
I'd rather not post the link at risk of being outbid by someone local (it happens!), but I will if absolutely necessary.
Only if your Classic was a Rev. A, as under discussion in this topic. PS it's not difficult to find the listing even with no link 
It's probably only worth getting if it's local as postage on something heavy like that is going to kill you, especially given that it's dead and you can't be sure whether it's even fixable until you get it
It's probably only worth getting if it's local as postage on something heavy like that is going to kill you, especially given that it's dead and you can't be sure whether it's even fixable until you get it
I'm thinking it is a Rev. A as it is capable of booting from ROM, something that was removed in later Classics if I recall correctly.
What is the manufacture date or serial number?
August 1991 afaik. I can't check for certain as the Classic itself was thrown away long ago, and only the CRT assembly remains.
EDIT: Actually I still have the case, but it's in the shed which is now locked up for the night.
EDIT: Actually I still have the case, but it's in the shed which is now locked up for the night.
The "dead display" problem is very common. Although it can be caused by a bad crt (from shipping damage, say, or a repair job gone wrong), more often it's a fault on the analog board. Bad solder joints on the yoke connector (J1), bad capacitor C1, and a dead flyback are the three most common causes of a dead display.
If it is a dead crt, then you can certainly transplant the crt from your Classic into it. The yoke may not be suitable, but the crt itself almost certainly is.
If it is a dead crt, then you can certainly transplant the crt from your Classic into it. The yoke may not be suitable, but the crt itself almost certainly is.
I forgot to mention that mine seems to be a less-common Samsung CRT assembly... but it should still work either way.
I'll be watching this 512k then.
I'll be watching this 512k then.
This recent thread on CRTs and dead compacts in general has gotten me off my brains long enough to do a small update of my compact-Mac repair notes. Mainly, I added some pics and rearranged the material to orient it more toward repair of common faults than documenting Mac engineering. Since sadly Gamba is no longer among the living, I can't replace the out-of-date one that's posted on his site. Any ideas (assuming that there's any interest)?
Most certainly. That, your schematics and the original analysis of AIO CRT capacitance could have pride of place in the much-canvassed but little-developed info. pages for this Army. Anything for which you retain publication rights would grace this Army's armory of information, and often serve as source material to reference from the also much talked-about FAQs that were being discussed before The Dive.
de
Thanks for the encouragement, equill -- I do appreciate it greatly.
Now for a really dumb question: Where/how do I upload this doc?
Now for a really dumb question: Where/how do I upload this doc?
Why not PM ~tl and ask him whether a sticky or stickies will do for starters, pending its or their later enshrinement in the presently vapourware FAQs? He has a decided interest in such things as the proprietor of the Forum, and will have a better idea than I do about the possibilities.
de
If you want to post it as a new thread, I'll make it a sticky topic. There have been talks about starting some sort of "information archive", but until that gets off the ground then a sticky is the best bet.
Except a thread won't include pictures...
upload to imageshack and post thumbnails?
Unfortunately, I'll have to wait. My doc is a pdf (started life as a Frame doc), and it doesn't sound like we're quite at the point of having a collection of files stored somewhere.
I could post it somewhere on my university's website, but they officially frown upon such things (although enforcement is very lax, typically).
I could post it somewhere on my university's website, but they officially frown upon such things (although enforcement is very lax, typically).
You could always just put it on one of the free file-hosting websites.
I would be willing to host it on my site. Let me know, give me a PM.
How big is it? I'm sure we could spare a bit of server space here at the MLA if you want to have it hosted here...
Hosting it here is far and away the best option.
Thanks for all the offers, guys. I appreciate it!
It's not a very big file -- it's mainly text, with a half dozen pics or so. I don't have it before me at the moment, but I doubt that it's bigger than a couple of megs. If hosting it here is possible, then that would be great. Tom -- let me know how to upload it, and I'll get this puppy out of here.
Thanks again!
It's not a very big file -- it's mainly text, with a half dozen pics or so. I don't have it before me at the moment, but I doubt that it's bigger than a couple of megs. If hosting it here is possible, then that would be great. Tom -- let me know how to upload it, and I'll get this puppy out of here.
Thanks again!
Yes. Please do. I just threatened some of the more timorous in the ranks with your charge computation and risk analysis for AIO Compact Macs. It will be good for them to read it for themselves.
de
de
I suppose I count as one of those then
Even though I know that you both know your stuff and are therefore likely to be right that a compact Mac won't kill you, I would still be too scared to see the insides of one - I don't know what it is, but these things just scare me somehow :I There'd be no point me opening one up anyway as I wouldn't be able to fix a dead one, nor do have any of the special tools required, so I don't suppose it'll be happening any time soon regardless!
Hi Macster,
It's all right to be a bit frightened -- it just means that you have good self-preservation instincts. But even if you don't think you could fix these things, I'm sure that you could. And an AIO compact is a great vehicle for learning how to troubleshoot and repair simple problems. You don't need any special or expensive tools in most cases -- aside from the longggg Torx driver needed to open them up. A cheapo soldering iron will go a long ways toward repairing the most commonly encountered problems.
Dan Knight at LEM was kind enough to reprint an updated version of an old applefritter article I wrote on the CRT discharge question. If you're interested, you can find it at http://lowendmac.com/tech/crt_danger.html. But the short version is:
1) A zap from an AIO won't kill you, but it can hurt, just as any other static zap on a dry day.
2) It's easy to avoid even that unpleasant zap.
3) Most repairs don't require touching the HV bits, so don't touch them, and you can sidestep the whole zappage issue.
The AIOs are really as harmless as they are cute. Just let them sit unpowered for a day or two, and the biggest danger they'll present is allergic reactions from the dust that's inside.
It's all right to be a bit frightened -- it just means that you have good self-preservation instincts. But even if you don't think you could fix these things, I'm sure that you could. And an AIO compact is a great vehicle for learning how to troubleshoot and repair simple problems. You don't need any special or expensive tools in most cases -- aside from the longggg Torx driver needed to open them up. A cheapo soldering iron will go a long ways toward repairing the most commonly encountered problems.
Dan Knight at LEM was kind enough to reprint an updated version of an old applefritter article I wrote on the CRT discharge question. If you're interested, you can find it at http://lowendmac.com/tech/crt_danger.html. But the short version is:
1) A zap from an AIO won't kill you, but it can hurt, just as any other static zap on a dry day.
2) It's easy to avoid even that unpleasant zap.
3) Most repairs don't require touching the HV bits, so don't touch them, and you can sidestep the whole zappage issue.
The AIOs are really as harmless as they are cute. Just let them sit unpowered for a day or two, and the biggest danger they'll present is allergic reactions from the dust that's inside.
I don't know, I'm just not an open-it-up kind of person when it comes to Macs and the like - I would only open something up if there was a good chance that I could fix it and no chance of making it worse by opening it. Neither of those are true, given that I'm not a hardware guy! Usually you would need a replacement part that I wouldn't have lying around anyway, as well as knowledge of soldering etc to fit it, which I could never do. Like with the Duo 230, I would only make it worse by opening it up and probably couldn't even get it to go back together (and don't have these weird "Torx" screwdrivers that you seem to need for the screws on these things anyway), and don't have any parts for them, so I will probably just leave it languishing in a drawer somewhere, dead
I'll leave the hardcore Mac-opening that I'm always hearing tales of to you guys!
Tom Lee is right...a lot of people are a lot more scared of the innards of comapct Macs than they should be....you really don't have to be scared. But then again, my basic rule regarding these sorts of things is, "The thing is broken, so why not OPEN it? Grab a screwdriver, you've got nothing to lose". [}] ]'>
] ]'>Except that you do have a lot to lose and not a lot to gain, at least if you're like me ie not a hardware wizard - if I opened my Duo 230 I would just make things worse by breaking more of it, not being able to get it back together etc!"The thing is broken, so why not OPEN it? Grab a screwdriver, you've got nothing to lose". [}
LCguy is right -- if it's already broken, then it's hard to make things that much worse.
And that's what you need for your first repair experience -- a junker already destined for the scrap heap. I'm willing to bet that the satisfaction you'll feel from bringing the dead back to life will encourage you to do more. Then you'll eventually get to the point where you'll feel confident about opening up a still-working machine to do upgrades and light maintenance. But first things first: Find a DOA Mac (there are so many!), and revive it.
And that's what you need for your first repair experience -- a junker already destined for the scrap heap. I'm willing to bet that the satisfaction you'll feel from bringing the dead back to life will encourage you to do more. Then you'll eventually get to the point where you'll feel confident about opening up a still-working machine to do upgrades and light maintenance. But first things first: Find a DOA Mac (there are so many!), and revive it.
Tom Lee is right....the best way to get good and improve your confidence with hardware repair is to repair a broken one. A lot of the best computer techs got their start with old broken/dying equipment and then moved onto better stuff once they felt they were up to it.
Well the Duo 230 is in very good condition cosmetically so it's too good to be classified as a junk machine for ripping in to, I would feel bad about completely breaking it. And seeing as we think it has no hard drive, there's no way I could get it working anyway (and the fact that the screen is probably dead or it needs a new capacitor or something like that, neither of which I could possibly deal with either). The only machine I would be happy to rip into as a training machine would be something that really was scrap, like a 286 laptop with a caved-in screen or something like that which (1) has any chance whatsoever of working again, (2) is not a machine that you feel has some sort of "character" (like the Macs always seem to) and (3) is not something that has any value that you could realise by selling it as a parts/repair machine.
I'll test the Zip drive when I have the chance, to see if that has come back from the land of the dead or not. Best to start small eh? (of course that fulfilled the 3 criteria above, so I didn't feel bad about opening it up as I was only going to throw it away anyway)
I am now just about confident enough to do light upgrading of a working desktop Mac (I did some stuff in the G3 for instance), but never a laptop.
(and the fact that the screen is probably dead or it needs a new capacitor or something like that, neither of which I could possibly deal with either). The only machine I would be happy to rip into as a training machine would be something that really was scrap, like a 286 laptop with a caved-in screen or something like that which (1) has any chance whatsoever of working again, (2) is not a machine that you feel has some sort of "character" (like the Macs always seem to) and (3) is not something that has any value that you could realise by selling it as a parts/repair machine.I'll test the Zip drive when I have the chance, to see if that has come back from the land of the dead or not. Best to start small eh?
(of course that fulfilled the 3 criteria above, so I didn't feel bad about opening it up as I was only going to throw it away anyway)I am now just about confident enough to do light upgrading of a working desktop Mac (I did some stuff in the G3 for instance), but never a laptop.
It may be in good condition cosmetically, but even so, if it doesn't work, what value does it have to you? All it does is take up space...so really, you may as well have a look at getting it to go...otherwise its just a paperweight.