Cross Compatible CRT?

[iMac600]

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.

 

[The Macster]

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

 

[iMac600]

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.

 

[Patrickool93]

What is the manufacture date or serial number?

 

[iMac600]

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.

 

[tomlee59]

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.

 

[iMac600]

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.

 

[tomlee59]

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 Since sadly Gamba is no longer among the living, I can't replace the out-of-date one that's posted on his site.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)?

 

[equill]

... 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

 

[tomlee59]

Thanks for the encouragement, equill -- I do appreciate it greatly.

Now for a really dumb question: Where/how do I upload this doc?

 

[equill]

... 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

 

[~tl]

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.

 

[Kallikak]

Except a thread won't include pictures...

 

[MacJunky]

upload to imageshack and post thumbnails?

 

[tomlee59]

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).

 

[The Macster]

You could always just put it on one of the free file-hosting websites.

 

[coius]

I would be willing to host it on my site. Let me know, give me a PM.

 

[~tl]

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...

 

[Kallikak]

Hosting it here is far and away the best option.