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monoxrom
July 5th, 2011, 11:10 PM
Hello!
I have a problem
One day my Macintsoh Classic II can't starting. I have some strange rectangle on screen and disturbing sounds from speaker

This is video:
http://www.youtube.com/watch?v=Rud-_FVFJoQ

What is with mac? :(

DOS lives on!!
July 6th, 2011, 04:58 AM
That does look scary!!! I don't have a Mac Classic, but I think it's a hardware problem. At least it was working enough to make the sad mac sound.

Roman78
July 6th, 2011, 05:14 AM
Looks like the high voltage of your screen alignment is faulty. The boot sound is normal.

You could open it and try to adjust your screen. There should be some potentiometers to do this..

DOS lives on!!
July 6th, 2011, 05:26 AM
That boot sound isn't normal, that's the sad mac sound indicating a software issue. The square in the screen is most likely a hardware problem.

RetroHacker_
July 6th, 2011, 06:03 AM
Definitely something wrong with the video. It's folding over at the top, could be a lot of things wrong. Try disconnecting the logic board and crank up the screen control and see if you can get a fully scanned raster out of the monitor. If not, then you need to troubleshoot that first before you work on the computer section. The foldover could be anything from cold solder joints on the vertical transistors to failing electrolytic caps.

A common failure in these machines is the surface mount electrolytics on the logic board. But, usually that produces a checkerboard pattern on the screen. The "Dead Mac Chimes" can be caused by several things - bad RAM, bad contact with the RAM, failing logic board, etc. You should get a happy "Ding!". Even with no hard disk, you should get a "Ding!" and a flashing question mark diskette icon on the screen.

But, first things first. Check the power supply voltages.

-Ian

twolazy
July 6th, 2011, 09:20 AM
I agree with Retro here, most likely caps or the flyback transformer. I'd check the caps first. Also while open, remove the pram battery and check for corrosion. The caps are surface mount, tiny and silver. Check for any goo around them. Any that have a film under them, replace. I just got done replacing all the caps in my Classic. Its a pretty easy job provided you have the tool to open the case.

You will need a really long T-15 torx screwdriver. What I ended up doing was took a cheap $1 t-15 from ace, and broke the handle off with a hammer. I then welded a small 1/4" 5.5mm socket, just big enough to fit around the screwdrivers shaft onto the end. Now it reaches! Improvisation may be required for this tool... If you get stuck not being able to get one made/purchased, contact me and I can make you one for cost + shipping.

RetroHacker_
July 6th, 2011, 10:53 AM
I agree with Retro here, most likely caps or the flyback transformer.

It's most definitely not the flyback. If the flyback was bad, you would have no high voltage and thus no picture.



You will need a really long T-15 torx screwdriver. What I ended up doing was took a cheap $1 t-15 from ace, and broke the handle off with a hammer. I then welded a small 1/4" 5.5mm socket, just big enough to fit around the screwdrivers shaft onto the end. Now it reaches! Improvisation may be required for this tool... If you get stuck not being able to get one made/purchased, contact me and I can make you one for cost + shipping.

You can make a much simpler one... Take a BIC ballpoint pen apart - the kind with the soft white plastic barrel. Remove the ink cartridge and the end stop and throw them away. Then jam a standard T15 driver bit into one end - it'll wedge nicely into the soft plastic. Into the other end of the pen, jam a pencil - the normal yellow hexagonal kind. It will also jam nicely into the plastic. The combined tool is the right length (and sturdy enough) to remove the two recessed Torx screws inside the handle.

-Ian

twolazy
July 6th, 2011, 01:01 PM
I've seen weird focus distortions similar to his situation occur with bad flyback transformers , not with macs persay but with vga monitors. If it was indeed bad you would notice a faint buzzing sound at the rear of the unit. Good idea bout the tool btw, not sure if a pencil hold up for the long term though. Guess as long as it gets the job done who cares... :thumbsup:

Now that i think of it guess u could file down the end of the screwdriver shaft to fit a socket too, i just welded it, it was far easier ... took a whole 2 mins tops :)

monoxrom
July 7th, 2011, 04:07 AM
Thank you all for answers.
I must say, from the beginning of the story was something wrong. Screen on "mac" was another first (not good). I was access to inside computer and replace some capacitors in place where power connector go to CPU motherboard because voltage +12 and +5 was not good. Original capacitors were wet on bottom. And i was replace this all to another, but another was not new.. something of them have around 20 years like "mac" ((( But they looks good.. When i replace capacitors im have that screen, as video on firs post... Maybe i need to use all new capacitors? And need to replace all electrolytic capacitors?

monoxrom
July 18th, 2011, 10:46 PM
Hm.. i was replace all electrolytic capacitors but problem persists
And yesterday i was get motherboard from macintosh classic (first mac) and this board was starting good!

Maybe in my motherboard some rom chip failed :(