The classic starts up on my original (Apple) Mac Os 7.6 Disk Tools 1 floppy. I also have Disk Tools 2 floppy.
System is 7.0.1 now.
Before I try to install can you remind me of the correct installation sequence with Apple HD SC Setup?
Thank you for your input.
Classic II-OTHER, Mac OS 8.6 or Earlier
>Do you know about the use, function of the Reset and Debug- switches?
The reset switch can be used to restart a Macintosh computer in case of a system crash or a similar problem. The debug/interrupt/programmer's switch is intended for special tasks (the article https://developer.apple.com/library/archive/technotes/tn/tn1136.html#//apple_ref /doc/uid/DTS10002975 could perhaps also be of interest in this context).
>From the El. caps I can see I see no bulging, discolorations.
Unfortunately, capacitors may be bad without visible signs of failure. If a Macintosh Classic II computer has worked OK earlier and then develops a sound problem, one of the things to investigate/suspect would be bad capacitors. Just as an example, the web page https://wiki.68kmla.org/Capacitor_Replacement has more information.
>Do you know about the use, function of the Reset and Debug- switches?
The reset switch can be used to restart a Macintosh computer in case of a system crash or a similar problem. The debug/interrupt/programmer's switch is intended for special tasks (the article https://developer.apple.com/library/archive/technotes/tn/tn1136.html#//apple_ref /doc/uid/DTS10002975 could perhaps also be of interest in this context).
>From the El. caps I can see I see no bulging, discolorations.
Unfortunately, capacitors may be bad without visible signs of failure. If a Macintosh Classic II computer has worked OK earlier and then develops a sound problem, one of the things to investigate/suspect would be bad capacitors. Just as an example, the web page https://wiki.68kmla.org/Capacitor_Replacement has more information.
Thank you so much for all your very helpful information!
Now that I have a Classic II that starts up I really want to get sounds working.
Yes there is no start-up sound or any other which I had when I first got it..
Before I work on the unit I discharge the high voltage with a screw driver and wire connected to the chassis by the AC jack, touching the high voltage connector going into the tube. I also wear high voltage rubber gloves I bought years back.
I could not locate a schematic, parts diagram on the net.
It looks like there are 2 circuit boards in this machine.
1. The mother board (with the 2 RAM chips) which I took out after disconnecting the 3 connectors.
All looks clean, no discoloration.
2. The large power supply board which is covered underneath with Apples white paper warning of high voltage.
It has all caps transformers a.s.o.
From the El. caps I can see I see no bulging, discolorations. Since all of the bottom is covered with the white warning paper I am not able to see the bottom of the board. (I might remove that covering)
There is no sound out of the mono sound-out jack.
I will try and find the speaker and repost.
Do you know about the use, function of the Reset and Debug- switches?
Thank you so much for your continuing help.
I did find this block diagram:
Macintosh Classic II: Technical Specifications
Yes, it is possible to install System 7.6 onto a Macintosh Classic II. However, it may or may not be the best operating system for this model. You will probably notice that System 7.0.1 is faster (the same would be true for System 7.1), and it occupies less space on the hard disk. A full set of floppies is required for the installation (can be made from images on the System 7.6 CD), not only a Disk Tools disk. For better results, make sure that the Classic II has the maximum amount of RAM (10 MB total).
Apple HD SC Setup is used to reformat/initialise the hard disk. This will erase everything on the hard disk, so make sure that you have backup copies of important files before you try it. It is not absolutely necessary to reformat a properly working hard disk just for the purpose of upgrading the system, though.
If you need more details, please post back and mention whether you have a full set of System 7.6 floppies, or whether you intend to use an external SCSI CD-ROM drive for an installation from a System 7.6 CD (special techniques required).
Thank you so much for your very helpful info! If you please, I need further after I replace the 6.3 volt Pram battery that just gave up on me. I ordered from the net a. will repost when I am up and running again. Thanks again for your time a. patience.
OK I am backup a. running with a new battery.
The reason I wanted to install 7.6 on my Classic II is because It has no sounds and I thought that might bring back the sound I had when I first got it.
Also Disk Tools 1 a. 2 by Apple is the only install floppies I have. Now that you said 7.6 might slow down the Classic II? It runs well on 7.0.1.
I do not have internal, external floppy drives for my Macbook 7,1 or MacPro 4,1 to make 7.0.1 Install-floppies to re-install.
I ran Disc Utility, Silver Lining, Techtool. All No Problems found. I tested the memory, reset the PRAM a. rebuild the Desktop, still no sound!
I took out the mother board: All looks normal. I can’t find the speaker, may be its on the power-board?
Techtool says Logical RAM Size is 8,388,608 Virtual Memory Present.
I have no clue where to go from here to get the sound working. Plugging in headphones no sounds as well.
Hi,
Any system sounds inside the System suitcase?
I do not have access to my System 7.6 CD right now, but if I remember correctly there were several disk images on that disc intended for the creation of a set of system floppies. A Disk Tools floppy (two 7.6 types, depending on computer and hard drive) is normally used to verify/repair/reformat a disk only. Sometimes, one could also drag-copy a system folder from an appropriate tools floppy onto an empty hard disk in order to obtain a minimal temporary system on the latter (this would then free the floppy drive for subsequent file transfers).
Re-installing System 7.0.1 would probably be good first step.
The Classic II could per se be used to create floppies from disk images, providing that you have och can get the necessary utilities.
Do you have access to an (older) Windows PC with a floppy drive? Alternatively, a friend with a floppy-equipped (pre-1998) Macintosh computer with a CD-ROM drive and Ethernet?
Do you have a serial modem for the Classic II? Do you have any kind of communications software (could, for example, be a dedicated terminal emulator with file transfer capabilities or the communications section of ClarisWorks)?
There should be a speaker in the lower left front section of the computer.
A word of warning: As you probably already know, all work inside a compact Mac like the Classic II is dangerous because of the high voltages involved, and must be performed by someone with the necessary expertise only. Dangerous charges can remain in various areas/components even when the computer has been switched off and disconnected from the mains.
Addendum
When you say that the Classic II has no sounds, would it be correct to assume that this includes the startup sound?
A system software re-installation may not help at all. One should also check for a possible fault in the sound circuits (headphone jack, wiring, etc), or another hardware problem. Any signs of bad/leaking/discoloured electrolytic capacitors?
Can I install system 7.6 software into a model 4150 Macintosh Classic II?
