My trusty Mac LC no longer boots from the HD

Hi Len,

Do you still have the external SCSI enclosure (with its own power supply)? Has the remaining hard drive been tested again, both installed internally and in the external box? No sound of a spinning disk?

It is strange. I guess that you have double-checked all cables etc. Yes, it may become necessary to test yet another hard drive, but before doing so you should really have a set of disk tools floppies with various utilities (such as Apple HD SC Setup 7.3.5, Lido 7.5.6 and Mt. Everything). It is not too difficult to adapt Network Access disks to hold the utilities in question, but you would need a working older Mac with a hard drive to do so. Perhaps it is time to look for something like a PowerBook 520/520c/540/540c (which has built-in Ethernet) to be used for floppy modifications and as an intermediary.

Jan

Addendum

If you can find someone with a suitable older (approx. 1991 to 1997) Macintosh computer, here is a list of older Apple software:

http://www.info.apple.com/support/oldersoftwarelist.html

A plain Network Access Disk 7.5 can be used as a general startup disk (and, as mentioned earlier, it can be the base for utility disk modifications). It can also be used to access files on another Mac via a simple LocalTalk network (a normal MiniDIN-8M to MiniDIN-8M printer cable between the serial printer ports):

http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/Utilities/Network_Access_Disk_7.5.sea.bin

Disk Copy 4.2 (the Make A Copy button) can be used to create a properly sector-copied floppy from a downloaded NAD 7.5 disk image:

http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/Utilities/Disk_Copy/Disk_Copy_4.2.sea.bin

Apple HD SC Setup 7.3.5 can be found here:

http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/Utilities/Apple_HD_SC_Setup_7.3.5.sea.bin

For information about other programs, you may want to try an Internet search for something like 'format SCSI Mac'.

Please note the volume size limits:

http://support.apple.com/kb/TA2711

Mt. Everything can be used to detect a drive on the SCSI bus:

http://www.overnet.de/hhp/mte/

SCSI Probe was a similar utility:

http://support.apple.com/kb/TA48033

BTW, with an appropriate cable/adapter, many PowerBook computers can act as an external hard drive in SCSI disk mode (see, for example, page 31 in the PB 500 series manual below).

http://manuals.info.apple.com/MANUALS/0/MA640/en_US/PowerBook_500series_UserGuid e.pdf

Jan

Hi Len,

>but the 'new' logic board couldn't find either of them.

The first requirement for a hard disk to become visible on the Desktop is of course that it has been properly formatted/initialised (with an appropriate driver installed). The second would be that the SCSI bus/chain is OK. Otherwise, the hard disk will not mount.

When you say that no SCSI drive could be found, was that a result of a drive search in an old HD SC Setup program on a Disk Tools floppy? HD SC Setup may have difficulties detecting drives; third-party drives (or Apple drives with an altered formatting) cannot be expected to appear at all. It is really essential to have access to alternative tools.

Is there an Apple User Group in your area? If so, someone there could perhaps help you locate a suitable older Macintosh computer.

http://www.apple.com/usergroups/

A problem with the power supply under specific load conditions cannot be ruled out, but it all seems to work well with the floppy drive.

If necessary, do not hesitate to post back later with questions about floppy modifications etc.

I wish you a Merry Christmas!

Jan

Hi Len,

>When power is first applied to the computer at start up, should the internal HD begin to spin even before the boot sequence has gotten very far?

I tested this with my LC III (which has a Conner 30080E hard drive). Nothing was connected to the (external) SCSI port. To be able to hear the hard drive better, the fan was temporarily disconnected. Immediately after the computer was turned on, the hard drive started spinning. Shortly thereafter, the startup sound could be heard. Then the arrow appeared. After that a Happy Mac followed by the Welcome to Macintosh message, and the normal Desktop.

Another test with the SCSI (hard drive) cable disconnected at the board had the same result (the hard drive spinning up and then the startup sound). Then the arrow. Finally, a floppy icon with a flashing question-mark was shown on the screen. No Happy Mac etc. Upon insertion of a Network Access floppy, the Happy Mac appeared, followed by Welcome to Macintosh, and eventually the normal Desktop.

Jan

Hi Len,

Thank you. I wish you a Happy New Year, too!

As far as I know, Apple never published schematic diagrams for any product. However, they did publish block diagrams for various computer models in their Developer Note series. Earlier, you could download these hardware documents from Apple's developer site, but this does not appear to be true any more (a web search could possibly provide some results, though).

As far as the sound is concerned, did you check whether a switch in the speaker/headphone jack properly closes the circuit to the internal speaker when nothing is connected externally? If necessary, a small amount of a good contact cleaner may help.

Glad to hear that you solved all the other problems.

Kind regards,

Jan

Not sure if this is directly related - but the Inside Macintosh had some very techical details to the hardware and software. There was some basic schematics when I read through them. The books were sold to developers back in the day, and you can get them at a yard sale price on Amazon (which I got the first 4 volumes in the last year or so.)

Hi stevena1,

>Apple never published schematic diagrams for any product.

Just to clarify, I was referring to 'component level circuit diagrams' in this very case.

Earlier, developer notes (which often contained block diagrams) for old hardware products could be found here:

http://developer.apple.com/documentation/Hardware/Hardware2.html

Unfortunately, that address now returns an error message. However, one should perhaps not rule out that the page exists in an Internet archive somewhere. Generally speaking, it has become increasingly difficult to locate older Knowledge Base articles, etc. Sometimes the material is still available at an Apple web site, but you may have to use Google to find it.

Jan

Hi Jen,

I'm also experiencing the same issue as Ien-35: Internal HD not detected to boot. And Utilities 2 floppy says cannot detect an SCSI connected disc. Booting from the floppy is ok. Also the external HD is working but my applications (now they say "apps" ;-) are on the internal HD so cannot even read simple docs.

In this case I'm "keeping" my "old tek" museum alive and one of the oldies is this LCIII with an 80MB HD, 20MB RAM and external SCSI (not sure if it was 1GB or less)

I read your thread and my symptons are similar: the HD spins a bit when power on then system thinks a bit, spin again (more or less at the same time the fan does) and stops and the requuest for the floppy with the question mark appear on display.

I will revise the caps as Ien-35 did but what do you think if I replace the external hd with my internal HD, I mean a physical change: will the system try to boot from the external scsi if they ffind a bootable disk there? ... Probably I will try this anyway but would like your opinion.

tks!

Hello Oldmac25,

>if I replace the external hd with my internal HD, I mean a physical change: will the system try to boot from the external scsi if they ffind a bootable disk there?

If an external enclosure contains a working hard disk drive with a valid system folder, the computer will (normally) be able to boot from there (providing, of course, that one connects devices according to the general rules for SCSI). If necessary, one can bypass an internal hard drive by holding down the four keys Command(Apple) + Option(Alt) + Shift + Delete(Backspace) during startup. A SCSI utility such as Mt. Everything (see above) could perhaps be useful, too.

BTW, does the existing external hard drive have an operating system, or is the disk merely used to hold documents?

Jan

Thanks Jan, too fast answer for this slow speed Macs blog ;-)

As my external scsi runs well when booting from floppy I will make the change just to see if the internal hd is still ok. If it is ok then the problem may be related with the board or power as you advised to Ien and will work there. I'll tell you know what I learn.

The actual external does not contain a system, just docs. So I will physically replace the HD of the external enclosure with my internal HD just to check if the internal HD is working since it is not detected at startup.