Member Avatar for mrfixit

Need your help please i have a 97 apple power mac G3 model m4405 with floppy drive ,cd drive and single hard drive the problem started sunday i went out with a few friends to a club to watch the superbowl game and my son thought he would help his dad fix the computer. He pulled all the ribbon cables and power cables off the motherboard so he could clean the machine better for his dad. Thank god it wasnt plugged in! The problem now is i dont have the first clue how the cables went? The power cables i figured out but the ribbon cables have me stumped?? its an ide system but the motherboard has three connecters one 50 pin and two 40 pins none are labled on the board so i dont know what goes where??? The computer is all factory with no modification at all. I figured out the floppy drive that one was eazy,but dont know how to hook up the rest?? Five year olds can do damage!!!! Brought it over to local pc repair store and the apple repair man said unit was to old for him to fix??? Unit worked great before this mishap. any help you can give me will be greatly appreciated. sincerely mr fixit :sad: p.s. can be contacted by e-mail at using wifes computer thanks

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Short, practical recovery plan that picks up where left off and builds on the pointers from , , and . The goal is to recover the machine without guessing which cable goes where and to protect the hard drive contents first.

  1. Photograph and label first. Take clear pictures of the whole interior, a close-up of the motherboard area with the loose ribbons, and one of the drive bay showing jumpers and connectors. Put a small piece of masking tape and a number on each detached cable so you can keep track.

  2. Isolate the boot drive and test it externally. Remove every removable device except the single hard disk that used to boot the Mac. Before fiddling with on-board connectors, remove that drive and test it in a known-good machine or in a USB-to-IDE enclosure. If the drive is readable there, image or copy the data immediately — imaging first preserves the data if later steps fail.

  3. Reconnect only one drive for initial power-on. Reinstall the tested drive and connect a single ribbon and power lead (no CD or extras). Make sure the ribbon seats squarely; do not force it. Power up and observe activity (spin, chirp, chime). If it still will not show up externally but works in the tester, the issue is likely which header was used, a damaged cable, or a board fault.

  4. Hardware checks before more swaps. Inspect for bent pins, cracked plastic posts, or scorched traces near the connectors. Old ribbon/Molex cables get brittle — try a replacement cable before extensive troubleshooting. A multimeter can confirm the drive is getting the expected voltages at the Molex power connector.

  5. Service documentation and last-resort steps. If identification of the correct header is still unclear, consult the Power Mac G3 service manual (service diagram shows board silk-screen labels and connector pinouts) and, if data is critical, image the drive first and then seek a retro-Mac specialist rather than repeated random swaps.

This sequence protects data, minimizes trial-and-error on the motherboard, and gives the clearest information to volunteers or a repair shop when photos and a drive image are available.

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Member Avatar for DMR

The 50-pin connector is the internal SCSI connector; if your system is stock, this won't have anything connected to it.

The two 40-pin connectors are the Primary and Secondary IDE channels; your hard drive should be plugged into the Primary channel's connector. I haven't worked on Macs in a few years and don't remember which connector is which on that particular model. Is it a desktop or tower?

Member Avatar for Thong_Ispector

Question 1...
Do you have two 40 pin cables left over or one...

The cables are keyed... Red Marker goes to pin 1

You have primary and secondary IDE connections to the motherboard.

If you accidentally connect you hard drive to the wrong one it simply will not boot, but it will not do any damage. (Just have polarity correct)

Look for a mark on the motherboard like IDE-0 that will be your primary

If you have IDE-1 and IDE-2 then IDE-1 is your primary or hard drive

If you only have one cable and it goes to both the hard drive and the CD-Rom or DVD it still goes to the primary IDE

If both your hard drive and CD are on the same cable it (seldom) matters which is connected to which. Some cables are CS or cable select. If you look at your drive (either one) and it is jumpered as primary / master or slave then it is not a CS cable and can be connected either way.

Try one bus and if it dosent boot then switch to the other bus...

The only dangerous thing you can get wrong is the polarity of the cable and 99% of those are keyed and only connect one way...

The other is trial and error... it works or it dont and you switch them...

Member Avatar for kc0arf

Hello,

This wasn't in the Apple Hardware forum, so took me a while to find it. The situation is not as dire as you think, and that Apple fella you talk to at the store should be shot for sending you away like that. I could see if you wanted him to add memory to a Mac Plus or something, but this is either SCSI or IDE, and anyone worth their salt in the profession would know the technologies, and how to wire it up.

If you have a digital camera handy, perhaps taking a picture of the motherboard and of the drive bays would be helpful / useful. We need both because if you have IDE and master/slave relationships, they need to be wired properly. I am also hoping that you do not have too many drives, as if you wire them wrong, you might need to re-install OS X. If it is OS 9 related, I think the system will find the boot partion. Not sure.

As for your son, how did he get into your project room? Did you leave the computer wide open, inviting a curious child? Not trying to lecture you here... but if this was an iMac, or anything with a tube, he could have fried himself. A little physical security needs some review over there.

Let us know what you find out.

Christian

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