Copied across from MacTalk Australia forums, written by myself, Michael aka. iMac600. Unlike over there you all probably remember my 512k with the fatal "FLUP" noise, and the defective logic board... well this is how that little Mac turned out.
Just over a month ago now, I arranged to buy up 2 old Compact Macs, one of which worked and the older of the two, a Macintosh 512Ke, was dead. Being an otherwise huge fan of the Macintosh (original) body shape and design, I bought it with the intention of correcting a minor voltage issue.
When it arrived, it was in pretty good shape externally. Internally it was the opposite. Age had taken its toll on the old Macintosh and left the internal frame looking a little rusty, the lower logic board cover stained with calcium, the floppy disk drive gummed up and the rest of it covered in dust. Not only that but neither of the two boards worked, both the logic board and the analog (power/video) board were dead.
Being a bit of a Mac nut that came from a background of restoring cars, I chose to begin restoring the old machine.
So obviously the first challenge was to make this thing actually switch on. When connected to mains and powered up, it would initialize the floppy disk drive over and over again while whistling... so it wasn't supplying the necessary juice to start the machine up, just enough to kick the floppy motor over.
Off to Jaycar to buy a new set of capacitors. Unfortunately the total of the capacitors was around $60 AUD... $47 of which was in 4 mains filter capacitors. So I just skipped them and bought the rest. In the end I needed to bite the bullet for the remaining 4 filter caps, so it has all new capacitors all around, but that was still not enough to kick it over. One last thing was holding it back...
...Flyback transformer. Although otherwise healthy and working, the solder joints around it were cracked. After desoldering and resoldering it, the 512Ke saw the light for the first time in many years.
I considered that a temporary success, being surprised to get even this far, and reapplied the glue to the new capacitors to prevent them from moving, as they do in the factory.
So... on to the Sad Mac. There was no error code, just garbage. I can only assume that this thing either had bad ROMs, but then I doubt it would fire up at all. So the culprit was bad IC's, which are not only near impossible to diagnose with home tools, but also difficult to find replacements for.
I had no idea where to go from here, so I turned to Byrd on the forums who happened to find another compact Mac, a Macintosh Plus, with analog board issues (cracked joints) and some case yellowing. I at least wanted one working Compact Mac. When it arrived, I noticed the case was indeed a nice shade of yellow on the front bezel and the analog board had a nasty habit of tripping the safety switches in my house.
However the logic board from the Plus did work in the 512Ke and did in fact tell me that the analog board restoration had gone well, so I pressed on in cleaning out the 512's floppy disk drive, cleaning up the internal frame and fitting the logic board from the Plus into the 512's body. (just like Apple's Macintosh Plus Upgrade kits).
Don't worry, the Plus wasn't left behind. I just need its logic board... for now. I'll still fix up that little fighter yet.
With the Plus upgrade hooked up and working in the 512Ke's shell, it now finally powered up to a blank grey screen. Getting somewhere now. Something was still holding up the boot process, but after some contact cleaning and fiddling with connectors, we finally had a flashing disk icon, an issue easily solved with one of these.
I can't remember how or where I got this, or who sold it to me, but whoever it was, thank you. It sure comes in handy now.
Although i'd managed to give it some video output, it still wasn't entirely right. The CRT was only displaying at half height and it was a little warped. So close now though, so I borrowed the electronics gear for a few hours to adjust the voltages and calibrate the display. A couple of hours later, the now Macintosh Plus 1MB powered up, accessed the system from the 800k floppy and after a month of working on it (factoring in diagnosis, parts availability and budget constraints), this old Mac works once again.
I find it a bit sad that the journey is now coming to an end. I still need a cable for the keyboard, but in reality that's all it needs to complete the kit. it even has an ImageWriter printer to go with it. That said, I also have plans for the Macintosh Plus that provided its logic board, either in the form of making a really killer System 7 or Mac OS 8 box inside it, otherwise i'll just upgrade it to a higher spec logic board and of course, restore the analog board. The journey begins again... (but there's no way i'm spending another $60 on capacitors, so thankfully the ones in the Plus are still good)
I think a complete shot is in order...
...showing off my pride and joy in all its glory. Going clockwise around the picture, we have the Macintosh, the ImageWriter printer, a box of Apple branded 400k and 800k floppies, an Apple 3.5" External Disk Drive, the Macintosh mouse and the Macintosh keyboard. I love this little Mac and intend to look after it for years to come.
Cheers
- Michael
Just over a month ago now, I arranged to buy up 2 old Compact Macs, one of which worked and the older of the two, a Macintosh 512Ke, was dead. Being an otherwise huge fan of the Macintosh (original) body shape and design, I bought it with the intention of correcting a minor voltage issue.
When it arrived, it was in pretty good shape externally. Internally it was the opposite. Age had taken its toll on the old Macintosh and left the internal frame looking a little rusty, the lower logic board cover stained with calcium, the floppy disk drive gummed up and the rest of it covered in dust. Not only that but neither of the two boards worked, both the logic board and the analog (power/video) board were dead.
Being a bit of a Mac nut that came from a background of restoring cars, I chose to begin restoring the old machine.
So obviously the first challenge was to make this thing actually switch on. When connected to mains and powered up, it would initialize the floppy disk drive over and over again while whistling... so it wasn't supplying the necessary juice to start the machine up, just enough to kick the floppy motor over.
Off to Jaycar to buy a new set of capacitors. Unfortunately the total of the capacitors was around $60 AUD... $47 of which was in 4 mains filter capacitors. So I just skipped them and bought the rest. In the end I needed to bite the bullet for the remaining 4 filter caps, so it has all new capacitors all around, but that was still not enough to kick it over. One last thing was holding it back...
...Flyback transformer. Although otherwise healthy and working, the solder joints around it were cracked. After desoldering and resoldering it, the 512Ke saw the light for the first time in many years.
I considered that a temporary success, being surprised to get even this far, and reapplied the glue to the new capacitors to prevent them from moving, as they do in the factory.
So... on to the Sad Mac. There was no error code, just garbage. I can only assume that this thing either had bad ROMs, but then I doubt it would fire up at all. So the culprit was bad IC's, which are not only near impossible to diagnose with home tools, but also difficult to find replacements for.
I had no idea where to go from here, so I turned to Byrd on the forums who happened to find another compact Mac, a Macintosh Plus, with analog board issues (cracked joints) and some case yellowing. I at least wanted one working Compact Mac. When it arrived, I noticed the case was indeed a nice shade of yellow on the front bezel and the analog board had a nasty habit of tripping the safety switches in my house.
However the logic board from the Plus did work in the 512Ke and did in fact tell me that the analog board restoration had gone well, so I pressed on in cleaning out the 512's floppy disk drive, cleaning up the internal frame and fitting the logic board from the Plus into the 512's body. (just like Apple's Macintosh Plus Upgrade kits).
Don't worry, the Plus wasn't left behind. I just need its logic board... for now. I'll still fix up that little fighter yet.
With the Plus upgrade hooked up and working in the 512Ke's shell, it now finally powered up to a blank grey screen. Getting somewhere now. Something was still holding up the boot process, but after some contact cleaning and fiddling with connectors, we finally had a flashing disk icon, an issue easily solved with one of these.
I can't remember how or where I got this, or who sold it to me, but whoever it was, thank you. It sure comes in handy now.
Although i'd managed to give it some video output, it still wasn't entirely right. The CRT was only displaying at half height and it was a little warped. So close now though, so I borrowed the electronics gear for a few hours to adjust the voltages and calibrate the display. A couple of hours later, the now Macintosh Plus 1MB powered up, accessed the system from the 800k floppy and after a month of working on it (factoring in diagnosis, parts availability and budget constraints), this old Mac works once again.
I find it a bit sad that the journey is now coming to an end. I still need a cable for the keyboard, but in reality that's all it needs to complete the kit. it even has an ImageWriter printer to go with it. That said, I also have plans for the Macintosh Plus that provided its logic board, either in the form of making a really killer System 7 or Mac OS 8 box inside it, otherwise i'll just upgrade it to a higher spec logic board and of course, restore the analog board. The journey begins again... (but there's no way i'm spending another $60 on capacitors, so thankfully the ones in the Plus are still good)
I think a complete shot is in order...
...showing off my pride and joy in all its glory. Going clockwise around the picture, we have the Macintosh, the ImageWriter printer, a box of Apple branded 400k and 800k floppies, an Apple 3.5" External Disk Drive, the Macintosh mouse and the Macintosh keyboard. I love this little Mac and intend to look after it for years to come.
Cheers
- Michael
