Things were a little slow around the shop today, so I figured I'd tinker around with this Macintosh II that was given to me a couple weeks ago. It quit working (would no longer power up) in 1996, at which time they switched over to the PC platform. This old Mac has sat in the dank cold basement of a 100yr old storefront building for a local realtor's office ever since...so you can imagine what it was like down there....
I know nothing of Mac's other than the hundreds of G5 iMac and G4 eMac's I've recapped...... I plugged it in, pressed power, it wouldn't do anything....nothing. Common sense says to start in the power supply. Measured the PSU outputs, nothing, not even STBY. I removed it, took the cover off, blew out the almost 30yr old dust bunnies, and had a look... Starting in the primary, things were looking good. Fuses ok, rectifier diodes ok, no bloated/leaking caps, no red flags....so before I really start digging into it, I research the PSU model, which came up with a lot of obscure information on the entire Mac II system..... Apparently, these PSU's do not have standby voltage. When the power button is pressed, the initial powerup signal voltage is supplied by the CMOS battery, and once powered up, the +5v rail takes over and maintains the signal voltage....so I look at the motherboard and see 2x half AA size 3v batteries. One showed 3v, I was in shock that it was still good after all these years and stored in a cold place. The second one was dead as a mackerel... They were soldered to the board, so I cut them both off at the batt, leaving the leads in the board.
I had nothing like that laying around....but being 3v, a couple CR2032's would do just fine, atleast temporarily... I robbed a couple bad SX270 boards of their batt holders and soldered them in place and stuck new batteries in them.
ok, not the prettiest....but fine for testing purposes....
Putting it back together.......the ultimate "bigfoot" HDD, eat your heart out Goontron!! A whopping 80mb SCSI.
Low & behold, ignition!! The monitor really grumbled and groaned the first few seconds......between the degauss and all those old caps reforming, it made some really cool frankenstein lab noises. It booted right up.
There is no stripe in the display like the pic shows.... yay for low refresh rates and cameras.
Whopping 5mb of RAM....
That concludes today's lesson on how to waste an hour's time on a completely useless machine!!
I know nothing of Mac's other than the hundreds of G5 iMac and G4 eMac's I've recapped...... I plugged it in, pressed power, it wouldn't do anything....nothing. Common sense says to start in the power supply. Measured the PSU outputs, nothing, not even STBY. I removed it, took the cover off, blew out the almost 30yr old dust bunnies, and had a look... Starting in the primary, things were looking good. Fuses ok, rectifier diodes ok, no bloated/leaking caps, no red flags....so before I really start digging into it, I research the PSU model, which came up with a lot of obscure information on the entire Mac II system..... Apparently, these PSU's do not have standby voltage. When the power button is pressed, the initial powerup signal voltage is supplied by the CMOS battery, and once powered up, the +5v rail takes over and maintains the signal voltage....so I look at the motherboard and see 2x half AA size 3v batteries. One showed 3v, I was in shock that it was still good after all these years and stored in a cold place. The second one was dead as a mackerel... They were soldered to the board, so I cut them both off at the batt, leaving the leads in the board.
I had nothing like that laying around....but being 3v, a couple CR2032's would do just fine, atleast temporarily... I robbed a couple bad SX270 boards of their batt holders and soldered them in place and stuck new batteries in them.
ok, not the prettiest....but fine for testing purposes....
Putting it back together.......the ultimate "bigfoot" HDD, eat your heart out Goontron!! A whopping 80mb SCSI.
Low & behold, ignition!! The monitor really grumbled and groaned the first few seconds......between the degauss and all those old caps reforming, it made some really cool frankenstein lab noises. It booted right up.
There is no stripe in the display like the pic shows.... yay for low refresh rates and cameras.
Whopping 5mb of RAM....
That concludes today's lesson on how to waste an hour's time on a completely useless machine!!
Attached Files
(Or at best, 6 years)
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