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Oobnoxious

macrumors newbie
Original poster
Jul 19, 2019
3
0
Hi Everyone,

First post long time lurker,

Long story short i Just got a hold of 4 old Macs + a monitor:

- G3 Beige Desktop
- Powermac 7200/200
- Mac Quadra 605
- MAc LC
Apple CRT monitor

I booted up the G3 by itself and the light came on and it seemed to boot fine.

Booted the monitor by itself. it made the usual suspect noises of a CRT that probably hasn't been turned on in over 20 years but it illuminated and the light turned on.

I then booted them together and i saw the post screen + splash screen turn on but then the monitor started buzzing big time and then the G3 powered of and no longer turns on???

I then, being a glutton for punishment (+ ignorant) repeated the process with the MAC LC ::facepalm::
SAME RESULT Now the Mac LC wont power either

This has me bamboozled because i dont see how the monitor could damage the mac's themselves .....

So my question to any savvy users is ... did i blow the PSU's on the Mac's or do you think i fried the MOBO's?

Or any suggestions like maybe i just tripped something and they will work after they have some alone time?

Thanks in advance,

Take Care,

Dan
 

MacTech68

macrumors 68020
Mar 16, 2008
2,393
211
Australia, Perth
Never heard or seen this before so I'll be guessing.

If the earth pin on the monitor's power cable is not connected to an actual earth, a discharge to chassis within the monitor MIGHT find a path to earth via the Mac video port.

At this point, i'd be removing the batteries from the LC and G3 motherboards, disconnecting them from AC mains and leaving them overnight. Check them again in the morning (without the monitor).
 

Oobnoxious

macrumors newbie
Original poster
Jul 19, 2019
3
0
Never heard or seen this before so I'll be guessing.

If the earth pin on the monitor's power cable is not connected to an actual earth, a discharge to chassis within the monitor MIGHT find a path to earth via the Mac video port.

At this point, i'd be removing the batteries from the LC and G3 motherboards, disconnecting them from AC mains and leaving them overnight. Check them again in the morning (without the monitor).

Thanks ill try this overnight tonight. I already tried taking out the battery and pressing what i think was either the CUDA or PMU reset switch. Nothing :(
 
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