Crap! Did I hose my motherboard....

Black&Tan

macrumors 6502a
Original poster
Mar 4, 2004
736
0
I was trying to install a second hard drive in my G4 MDD Dual 867, when the corner of the drive tray either brushed the motherboard or came close enough to arc. There was a bright spark and now there's a black burn mark on the board.

I ran TechTool Pro and everything appears to be okay. It passed all the tests with no issues. What other tests can I run to verify the stability of this machine?
 

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4JNA

macrumors 68000
Feb 8, 2006
1,505
1
looking for trash files
don't let the magic smoke out...

works, passed tests, i think you are fine.

the large green trace is a power trace, and it didn't look like the small 'through' traces to the left were affected.

i would make a good backup, go back to work, and keep an eye on that spot for a few days, that is look at it again in a couple days. if it's going to go, the spot will get bigger due to reduced trace capacity (same amount of power, now less trace, may decide to let go...). i also wouldn't leave the computer on overnight or when you are out for a few days just for safety. if you use it hard for several days with no problems/change, i think you are good to go.

best of luck.
 

Black&Tan

macrumors 6502a
Original poster
Mar 4, 2004
736
0
Thanks 4JNA! I'm still pissed at myself for what happened. I'm backing up now.... I'll definitely shut it down nightly, and keep an eagle eye on it. This is my work computer, so I need to be doubly careful. I don't want this to be the excuse IT uses to say we can't manage our own machines. Especially since they're not fluent in Macs!!!!
 

bartelby

macrumors Core
Jun 16, 2004
19,794
5
I know this may sound like a dumb question but,
You did have it disconnected from the power, when you were adding the drive, didn't you?
 

Black&Tan

macrumors 6502a
Original poster
Mar 4, 2004
736
0
No, I didn't have the power disconnected. In one of my previous jobs, the IT guru (he worked for a Mac supplier and repair depot) said to leave the power plugged in to ground the unit. In retrospect, it was a bad idea and he was probably full of it!
 

lostless

macrumors 6502
Oct 22, 2005
360
13
Your IT guy is an idiot. Im going for my A+ cert so all this is fresh in my head. First rule on working on a computer is unplug the power cord. Reason is that apple uses an ATX type power supply, which means power is always on, on the motherboard. Also applies to PCs as well. Grounding is good, but useless when you also have an active hot line running in the computer. Ground + hot = full circuit. You should of had a grounding strap plugged into a ground source (bottom plug on a wall outlet). But grounding yourself requires you have no power to the motherboard, otherise, you become part of the circuit. As fas as damage to your computer, i think you just sent it to slowly dying death bed. Not all ESD (electro static discharge) kill components, but wound them, maken them behave eratically. Dont be supprised if a few weeks down the road, yu start getting crashes, kernal panics, or the computer just shutting itself down. Good luck, I truly hope nothing was damaged. I hope this also has taught you a lesson about computer upgrades/repair.
 

4JNA

macrumors 68000
Feb 8, 2006
1,505
1
looking for trash files
lostless said:
...going for my A+ cert so all this is fresh in my head...
good stuff. out here in the REAL world however... the grounding thing is nice. if you have a dedicated bench, anti-stat surface/matt, and so on, you never have to worry. most of the computers in the world however are crammed under a desk sitting on crummy carpet. plugging something into a wall outlet, wrapping the other end around an arm, and then grabbing a piece of equipment is not what i would recommend to the average user...:eek:

unplug the computer (good tip), keep skin contact with the metal frame (pull up your sleeve, pull down your pants, get creative), then touch as many little parts as the job requires safe in the knowledge that you look really silly, but will likely do no harm.

like to see the A+ power off solution for finding the one fan that keeps making that really, REALLY annoying noise, but only when the case is closed...and powered on... oh, and i love the ITT commercials where the newly trained computer support person is wearing a tie and shiny shoes. lean over an open 2U case (power on as servers usually are...) with the tie on one time, i dare you.

trace damage. no chips were hurt. bet it runs fine until the next hardware upgrade cycle.
 

Black&Tan

macrumors 6502a
Original poster
Mar 4, 2004
736
0
You're right there, 4JNA. My CPU is under a desk, the wires for the battery backup run through portals within the desk, and there are two surge protectors also sharing the journey. Not much room, but that's a typical office environment. And I was continuously grounding myself with the with the frame, this was only the third time trying to set up this troublesome slave drive.... But the angle for inserting the hard drive bracket was "just" a bit too tight on the last try.

I'll post periodically with status reports....
 

bartelby

macrumors Core
Jun 16, 2004
19,794
5
4JNA said:
good stuff. out here in the REAL world however
And out here in the REALLY REAL world keeping power supplied to a computer while you add hardware is the dumbest thing to do!
 

lostless

macrumors 6502
Oct 22, 2005
360
13
I agree with the one person that talked about the real world. Just cause I'm becoming A+ cert does not mean Im the freaking genious in the computer world, or that I know better than anyone else. In fact I find the test kinda annying, memorizing somtimes stupid facts about old technology I havent seen since 1998. As for the strap, Ive installed many items without one, being very carefull, not to install in anyplace that has alot of static electricity. Anyway, My post was more of an electrical explanation. What I was trying to say is that he completed a circuit when he touched the metal chasis with a live line, even thogh at a very low voltage, on the motherboard. You should never work on a computer thats plugged in, period.
Have a nice day all.
 

yellow

Moderator emeritus
Oct 21, 2003
16,032
1
Portland, OR
Here in the real world, unless you're wearing a giant wool suit and actively building up a static charge, the unit should be unplugged and simply touching the power unit's metal case should be nough to discharge any static build-up you might have. For the first 5 years of my IT career I bothered with a static mat and wrist strap and all that crap.. well nearly 10 years later and countless hardware interactions.. no zapped hardware.
 

Bill Gates

macrumors 68030
Jun 21, 2006
2,500
14
127.0.0.1
All I've done since I began working on computers is ground myself on the PSU, then unplug. I've never had any issues doing this, and I don't wear a grounding strap or take any special precautions beyond not dragging my feet, etc..
 

tuartboy

macrumors 6502a
May 10, 2005
746
13
I'm no electrical engineer here (far from it), but how would a grounding wire complete an AC circuit? Doesn't the circuit run through the 2 non-grounded wires and not through the grounding wire?
 
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