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Killed my Beige( Lobo trouble shooting steps? ).
Posted by: DarthNvader on 2025-01-29 11:10:18
The Power Supply ticks on when jumped, but no power when connected to the Logic Board.

I removed everything from the logic board and power supply but the 20 pin PS to LoBo, ROM SIMM, VRM, and CPU.

Logic board is not tripping the PS on.

VRM looks good, but I don't know exactly how to test it with a multi meter?

Jumper by the PCI slots for Mac or ATX is present and in the correct position.

CPU/Bus/PCI Bus jumper all look good.

Will the Beige power on the PSU if the CPU went out, or without the CPU installed?

I was reading the properties of a PCI card in OF, and I shut the machine down. Installed a different PCI card in that slot, then tried to power it back on, and just nothing.

I removed all PCI cards and the Personality card.

No Ram in the system at this time.

Any ideas?
Posted by: DarthNvader on 2025-01-29 13:33:02
Got it working again, set the PSU jumper to ATX, then back to Mac and now it's woking fine.

Maybe I bumped it when I was swapping PCI cards....
Posted by: Trash80toHP_Mini on 2025-01-29 19:47:43
Good work, was checking thread to see if you needed a board, glad you don't. Stuff happens.
Posted by: DarthNvader on 2025-01-30 00:36:14
Good work, was checking thread to see if you needed a board, glad you don't. Stuff happens.
I always need a Beige board;-)

Found a bad stick of RAM too....
Posted by: GorfTheChosen on 2025-01-30 06:52:21
I was reading the properties of a PCI card in OF, and I shut the machine down. Installed a different PCI card in that slot, then tried to power it back on, and just nothing.

You pulling the AC power cord to the PSU while you're doing that PCI card swapping ?
Posted by: DarthNvader on 2025-01-30 07:01:36
You pulling the AC power cord to the PSU while you're doing that PCI card swapping ?
No, I did not, but I never do, could have been the issue tho....
Posted by: GorfTheChosen on 2025-01-30 07:10:05
No, I did not, but I never do, could have been the issue tho....

Have been pretty lax about it myself over the years ... but I've gotten more cautious about it lately ... particularly with all the funkiness I've seen on the two Power Surge machines.
Posted by: croissantking on 2025-01-31 04:44:52
Have been pretty lax about it myself over the years ... but I've gotten more cautious about it lately ... particularly with all the funkiness I've seen on the two Power Surge machines.
Is there a +5V trickle to the PCI slots?
Posted by: DarthNvader on 2025-01-31 05:40:42
Is there a +5V trickle to the PCI slots?
I hope not!

I never unplug my Mac's switching PCI cards unless I'm swapping the AGP card in ADC Macs because that little dohicky by the ADC connector is always hot and you will hit it with the faceplate of the AGP card.

Pretty sure it's 28v and I know for a fact it will throw a hell of a spark show.
Posted by: croissantking on 2025-01-31 06:34:02
I hope not!

I never unplug my Mac's switching PCI cards unless I'm swapping the AGP card in ADC Macs because that little dohicky by the ADC connector is always hot and you will hit it with the faceplate of the AGP card.

Pretty sure it's 28v and I know for a fact it will throw a hell of a spark show.
You can get a spark even from 5V, as I discovered the other day whilst twiddling with the ROM SIMM of my powered-on SE/30. Gave me quite the fright, but no damage seems to have been done.
Posted by: GorfTheChosen on 2025-01-31 07:40:54
Is there a +5V trickle to the PCI slots?

... certainly not with the power cord unplugged ?

Seriously though, I have no idea ... and, from what I've seen of your posts, I'm guessing that you have a far better idea about the actual answer to that question than I.

Here's what I do know though:

Every Apple manual for a Power Mac that I have says to unplug the power cord before installing PCI or Nubus cards.

I didn't design or build them ... and I'm not an engineer ... but if my car's manual calls for Dexron ATF for the transmission I'm probably not going to put in Type F.

I'm just kinda funny that way ... 😉
Posted by: DarthNvader on 2025-01-31 08:34:42
I've never killed a Mac swapping PCI cards, and I'm willing to wager I've done it more time than the top three behind me combined.

Like I said, AGP is another matter when it has ADC.

Keeping the 3 prong power cord installed keeps the Mac grounded, so you touch the grounded metal on the Mac and you discharge the static.

There is more chance of you not using a grounded wrist strap killing the PCI card or the logic board because you are not grounded!
Posted by: croissantking on 2025-01-31 12:43:54
and, from what I've seen of your posts, I'm guessing that you have a far better idea about the actual answer to that question than I.
I’ll take that as a compliment 😀
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