DEAD MAC PRO 1.1 LOGIC BOARD AFTER INSTALLING A PCI EXPRESS VIDEO CARD

Question

DEAD MAC PRO 1.1 LOGIC BOARD AFTER INSTALLING A PCI EXPRESS VIDEO CARD

Two months ago I was given away a Mac Pro 1,1 (A1186), in perfect working condition. Some days later, I had the bright idea of testing a working PCI express video card I removed from a PC on my Mac, but it didn’t turn on. So I removed the video card, reinstalled the old one, and again, it didn’t turn on. I removed the 3v battery to reset the PRAM, replaced it with a new battery, performed a SMC reset, and tried everything I read on the forums, with no luck. I checked the logic board status led’s and I noticed they all remained off. Then, suspecting that the culprit was the PSU, I ordered a second-hand one on eBay (Delta DPS-980AB A), I installed it yesterday but my Mac still doesn’t turn on. No lights, no clicking sound (relay), no spinning fans. I checked all the connectors again. I tested it by unplugging connector # 4 and shorting ‘PS_ON’ plug and ground either a paper clip. A click is produced, the PSU switches on, all the fans start spinning, all the LED’s on the RAM raiser light up, but the logic board LED’s don’t light up, the switch-on button doesn’t respond and as soon as I remove the paper clip, the PSU switches off. Conclusion: the “new” PSU works fine, so does the old PSU (I tested the voltages on both of them), and my logic board is toasted, I’m afraid. Is there any “miraculous” procedure to revive my Mac, or I have to buy a second-hand logic board?

Posted on Sep 30, 2024 11:22 AM

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Answer 1

OldGoat67

Level 2

392 points

Sep 30, 2024 1:23 PM in response to JAVI_El_LARGO

Hola, Javi_El_Largo

i’d recommend you read and use the Mac Pro technician guide for your model of Mac Pro… I can’t really post links to it here, but I know it’s on Facebook somewhere ( MacPro FB Group) it’ll help you and explain some stuff.., help with troubleshooting and diagnostics… Obviously don’t take it to a n Apple Store with Genius Bar- it’s way too old for them

to work on+ they don’t have the parts…AASP’s are out too for the same reason unless you want to spend a LOT of money ( I’m guessing not) … so, get that guide, contact that Facebook Group, they could help you better then I could… just for a laugh I looked up the price on eBay- used board is $250-ish, a new one is $400-ish

john b

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Answer 2

OldGoat67

Level 2

392 points

Sep 30, 2024 6:39 PM in response to JAVI_El_LARGO

! yo soy tan Cansado ¡

olá, it’s me again … John…

my Spanish is okay, but I’m tired, so English…

you will need to find a Pinout diagram of the Mac Pro power supply plus a multimeter/voltmeter.. the diagram should have the pins there and which voltage each pin should supply… I think it’s DC volts ( could be AC) .. anyways plug the poewer supply into the wall and carefully measure the voltage on each pin… check the diagram… if the voltages you measure on each pin match up to the ones in the diagram, then the power supply is working fine… the problem must be elsewhere…so, iFixit, the Facebook group and even googling Mac Pro 1,1 repair might help you a bit… I am no Mac expert or even a trained Mac Pro technician, just a passionate ( so would say crazy) Mac user… Spain sounds lovely… I love Spanish food, especially your Machego cheese… but it’s very expensive here in Canada ( Canadian cheese tax) .. $11 for 150 grams of Manchego… so it’s a nice luxury for me..

anyways, Buenos Noches Señor ,..

I go sleep now

John B

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Answer 3

Sep 30, 2024 1:50 PM in response to OldGoat67

Hi John, I downloaded a copy of Apple’s Service Source manual for Mac Pro, the official service manual, but it didn’t help much. I’ll follow your advice and look for help too in the FB group you mentioned.

Yes, I know the parts for these old Macs

are very expensive, and it’s very hard finding them in Europe, so if the logic board is faulty I’ll have to order it from USA.

Thank you.

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Answer 4

OldGoat67

Level 2

392 points

Sep 30, 2024 2:39 PM in response to JAVI_El_LARGO

Ok- the Mac Pro technician guide should have some basic troubleshooting things in it, eg what the LED’s inside you Mac Pro mean when they are lit up( or not) … plus there’s a little button you have to press around there when it starts up which tells you more things… iFixit might help somewhat? That eBay listing I mentioned for a new 1,1 logic board was from Germany, and the price was in Canadian Dollars..I checked the UK eBay site and they’re asking £ 175 + £40 postage… it’s been opened, never used, so I guess it’s new it’s 34, 866 Spanish pesetas, and 7,969 pesetas for postage… I don’t know where you’re from in Europe exactly, so hopefully some of the currency numbers you can use, eg, convert it to your local currency… I don’t know how much more help I can be… I tried

john B

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Answer 5

Sep 30, 2024 4:13 PM in response to OldGoat67

Hi again.

You’re right, the Apple Service Source manual explains the meaning of the logic board LED’s and the operation of its push buttons. I’ve reading the troubleshooting chapters thoroughly. My problem is that those LED’s don’t turn on, no matter what I do. After browsing IFixit and many forums, I still haven’t found a solution.

Since you mentioned it, I live in Spain, and our currency is Euro = €. That board would cost about €194.

If I eventually buy a logic board –the most likely– I’ll check the eBay listing you recommended.

I greatly appreciate your help.

Greetings from sunny Spain.

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Answer 6

Sep 30, 2024 4:56 PM in response to JAVI_El_LARGO

We reference eBay prices because in the US, a big country with no Tariffs between States, US eBay is the definition of a "fair market" -- a term used often to describe a place where lots of buyers and sellers converge to trade goods, where neither is compelled to buy or sell.

Not necessarily because that is a good place for an individual to actually buy or sell.

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Answer 7

Oct 1, 2024 2:15 AM in response to Grant Bennet-Alder

I’m not criticizing eBay, and I don’t feel compelled to buy on eBay. In fact, bought the Mac Pro PSU on eBay.

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