The Mac Pro First Generation is an Intel Xeon-based workstation computer manufactured by Apple Inc. The first generation model includes the machines from 2006 through 2008.

264 Questions View all

Powers On but No Video

I recently came across what seemed like a good deal on a handful of 2008-era Mac Pro desktop machines. Of the three I picked up, one turned out to be a dual-processor G5 machine, and the other two are dual-processor Xeon machines. The Xeon machines are the ones I'm trying to resurrect.

None of the machines had hard drives or video cards. I bought a couple of new hard drives and a couple of new (MSI F5450 MDIGH) video cards, installed one of each into each of the two Xeon machines, and pressed the button.

Both machines turn on and the power lights are on steady. But I get no video from either machine (I have two monitors plugged into each - one via HDMI and one via VGA). I don't understand why I'm not getting any video (and no video is making it hard to troubleshoot anything else). Is it because there's no drivers on the brand-new hard drive?

For what it's worth, I opened up the case and started each machine, and I see no LED indicator lights anywhere inside (I think there are supposed to be some, but I don't know where).

Today, I connected my MBP to one of the machines via Firewire and started the Pro in Target Disk Mode. I immediately got the "The disk you inserted is not readable..." dialog on the MBP and used Disk Utility to format it. Then ran OS X installer and installed Yosemite on the newly-formatted HD in the MP. Unplugged everything and restarted...still nothing.

Any ideas on what's going on here?

Answer this question I have this problem too

Is this a good question?

Score 3

Comments:

Any chance you can give us the last four digits of the computers serial number? That would help us to determine exactly what hardware they are supposed to have. what memory modules are you using? Which slot did you install the video card in?

by

Last four digits of SN of the machine I have here at home are "AUQ2". (Other machine is still at my office.) There are four 2GB RAM modules in this particular machine, two installed in the top two slots of each daughtercard (per the manual). Video card is installed in Slot 1 (farthest away from hard drives).

by

3.0 GHz Q. Core Xeon X5365 x2

Intro. April 4, 2007* Disc. January 8, 2008

Order BTO/CTO Model A1186 (EMC 2138)

Family Mac Pro ID MacPro2,1

RAM 1 GB VRAM 256 MB

Storage 250 GB (7200 RPM) Optical 6X DL "SuperDrive"

by

Andrew Taylor, can you please verify the EMC number being 2138 since that with a dual Xeon would make it a Mac Pro 8X and slightly different layout for the diagnostic LED's

by

EMC is 2113.

by

Add a comment
Deck the Halls
With tools and Fix Kits

5 Answers

Most Helpful Answer

Andrew Taylor, here are a couple things that may help to further trouble shoot:"

Power-On Self Test: RAM and Processor Verification

A power-on self test in the computer’s ROM automatically runs whenever the computer is started up after being fully shut down (the test does not run if the computer is only restarted). If the test detects a problem, the status LED located above the power button on the front of the computer will flash in the following ways*:

1 Flash: No RAM is installed or detected. Or, the quick memory test failed. An LED will light up on the memory riser card next to the affected DIMM or empty DIMM slot.

3 Flashes: A RAM bank failed extended memory testing. An LED will light up on the memory riser card corresponding to the affected DIMM.

Troubleshooting: Try reseating the memory DIMMs. Check memory installation instructions for proper installation order. Swap affected DIMM with known good DIMM.

*Note: The status LED lights up when the power button is depressed at startup. Do not count this light as one of the diagnostic flashes. The memory riser card diagnostic LEDs will also flash briefly when the computer is started up or shut down and when it goes in and out of sleep mode. This is normal behavior.

  • Diagnostic LEDs

Logic Board Diagnostic LEDs

The Mac Pro (Early 2008) logic board includes a set of LEDs to help service providers troubleshoot the computer. The LEDs are located on the logic board between the two DIMM riser card connectors. LEDs 3, 4, 5, and 6 are normally off and will automatically illuminate if an error occurs. To read LEDs 1, 2, 7, 8, and 9, you must press the DIAG_LED button, which is adjacent to the LEDs. To press the DIAG_LED button, use the nylon probe tool (Apple part number 922-5065).

Block Image

Block Image

Mac Pro 8X

Block Image

LED 1 Sleep

LED 2 Standby or Trickle Power

Normally on when DIAG_LED button is pressed.

If LED 2 is not on, the symptom would be that the computer won’t power on.

Troubleshooting:

Check AC cord is connected to a working AC wall outlet.

Reseat AC Plug.

Check connections of power supply cables to the logic board.

Check power supply cable connections at power supply.

Replace power supply.

LED 3 CPU B (Lower Processor) Error

LED 4 CPU A (Upper Processor) Error

Normally off. These LEDs come on if an error occurs or if the BootROM is corrupted. They do not depend on the DIAG_LED button being pressed.

Related symptoms include no video or the computer is hung up. If the BootROM is corrupted, the optical drive tray should eject, prompting for the insertion of a recovery disc to restore the BootROM.

Troubleshooting:

With the computer booted, up press the SYS_RST switch. If this clears the CPU Error LED, check for incompatible device driver software that may have been installed for added hardware.

If the Error LED is still on, power down the computer and try resetting the SMC. Restart the computer.

Reset the power supply by unplugging the AC cord for 10 seconds.

Unplug AC cord and remove any added DIMMs and PCI Express cards. If this causes the LED to go off, repopulate the DIMMs and/or PCI Express cards to find the combination that caused the LED to come on. Overheated memory could be a possible cause for this CPU error LED to come on. Check fan operation.

Unplug the AC cord and remove the battery for 10 seconds. You may need to remove a PCI Express card to get to the battery. Reinstall the battery and restart the computer.

Try swapping CPU A and CPU B locations. If the CPU Error LED follows the CPU, replace that CPU.

Try replacing the logic board.

LED 5 CPU B (Lower Processor) Overtemp

LED 6 CPU A (Upper Processor) Overtemp

Normally off. These LEDs come on if an error occurs. They do not depend on the DIAG_LED button being pressed.

These two LEDs can operate in two different modes; they will either flash or stay on. If either LED is flashing, it may indicate an initial processor over-temperature condition. If either LED is solidly on, it may indicate a chronic processor over-temperature condition. Initial processor over-temperature can cause symptoms such as sluggish computer performance. Chronic processor over-temperature can cause the computer to hang completely.

Troubleshooting:

Verify proper heatsink installation.

Verify all thermal sensors are properly connected.

Verify all fans are operating properly, especially the front intake fan.

Verify power supply cables are properly seated.

If both overtemp LEDs come on immediately when the computer is turned on, a faulty power supply could be one cause of this behavior. Replace power supply.

Try swapping CPU A and CPU B heatsink locations. If the CPU Error LED follows the CPU

heatsink, replace that CPU heatsink.

Try swapping CPU A and CPU B locations. If the CPU Error LED follows the CPU, replace that CPU.

LED 7 GPU Present

Normally on when DIAG_LED button is pressed.

If this LED is on, it indicates there is a graphics card installed and recognized by the computer. It does not indicate that the graphics card is fully functional. Some graphics cards require additional power to function, which is available from connectors on the logic board. For these cards, if the auxiliary booster power cable is not connected between the logic board and the graphics card, an error message reminding about this additional power connection will be displayed as Mac OS X starts up.

Troubleshooting:

Check that the graphics card is seated correctly in its PCI slot.

Check that the card’s auxiliary booster power cable is connected properly on both ends (if the card requires one). If the cable is connected properly, try connecting it to the other, empty logic board booster power connector (if available) to see if the cause is related to this connector. If the card and LED operate properly when connected to the other power connector, check EFI and SMC firmware versions and update them if necessary. See “Mac Pro Firmware Updates” in this section for more information. Only then should you consider replacing the logic board.

Verify power supply cables are properly seated .

Try the graphics card in a different PCI slot.

Try a different graphics card.

If an error message about graphic card booster power connection is displayed, check that the appropriate booster power cable is firmly connected between the logic board and the graphics card.

Replace the logic board.

Replace the PS3 power supply cable. (• Note: This cable supplies power to the PCI slots.)

LED 8 Power Good

Normally on when DIAG_LED button is pressed.

If this LED is on, it indicates the power supply is functioning.

Troubleshooting:

Check that the power cables to the logic board are properly attached.

Check the cable connections at the power supply.

Check for any signs of an obvious electrical short, e.g. metal screws or PCI card slot cover loose inside computer touching the logic board.

LED 9 EFI Good

Normally on when DIAG_LED button is pressed. Takes approximately 5 seconds after power up.

If this LED is on, it indicates that the computer has completed the on board Extensible Firmware Interface (EFI) operations and the operating system is now in control.

Troubleshooting:

Check that LED 8 Power Good LED is on.

Check that LEDs 3, 4, 5, and 6 are off.

Try removing any added hardware.

Try removing any added DIMMs.

Memory Riser Card Diagnostic LEDs

Both of the memory riser cards include diagnostic LEDs for each DIMM. Each of the LEDs will light if it detects an issue with the corresponding installed DIMM. These LEDs will also flash briefly when the computer is started up or shut down and when it goes in and out of sleep mode. This is normal behavior.

Troubleshooting:

Shutdown and restart the computer.

Verify EFI and SMC firmware versions and update them if necessary. See “ Mac Pro Firmware Updates” in this section for more information.

Reseat the memory riser card associated with the failure LED. If the failure LED persists, continue with the next step.

Swap upper and lower memory riser cards A and B. If the symptoms follow the riser card, continue with the next step. If the failure LED remains associated with the same memory riser card slot, consider a possible connection issue with the logic board. Replace the logic board in this case.

Reseat the appropriate DIMM corresponding to the failure LED. If the issue persists, continue with the next step.

Check memory installation instructions for proper installation order.

Swap affected DIMM with known good DIMM.

Try moving DIMM to another slot (within the same bank of two) to see if the failure LED follows the DIMM. If so, replace DIMM with known good DIMM. If the failure LED persists, replace the memory riser card associated with the failure LED.

Video Card Diagnostic LEDs

T_Fault LED

Normally off, this LED lights up if the graphics chip gets too hot.

Troubleshooting:

Verify that the video card heatsink and fan are not clogged with dust. Carefully blow out any dust as necessary.

Check that the front fan is working.

Try re-seating the card in the PCI Slot.

Make sure the card’s auxiliary booster power cable is connected (if there is one).

Re-boot the computer.

Mac Pro (Early 2008) Troubleshooting — General Information 159

Try a different video card.

Replace the video card.

Ext_Power LED

Normally off, this LED lights up if the auxiliary power isn’t being supplied.

Troubleshooting:

Make sure the card’s auxiliary booster power cable is connected (if there is one).

Check connections from the power supply to the logic board.

Try a different auxiliary power cable.

Try a different video card.

Replace the video card.•

Power Supply Verification

To power on, the computer’s logic board requires “trickle” power. If the system fails to power on, first reset the SMC as described in this chapter. If the computer still doesn’t power on, follow the procedure outlined below to determine whether the issue is related to the power supply.

Verify trickle power

Diagnostic LED 2 indicates the presence of trickle power required by the logic board to begin the startup process.

LED 2 should be yellow when the DIAG_ LED button is pressed, indicating that trickle voltage is present.

Verify Power Supply Is Providing Power

Diagnostic LED 8 indicates that the main power is OK and within regulation.

Plug in AC power cord, and press the power-on button on the front panel.

LED 8 should be green when the DIAG_ LED button is pressed, indicating that the main power is OK and within regulation.

If diagnostic LED 5 and LED 6 are both solidly illuminated at power up, improperly seated power supply cables could be one cause of this behavior. Check all power supply cable connections to ensure they are properly seated.

Was this answer helpful?

Score 3

Comments:

Wow...I just have to comment after seeing this post. oldturkey...I have always enjoyed reading your recommended solutions. Knowledge is power and you my friend have got a lot of it. Kudos to you!

by

"Try replacing the logic board."

That's funny. Like, my wife says "my car won't start," and I say "try replacing the engine."

Otherwise, that looks like a promising stack of instructions. I'll have to sit down with my laptop and the dead machine tomorrow and go through that whole post.

by

Sounds like a plan:-) and stop just short of replacing the logic board

by

Okay, I had some time to troubleshoot this morning. With the video card installed in PCI Slot 1, pressing the DIAG_LED button lights up LEDs 2 and 8 - nothing else, including the GPU_PRESENT LED. Moving the video card to the other PCI slots (tried them all) results in no change. Replacing the video card (tried all 4 slots) results in no change. So...there's either a problem with the two video cards I bought (they're identical), or a problem with the Mac itself. I've ordered a Mac-specific video card off eBay (Nvidia GeForce GT 120) that was apparently pulled out of a similar Mac Pro unit and is "guaranteed to work". We'll see.

by

New graphics card was a bust. It doesn't work in any of the slots on the machine. Still not getting "GPU-Present" LED on any slot. Methinks the logic board is busted.

by

Show 1 more comment

Add a comment

Hey Andrew,

Sounds like your Mac Pro is starting up properly but its not reading any drivers for your Graphics Card. Here is a link to the specifications for that Mac Pro if your right on the money about what year/gen it is: Mac Pro (Early 2008) Specs. Take a look at the specs for the graphics card and grab one that matches those specs. From experience, a friend of mine had somewhat of a similar problem if I can recall correctly and the Graphics card that ended up working was an ATI Radeon HD 4870. Hope this helps.

Best of Luck!

Was this answer helpful?

Score 2
Add a comment

Andrew,

did you get anywhere with your computers?

We are a company that refurbs older Mac Pro's and a Top Seller on EBay...

From the posts, you may have several issues...

*the memory may be in the wrong slots - from what i read in your posts is that the memory is in the top slots of the memory risers...

Mac Pros like their memory in the bottom slots (the ones closest to the edge connectors)

*your choice of video cards may be problematic as others have suggested - a great generic video card for the 2008s is the ATi XT2600 - very good card and not too expensive OR use an NVidia 120GT (from the 2009 MPs) - you will not get a splash screen with NON-Apple video cards - this can cause you much stress as it may take several minutes for the computer to start with no video output until the last moments.

*you may have old dust and such causing shorts and general confusion on the board - if you have not broken it down we would recommend that you do so and clean it all (compressed air and small soft brushes works great) - including the power supply.

  • In taking it apart you will discover things like wrong CPUs on the board (or no CPUs on the board) - we have seen may unusual things...

If we can help, let us know as we help our customers all the time - we may not always have the answer, but we will do our best to find the answer for you...

Was this answer helpful?

Score 1
Add a comment

Actually, I got both machines working, and they've been humming along just fine for several months now. The trick turned out to be getting the correct video cards installed. I found a guy locally who had a couple of Nvidia cards out of the original machines. About $65 each, and I was off and running.

These things really hum. Even the "slow" one is pretty spiffy - my son is upstairs playing Doom III on it right now without a glitch.

Was this answer helpful?

Score 1
Add a comment

I'm reposting my comment as an answer because I don't think comments trigger an email notification to those of you who might be subscribed to this topic (they don't for me, anyway)...

New graphics card was a bust. It doesn't work in any of the slots on the machine. Still not getting "GPU-Present" LED on any slot. Methinks the logic board is busted.

Looks like I can get a replacement logic board on eBay for about $80 - but I don't want to go throwing good money after bad. Can any of you confirm that a faulty logic board would cause the symptoms I've indicated?

Was this answer helpful?

Score 0
Add a comment

Add your answer

Andrew Taylor will be eternally grateful.
View Statistics:

Past 24 Hours: 5

Past 7 Days: 68

Past 30 Days: 287

All Time: 5,774