HIS 7950 not allowing 4.1>5,1 cMP to startup

[MIKX]

I've had my HIS 7950 stored away during this hot summer and have been using a HIS 5870 ( both cards are flashed).

Last week, I finally got the correct cables for a recently bought Sapphire DUAL-X 7970 which has been running perfectly.

The problem :
This week as we still have hot & humid weather here in Japan I removed the 7970 and I decided to go back to the HIS 7950 in slot 1.
Connected the two original 6 pin to pin Apple supplied cables back into the MB sockets, installed the HIS 7950 to PCIe slot 1 x16 . .. connected the two monitors usually connected with the same cables previously used, the BIOS switch is still in it's original working position. Used the previously working video cables setup

The cMP would not even start ! Pressed the power button = nothing.

I tried it out in both slot 2 & slot 4 .. cMP will not startup.

Disconnected the power cable from the cMP for 5 minutes and then did a PRAM reset .. . the cMP would still not power on with the 7950 installed in any pcie slot.

I find it hard to believe that this 7950 could fail so suddenly, it has never been over stressed and has always been correctly powered ( 2 x onboard 6 pin ).

Since I first removed the HIS 7950 for ( non-static ) storage is has not been touched at all intil tis week's installation

It is possible that the problem is with my PCIe ports ?

How can a previously working perfectly PCIe GPU cause the cMP not to even start up ?


All & any advice, similar experiences, solutions wil lbe accepted with gratitude ( I love this 7950 ! )

 

[tsialex]

Did you check for condensation, shorts, etc on the HD 7950? After testing with the HD 7950, your Mac Pro worked back with the HD5570?

 

[MIKX]

Did you check for condensation, shorts, etc on the HD 7950? After testing with the HD 7950, your Mac Pro worked back with the HD5570?

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EDIT ( the HIS 7950 card has often been de-dusted, never exposed to overheating and was stored in a non-static bag .. has never been dropped while in my possession. )
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Thanks for your swift reply !

It currently works with the Sapphire 7970 X16 in slot 1 5.0 GT/s

.. but when I installed two different HD 5870's ( HIS & Sapphire ) they showed LINK WIDTH of x 8 . . previously they showed X 16.

It feels like it's a PCie slot problem. Can one " re-set PCIe slots ?


My bootrom = MP51.0089.B00 ( booting from a M.2 960 EVO.

My PCIe slot set up.

Slot 1. x 16 = HD 7970

Slot 2. covered by the HD 7970

Slot 3.M.2 adapter with 960 EVO

Slot 4. SATA powered USB 3.0 4 port fully populated.

 

[tsialex]

Try to clean your slot with IPA and a de-oxidant spray.

Check if the spray attacks plastics first, some destroy some types of plastic.

 

[MIKX]

I don't want to use IPA in my motherboard PCIe slots .. too scared and slot 1 is working with my currently installed HD 7970.

But I have just pulled the HIS 7950 apart and have cleaned every surface, PCIe contacts etc. with IPA .. I'll leave it to dry out for 24 hours and try it in the cMP again with new thermal paste.

 

[MIKX]

I also totally cleaned, de-dusted & applied new thermal paste to my HIS HD 7950 IceQ .. plugged it into PCIe slot 1.
Pressed the cMP power button .. . .

NOTHING .. no startup​

Disconnected power, removed the HIS 7950.



I then totally cleaned, de-dusted & applied new thermal paste to my HIS HD 5870 which previously was showing a Link Width of X 8 in PCIe slot 1 ..

Hit the power button . ..

Voila ! ​

it now shows " X 16 @ 5.0 GT/s as it used to.

I can only surmise that something crucial has failed on the HIS IceQ HD 7950 which is a real shame as this card has by far the most efficient cooling I have come across.

Off topic : Does anyone know if the MSI Gaming R9 280X 3 gb allows access to PCIe slot 2 ?
[doublepost=1537078367][/doublepost]My next step will to see if the HIS IceQ 7950 works in a Win PC. If it does .. what does that tell me ?

Crazy thought : Is it possible that the combination of my MP51.0089.B00 bootrom with an M.2 adapter in PCIe slot 3 is causing PCIe power conflicts or has anything to do with the boot up failure ?

If the 7950 boots in a Win PC I'll report back.

If it doesn't boot I'm off shopping for a 2 PCIe slot R9 280X ( The MSI Gaming R9280X looks like a 2 slot )

The 7950 2 slot allowed me to use slot 2 for a nice & reliable ( Japanese made ) USB 3.1 card.

My Sapphire DUAL-X 7970 is nice but covers slot 2.

 

[weckart]

Off topic : Does anyone know if the MSI Gaming R9 280X 3 gb allows access to PCIe slot 2 ?

If you mean the Twin Frozr then you have access to slot 2 but it will block one of the intake fans. I've taken a pic of mine so you can see.

 

[MIKX]

weckart

Thanks so much ! That confirms it for me. That will be my next card.

 

[MIKX]

weckart

Does it have the 2 bios switch ?

Have you EFI flashed it ?

Is it running at 5.0 GT/s ? ( if it is a reference card this is easy to do )

Are you happy with the card ?

 

[weckart]

weckart

Does it have the 2 bios switch ?

Have you EFI flashed it ?

Is it running at 5.0 GT/s ? ( if it is a reference card this is easy to do )

Are you happy with the card ?

Yes, yes, yes and yes, so far.

With regards to the card, I don't really game with or push it. I only got it because it came up when I needed to replace my HD7950 that was dying. Because all of my HDD slots are taken, I had to do a Pixlas mod to power it. (6+8 pins). I haven't repasted it yet but it sailed through all the benchmarks except Furmark, where it crashed as temps went over 84ºC, so there is room for improvement there.

If you want to tinker, there seem to be plenty of firmware updates on TechPowerUp. You can try all of those before flashing with the Mac EFI.

 

[MIKX]

After I got my Samsung M.2 NVMe 960 booting High Sierra i removed all internal spinner HDD'S and put 2 big enough SSD drives in the DVD compartment .. I now have all the important data on those internal SSD's. Less important stuff goes on a 4 tb spinner drive connected to a PCIe USB 3.0 dock.

Without the spinners internally installed there is more throughput for the cooling fans . .also . .I think SATA II is obsolete.

Right now here in( still ) hot & humid Japan my I have a remote temp sensor showing my internal temp behind the CPUs at around 31°C with the side panel on.