HP Z600 won't boot with matched pair CPU added

[Sketchup]

I have been running only one xeon x5660 while I waited for my second heatsink to arrive. Today I installed the second CPU with heatsink but sadly It wasn't smooth sailing like the first CPU.

My first issue was that I was running kingston 3x8gb with HP OEM 3x2gb but they don't have the same voltage so there was no power up. I reduced to two 8gb in each DIMM1 slots and made progress.

Once the computer turned on, the HP invent logo appeared on my screen but that's where it gets stuck, there is no beeping yet no BIOS or boot occured and the f8/f9/f10 option are written.

The computer is stuck powering on.
Note I have not had a chance to switch things up and test what (second CPU or new heatsink) is the issue. the new heatsink is the OEM HP part for the z600.

[iMaxx]

You made mention of mixing RAM. That will cause a problem.

The RAM that is in there now, is it HP registered RAM? (Even on the CPU riser board?)

[Sketchup]

Yes the RAM that is currently there is ecc reg and works (I've been using it for a few weeks) the mixing was an issue.

[iMaxx]

Ok let Me dig about and see what I can find.

Ran is installed on the riser card with the new CPU though, yes?

[Sketchup]

no the z600 has no riser that I'm familiar with, I believe it's the z620 that has it...

I think I found my problem

http://imgur.com/a/jIos5

you can see thermal pasted seaked down to the socket, hopefully cleaning this carefully will save my life

[iMaxx]

Ah yes. You're correct.

That paste may be the issue.
Then it very carefully. Silly fragile pins.

[SDH]

Oooo, too bad.    What type of paste was that?  I'm only using Noctua because it requires such a small amount, and is non-conductive.

I start with a small ball of it right in the middle, and with a latex gloved finger circle it out to the perimeter in non-stop motion.  The ball is about 3.5 mm in diameter, and a good way to put it is that the amount is enough that you just can't see through it, but close.  This is done before placing the processor....

On your other post you got some advice.  Step back a bit.... check the boot block date in your BIOS.  What processors you can use are quite different if you have the old boot block date versus the newer one.  That is all in here.

For the Z600 going up to 130W processors is quite expensive..... they need a rare and expensive heatsink/fan.  One socket can use your Z400 original, but the other will be hard to find.  I've posted all about that here.

EDIT:  THE Z400 PERFORMANCE HEATSINK HAS HEAT TUBE TIPS THAT PROJECT UPWARDS ENOUGH TO KEEP THE SIDE LID OF A Z600 FROM FULLY CLOSING IN MANY CASES.  IT DOES NOT SEEM WORTH THE TROUBLE TO FIND A WORKAROUND TO THIS ISSUE.  RATHER, SEARCH OUT THE OFFICIAL Z600/Z800 PERFORMANCE HEATSINK/FAN WHICH DO NOT HAVE THIS PROBLEM.

Good luck.... get a tiny pick, a good light and take your time.  You might end up with a Z600 running on 1 processor only, in socket 0.  Check your boot block date, and then get the fastest 95W hexacore approved by HP for your version if that ends up being the case.

[Sketchup]

I used Artic MX-4 it's no conductive and I've read successful attempts removing it without too much difficulty.
I am waiting for a sunny day to make my attempt (it's snowing)

my BIOS are the C2 rev and I got a x5660 now, the best version is the x5675 (if I'm not mistaken) but that was not worth the price difference from my choice. I'm starting to get familiar with the z series hardware!

if I lose the socket than after I finish cry, I will have to shop for another... hopefully not the case!

[Sketchup]

update, problem still exists but it was not the thermal paste, on very close inspection there was no contact with the pins and after very thoroughly removing any the same no boot/BOIS persisted. I'm currently running on only socket 0.

I will continue with testing the CPU in the other socket if that boots than I know there was a motherboard issue.

thanks for helping!

[SDH]

Please keep us posted, and good luck on the project.  I don't get how there could be no contact on the pins.... it is purely mechanical at that level.

All your options are open with that later motherboard.... you can use the older and the newer approved processors.

I'm thinking it will be the second processor being bad, and that you'll be able to send it back or just contact the vendor and get a good replacement.  For others.... there are some great deals on used processors from eBay vendors from Hong Kong/China (same thing for this purpose).  However, for processors I only buy eBay used from USA vendors with very good ratings.  Over the years I've only had 2-3 bad processors out of over 100 (getting close to 150, probably) and always have got a functional replacement from a good vendor (usually on the honors system, with no request to send back the original).