Halp! My Precision M6600 is dead!

I hope someone can help me with this strange problem. My M6600 has an i7-2820QM, 16G RAM, 2 HDs (one Linux, one Windows 8.1), a Quadro 4000M, and Blu-Ray drive.

I was playing a game with the machine docked and the system instantly powered off. I thought it may be heat, given the context, but waiting for it to cool did nothing.

Ever since then, it seems to power up for a fraction of a second, then goes dead. The fans twitch, as well. If I hold down the 'D' key, it powers up and goes through the display panel test, then immediately shuts down again.

Repairs that I have attempted to no avail (I am an experienced IT pro, so complete disassembly/reassembly doesn't intimidate me):

Switched to another battery, known good from another machine
Reset CMOS by pulling CMOS battery and pressing the power button
I thought 'surely it's the mainboard', so I bought a pull off of eBay and replaced it- no joy.
I then thought 'it could only be the processor at this point', so I bought one from eBay and replaced it- nothing. Exactly the same behavior.

I have also tried to power on the system (with both boards & processors in all combinations) without the Quadro 4000M- same.

Without a processor, the boards will blink the 'CPU failure' code.
Switching RAM does nothing, and even without any installed the boards don't detect that- the system always just powers off immediately.

WHAT AM I MISSING??? (frustrated!)

 

Did you try each RAM stick in turn or some other RAM?

John

 

Thanks for the reply- yes, I did try the RAM in pair combinations (I have 4 identical sticks for that machine). Interestingly, it should detect when there's no RAM and blink a code on the power/disk/etc LEDs, but it doesn't do so- just the same behavior of very briefly lighting up then immediately powering down. I have also tried on & off of the dock, and with 2 different power supplies.

The dock and its power supply work fine for a Precision M4800 that I'm borrowing from work until I get this problem sorted.

 

Have you tried the absolute minimum connected to the board? One stick of RAM (preferably not from the dead machine in case the very unlikely happened and they all died at the same time) and no storage drives. That should be enough to get into the BIOS as a start. If not, suspicion must fall on the CPU (which I understand you carried over to the new board).

John

 

I did try with combinations of pairs of RAM modules, and with a different CPU as well (i7-2860QM- still Sandy Bridge, should be compatible). I'll check again tonight with some additional RAM I've borrowed.

 

Nevermind, sorry. I see now that you did already try a different battery. Disregard the following.

I wonder if it could be the battery. I don't remember if the precision are this way, but some laptops if the battery is depleted and dead, the system won't start up. You could try removing the battery and running just off the AC to see if that changes anything. If so then replace the battery.

 

Results of the test with another set of (known good) RAM- negative. Still the same behavior- short blink of the battery light, then immediate power down. What frustrates me most is that ANY of these fixes I have tried could have been the problem, but apparently none of them are...

I just can't understand how after replacing the mainboard and CPU it still won't boot at least to the BIOS stage, configured minimally with or without the discrete video card, minimal RAM installed and no storage connected.

I hesitate to throw anymore money at it, since it's a 3.5 year old machine, but a premium machine should certainly last longer than this...

 

I'll try grasping at straws... could it be related to the power source? ie. the AC adapter or the dock itself or perhaps the docking connectors?

 

Thanks for the reply- grasping at straws is where I'm at as well. The system behaves the same whether or not it's connected to the dock or powered externally through the AC Adapter, or by the internal battery- all are the same (broken). The dock power supply is separate from my AC adapter, and all of those (and the same dock) will power the Precision M4800 I'm borrowing from the office without complaint, so I can't see how it could be the power supplies, dock or battery. Both mainboards also behave the same on the dock. Maybe the CPU is the issue, AND the one I bought is also dead? Doesn't seem too likely, but again, grasping at straws...

 

The only issue I ever had with mine was the video card...
With no memory my m6600 spins both fans, dvd drive, and shuts back off with an error.

Power switch board?