My Dead DV7-4165DX - It Lives! Nooo it dies...

[Flitterkill]

Unlike many people I've had no problems with HP notebooks in forever.

 

The last gen ran hot but mine was/is a trooper; still have him laying around (was slacking flipping it on eBay)

 

My newer guy has dropped out of warranty (45 days past) and naturally, the law of averages eventually got me. I get it. Tech fails at times. Hurts though; and expensive.

 

So save the fan boy wailing about brands and the like - this here is a good ole' fashioned dis-assembly and potential resurrection.

 

PATIENT:

HP DV7-4165DX notebook. AMD Vision cpu, generic onboard video, 17.3" lcd, 640 HD, 4 gigs RAM, BluRay/DVD combo, etc.

Since it arrived it has sat on the living room table and is used for evening surfing approx 3 to 6 hours a night. Never traveled with it. Never been in contact with liquids of any kind.

 

SYMPTOMS:

Two days ago within about 20 minutes of startup the screen flaked out a touch. Color shifts, checkerboard patterns, etc... 30 seconds later screen goes dark and machine is locked. Hard power reset. Begins to boot, screen flakes out. Flashing error codes indicate graphics error and then later system board error. The longer between boot attempts the further it can get in the boot up sequence. Not more than a few extra seconds at a time.

 

DIAGNOSTIC WORK:

When machine was cold used compressed air to clear out vents and fan. No effect. Reset memory sticks; no effect. Holding various keys down to reset system and bios (two HP methods); both with no effect. Hooked external monitor port to separate display to confirm that it was not an LCD error; display activates as it should but dies out when notebook fails to boot (ie no different than display on notebook LCD). Left alone overnight, about 12 hours since last attempt, boot sequence progresses into initial Win7 boot up graphics with swirly orbs which is the farthest I'd had seen to that point, then same lcd errors and freeze. Subsequent attempts immediately afterwards were back to the 5 to 10 seconds time intervals before freezing.

 

WORKING HYPOTHESES:

Research indicated that sometimes the LCD cable that routes through one of the hinges for the LCD display can become scrunched and therefore inoperative. Would have been an easy and cheap fix ($15) however since the machine does not boot even with an external display it's safe to say that ain't it.

 

Options remaining: Bad memory stick, bad cpu, bad onboard video (Northbridge), bad system board, failing cooling.

 

Haven't tested the memory gone bad. Since I have two sticks I could try booting with one and then the other. Have a strong feeling this ain't it though.

 

Bad CPU? Again possible; doesn't feel right though.

 

Bad onboard video? Strong possibility. Unfortunate if true. Requires system board replacement. Cheapest replacement boards are low $200s shipped. Kinda sorta not worth repairing at that price.

 

Bad system board? See above.

 

Failing cooling? Beyond a failing onboard video chip that seem somewhat reasonable. Explains why I can get some progress on booting up; more when it's stone cold. Is it repairable? Possibly, and pretty much the only thing I can do to attempt recovery.

 

How about some pictures to see how your notebook sausage is made?

 

Underside is the usual remove the hard drive, memory, battery, wifi. Unscrew a few more screws and you can release the keyboard and the surface cover.

 

 

That chiclet keyboard is really thin - nothing to it at all. With the underside of the system board exposed, time to remove a few more ZIF connectors, a power cable and the LCD connect. The service manual reccomended removing the lcd from the chassis as well most likely for safety reasons as the notebook is now very much "tippy" but it is absolutely not necessary to do that to remove the system board. Less work for me please.

 

 

Only two screws secure the system board to the chassis. All the previously removed components secured the board merely by their positioning.

 

 

Single fan attached to a heat pipe is the extent of the cooling. The chassis does have additional passive vents, with fabric filters, in various locations as well. Again, positioning within the notebook housing secures the fan component in place except for locking it down upon the cpu. Three screws and it's off.

 

 

Cpu located right alongside the memory slots. Northbridge (which is also the onboard graphics GPU) immediately to the left of the cpu; Southbridge alongside the battery. Note the extensive pinouts for a dedicated video chip and memory.

 

 

 

The pipe covers both the cpu and Northbridge chips. CPU gets thermal goo; Northbridge gets a pad.

 

 

Southbridge. Is that some thermal distortion there? Visually it looks mirror-fine. Camera artifact? Hmmm....

 

These things use so few watts now and honestly the fan is rarely kicking out air that is barely warm most of the time. I should note that the fan and fins look brand new. No hair, dust, anything at all plugging it up. Spotless. Same for the entire computer as well. Cleanest notebook I've seen beyond fresh out of the box new. Still, that Southbridge chip has me wondering... How about the big kahunas? Let's have a closer look...

 

 

Do ya think they used enough goo? Do ya? Consistency between chewing gum and modelling clay. How about fan-side?

 

 

So what do I think now? Gonna try cleaning up that mess on the cpu and see what happens when it is properly goo-ed up. Later on I can grab some very low profile Xbox Southbridge heatsinks and drop one on my Southbridge. And yes, even though though I'm re-using the pad for the Northbridge for the moment (not the best thing to do) there are folks who have measured out the thickness of copper sheets to replace pads and use goo instead in these situations so you can get better cooling. So...

 

1) Reassemble with cpu properly goo-ed. Test.

 

2) If fail, four reboot tries with single memory stick in each slot (2 sticks, 2 slots) to test if sticks/slots are bad.

 

3) If fail, order Southbridge heatsink and copper shim for Northbridge. Install and test. If the problem is overheating of the Northbridge GPU this is my only hope.

 

4) If fail, weep. Then sell remains on eBay or try to justify $210-ish for a new system board (and hope that is the problem...)

 

Thoughts?

 

-Fk

[stutters]

take it to the genius bar at your nearest apple sto...oh, right. nevermind.

 

but seriously, haven't your strong feelings ruled out everything but a faulty board? if i were of the bourgeois and needed to diagnos my own windows machine, i'd probably grab one of these http://www.ultimatebootcd.com/ and try an assortment of tests to validate your hunches and narrow it down to one likely outcome.

 

in the meantime, weep.

[Preacher]

Don't forget that it could be a power supply issue as well. Also it could be more than one thing. Not to be a downer but I agree with what you assess there, it is most likely a system board issue. Sorry you are having issues.

[Madvillain]

Sounds like a bad MoBo to me... which generally in the laptop world means new computer. Guess it could be the on board video too but like you said they are one in the same. Good luck FK.

[amertrash]

Aye, when I was still doing IT I had a stack of dead DV4/DV6/DV7s with that same issue(tho many were part of the nVidia failure which you get a replacement laptop for now). After testing RAM I'd suggest stripping everything off the board you can, putting the board on a cookiesheet with some same balls of tinfoil to raise it up a bit. Preheat the oven to 375, and cook the board for 8 minutes or until the crust is golden brown . Afterwords I'd typically replace the northbridge "pad" with a pre-1983 penny lapped flat with some 1000 grit wet or dry(or you can buy shims on ebay), and replace the crappy thermal gunk with some Arctic Silver. Won't do you any good if the northbridge/southbridge is dead, but if it got hot enough to crack the BGA solder points it'll reflow solder it, I've had some decent luck in the past doing it both with video cards and laptop motherboards. As for the CPU I've only ever seen a single CPU fail, a P4-Prescott where the L2 cache went bad(likewise the machine would run with L2 disabled, albeit much slower).

[Flitterkill]

Oddly enough I was just coming here to post that that is more or less exactly what I'll be doing. I've got a copper shim for the Northbridge incoming along with some Xbox360 copper heat sinks for the Southbridge. Gonna roll with those first before I do an oven reflow. I'm convinced it is either the North or South that are borked; just hoping they are recoverable.

[Flitterkill]

A couple pics in a bit, I've got some spinach and mozzarella stuffed focaccia to finish making (and beer to drink) but yes:

 

SUCCESS!

 

9 minutes @ 395 degrees.

 

Slow cooldown.

 

Copper heatsink on the Southbridge.

 

Northbridge lapped and shimmed.

 

Typing this on my recovered DV7 now

[Flitterkill]

 

Yes, deserving of a dance!

 

 

Stripped of tape substances and stickers. CPU removed. Battery taken out. Only damage during this whole thing was the battery housing. One end had the slimest bit of plastic to secure the battery down. That broke instantly. Not a big deal. Small bit of tape can do the job. if it needs more, the battery is directly exposed when the back memory/hard drive cover is removed.

 

 

Foil in the corners to keep it raised off the pan.

 

 

Baking. Maybe the slightest smell towards then end. Barely perceptible honestly.

 

 

You can see the copper shims on the Northbridge just to the right of the CPU. The Southbridge at the bottom had an XBOX360 Southbridge copper heatsink placed on it (these are aftermarket to fix 360 Southbridge overheating). The shims are replacing a really crappy cooling pad; its copper and and cooling gunk all the way now. The heat sink for South has a super thin sticky cooling pad; you just place it on and it is maybe a mm or two taller than the bios battery assembly. Fits fine.

[Flitterkill]

 

Maybe 12 hours runtime total since fix and it's back to the video crapping out.

 

I never did smell much of anything in the oven so I wonder if it baked enough.

 

I'm thinking heatgun as the next option. Fixed or otherwise this gets eBayed.