Bad Mobo or CPU?

[ck1402]

I am torn a bit on this one. I get a laptop in that is consistently freezing up on my client. It froze on be for a second so i tear it apart and find there is a ton of dust between the fan and heat sink on it. I clear out the dust get it booting up again and fun a chkdsk and sfc scannow. I did a hard drive test as well. i had this thing running great for 5hrs straight. He takes it home and it freezes up again.

Brings it back this morning i boot it up and it starts to work fine then freezes on me. The image on the screen is still there however red lines are ghostsed behind it in the middle of the screen and the CPU indicator light is not active.

So i boot it into the bios screen... same thing happens.
Its an
Acer Extensa 5420-5687
AMD Turion 64 x2
I bumped it up to 4 gigs of ram.
I also recently replaced the touch pad and mouse buttons on it.

When i pulled the processor out of it the thermal past looked pretty rough.
I am going to clean the and reapply fresh thermal grease and see what happens. I am just not sure if it's far to gone already.

 

[NYJimbo]

What temps were you getting before and after the clean ?

 

[ck1402]

No idea to be honest. Before I could do any temp test it freezes up.

 

[ComputerRepairTech]

whats a cpu indicator light?

You said you bumped it up to 4gb, does that mean that one stick of ram that was in there originally is there there? if so did you do a memtest?

 

[ck1402]

I ran a memtest on it. It has 2x2gb running in it. I just cleaned the CPU reseated it with fresh thermal paste. The problem is still there. I think it's the video chip. If that's the case the mobo is shot. I went into the bios to get temps and it was worthless there was no diagnostic info at all. So I am running full hardware tests on it again starting with the harddrive and going thorn there again.

 

[Boston Pro Comp Serv LLC]

CPUs almost never fail, I can count on one hand the number of bad ones I've come across in a lifetime. I think I've only seen two that failed on thier own the rest the user burnt out themselves.

 

[ck1402]

That's what I was thinking. CPU passed. Running them memtests now.

 

[NYJimbo]

No idea to be honest. Before I could do any temp test it freezes up.

I mean what temps did you get when it was working ? You really should check the temps after cleaning a fan so you know everything was okay and you don't give the customer a machine that is going to kill itself from overheating.

 

[LifelineIT]

To me the red lines on the display scream video crash. Not sure of the internals on that specific machine, but it may have a heat pipe and/or sink for the chip.

Probably cheaper to replace the MoBo w/ integrated chip than it is to spend ages troubleshooting and reflowing/etc. Just buy a dummy board and move the guts over, should be pretty straightforward.

 

[ck1402]

Currently the temps are between 52-5C
This is after I reapplied fresh thermal paste today. However even after this it still froze on me with the red lines. The heat sink on it is the bar type that also covers the gpu. Doing a sector test on the far drive right now.

So far running HDD scan and open hardware monitor in windows the CPU usage is at 100% the temps are 60.0

 

[NETWizz]

Unless the laptop has a separate video card like the old D800 Latitude and 8600 Inspiron, you almost certainly need a motherboard. The dead give-away is the lines on the screen AND that it freezes sold (mouse pointer, too)... this screams you have a hardware problem.

If you always see these red lines, it could be a bad LCD in which case I would test it with an external monitor. Otherwise, you can be certain it is a bad video card, which is integrated with the motherboard that needs to be replaced.

****

1. CPUs generally do NOT go bad (i.e. Probably fewer than 1 in 2000) nor does the thermal interface material between them. Sometimes people put it on to thick or they use a stupid thermal pad and the temps are too high, but that is only in select models... When this happens it isn't going to freeze freeze freeze one day and be fine for 5 hours another day.

I doubt your problem is thermal. Thermal problems are usually due to cat and dog hair plugging up the heat-sink fins & fan... or a fan that simply goes bad. When this happens, you clean the debris then replace the fan (if needed). If after cleaning/replacing heat sink and fans, you still get erratic temperatures or the motherboard is otherwise ****** off at the temp it is running, you would be stuck replacing the board.

The hard drive you tested to be good even though I would NOT suspect it given the symptoms you indicated. A bad HDD would generally NOT cause a hard lock up. Bad hard drives usually cause certain files not to open, extreme delays opening applications, systems that fail to boot complaining about "HDD0 Not Found (or similar), NTLDR Missing, WINDOWS\System32\SOFTWARE registry hive missing or corrupt..., BSOD of INACCESSIBLE_BOOT_VOLUME... that sort of thing." When in Windows you might get a prompt saying something silly like "not enough free space to delete file" or "Volume C: Needs to be formatted"

Hard lock-ups (mouse pointer frozen) scream hardware difficulty with something like the motherboard, RAM, video card, a PCI card, etc.

**********************************


1. Verify the RAM isn't bad

2. Remove the wireless (and any other card i.e.. Bluetooth) then try again.

3. Remove the coin-cell battery and add it back (some laptops have this), reset the BIOS to default, flash the BIOS... Whatever


After wasting a half-hour of your life doing all of the above, you can probably be 99% sure you need a new motherboard (vs. the 95% certainty you had before)

 

[ck1402]

Thanks for everyone input. Definitely has given me somethings to think about and to implement in my troubleshooting.

I found its a motherboard issue. It's definitely temperamental. Seems to be behaving right now. I have restarted it several times. Windows updates and what not. Harddrive came back fine. Memtests came back fine. CPU came back fine. Not sure if it's just putting on a show right now or not. Damn gremlins...

Anyways as always thank you.

 

[PcTestCard.com]

Have you checked the RAM as well?

Discharge the laptop by removing all power sources and pressing the power button over 15 seconds.

The previous overheated may have caused some damaged to both mobo and CPU.

Hope this helps.
Bill
Tech Manager, WPTinc.

 

[PcTek9]

I once had a strange problem where the ram would test great, and the pc would run like this... but then when i removed a stick it tested fine again, so i swapped that stick with the other, and presto... errors... the memory diag software apparently could only detect that the ram was bad if only one stick was in the system, if both were in it, then everything seemed fine. just a thing that happened.
I think you are right it's a bad motherboard... You should get one of those tiny portable temp meters. The micro laser instant temp things and keep it on your bench and one in your bag. Great for quick temping stuff... I also have a cooper instruments temperature meter that has: long probes, cell battery shaped probes, and even a humidity meter. Probably if you knew the temps, you would be shocked... I've seen extremely high temps due to dirt encrusted chips... Anyway. good luck.

 

[PcTestCard.com]

CPUs almost never fail, I can count on one hand the number of bad ones I've come across in a lifetime. I think I've only seen two that failed on thier own the rest the user burnt out themselves.

I agreed, seems to me mobo is more likely faulty than the CPU.
Mobo Bios comes with the CPU protection to shut down the computer if the CPU is overheated.

I would suggest we check the mobo.

Hope this helps.
Bill
Tech Manager, WPTinc.