Troubleshooting PCG-GRT240G CPU replacement

rsvenkat14

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Sep 22, 2012
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Hi there,
I acknowledge that I ventured something that typically no one recommends for a laptop. But if you have any suggestions, I appreciate that.
I had an 8 year old Sony VAIO PCG GRT240G laptop that I tried to change the CPU. The laptop comes with Intel Pentium 4, 2.67Ghz, 512KB L2 Cache, Code Name Northwood processor. I read the compatibility factors and tried replacing the processor with Intel Pentium 4, 3.4Ghz, 512KB L2 Cache, Code Name Northwood processor. I took great care opening up the laptop and removing the heat sink and then replacing the CPU. After replacement, when I tried to power on, the two battery light glows solid orange but no other reaction from the computer. Laptop appears to be dead. So I went back and replaced the old processor that came with the computer and also replaced the RAM with originals that came up with the computer. When tried to boot the machine with all the original parts, it still gave the same behavior. No sign of any life other than two orange lights (battery1 and battery2) glowing. Any idea what is going on here?

Regards,
Venkat
 

phyco126

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Nov 6, 2011
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You may have unplugged something and forgotten to plug it back in.
Or perhaps you bent a pin on the processor unknowingly.
Or you shorted the motherboard by not taking proper safety precautions to prevent electric shock from static or from another source.

Did you remove the battery, plug, and then press the power button afterward to ensure the system was drained of all electrical juice before tearing into her like a savage beast?
 

rsvenkat14

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Sep 22, 2012
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Hi Physco126,
Thanks for your response. Apparently a couple of threads on the internet suggested to leave the laptop plugged overnight and try again. Seems like the CMOS Battery needs to be charged. I am not an expert there, but thought of sharing with you an information that worked for me.

So the laptop powered up this morning with no issues with the old 2.67GHZ CPU. Now when I swap the newer 3.4Ghz and power on, the fan turns on, there is power in CD ROM drive that I can push the button for it to open, but nothing else. Blank Screen. Tried pressing F2 to access Bios Menu, but no response. My conclusion at this point may be the motherboard MBX-86 can't handle the 3.4ghz Pentium 4. My guess at this point is that my native CPU was a mobile Pentium processor with 533MHZ where as the 3.4 is a non mobile with 800MHZ system bus. Kicked myself for not doing my homework well. Here is the link for the 3.4ghz processor spec. If in your experience can confirm my understanding, i shall stick my old processor back and throw the newer one on ebay or ewaste.


http://ark.intel.com/products/27504/Intel-Pentium-4-Processor-supporting-HT-Technology-3_40-GHz-512K-Cache-800-MHz-FSB

Regards,
Venkat
 

phyco126

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Problem is, with laptops, they have very limited CPU support. So because a processor fits, doesn't mean it will work (as you are finding out). To ensure you have the best chance of it working, you will have to update the laptop's BIOS to its latest before switching with a new processor. Even then, there is no guarantee that it will work.

What laptop model do you have?
What processor is the original in the laptop?
 

rsvenkat14

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Sep 22, 2012
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Laptop Model is Sony VAIO PCG-GRT240G

Laptop Specs can be found at: http://esupport.sony.com/US/p/model-home.pl?mdl=PCGGRT240G&template_id=1&region_id=1&tab=manuals#/manualsTab

Latest BIOS for this is R0162F0.WFH that can be located at http://esupport.sony.com/US/p/swu-download.pl?mdl=PCGGRT240G&upd_id=1406&os_group_id=13

There is no BIOS menu to change the CPU attributes such as Clock, System Bus Speed or Cache. BIOS menu is pretty rudimentary.

The processor that came with the laptop is Intel Pentium 4 - Code Name: Northwood: Capacity - 2.67 Ghz (yes it is 2.67 and not 2.66) 512KB L2 Cache 533Mhz. By the way, I couldnt find a 2.67Ghz specs at http://Ark.Intel.Com page though. Everything there under Intel Pentium 4 is 2.66 Ghz. But my computer specifically shows the clock as 2.67Ghz and it is way the processor came out of box. I didnt do any over clocking

Motherboard Chipset: SIS 648 - I couldn't find anywhere how it maps to Intel processor chipset list such as Intel 865G or Intel 875p.

Thanks again Phyco126 for your responses. Though it is an old laptop, it is hard for me to go to sleep sometimes without understanding what in the world was wrong with the processor I tried to change :) Guess, I messed up the compatability between motherboard and CPU but dont know the exact reason yet. So I am truely grateful for your time and guidences.

Regards,
Venkat
 

phyco126

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A pentium 4 at 2.8 GHz is the maximum processor you can have in your laptop, according to technical documents.

Your Pentium 4 is actually a 2.66 GHz chip, which is why you can't find any information on it. It may show up as 2.67 GHz in your system for various reasons, the least of which can be because its actually normal for chips to run + or - .05 GHz.