No POST after CPU upgrade

av-115

Reputable
Dec 23, 2015
11
0
4,510
Hello,

I'm having problems upgrading the CPU on two separate machines so apologies for posting in the same thread.

First machine is a Dell Dimension 4600. Upgraded from a 2.8Ghz Pentium 4 533Mhz FSB 512Kb L2 Cache to a 3.4Ghz Pentium 4 HT 800Mhz FSB 512Kb L2 Cache. System does not POST with new CPU in it. Fans and drives spin but power light is amber and no display at all. System works fine when old CPU is put back in. New processor is stated as being compatible in service manual: http://downloads.dell.com/Manuals/all-products/esuprt_desktop/esuprt_dimension_desktops/dimension-4600_service%20manual_en-us.pdf

Also posted about this computer on the Dell forums and someone said the CPU was compatible with Dell motherboard P/N F4491. Mine says CN-0F4491 but could this be the same thing? Here's the thread: http://en.community.dell.com/support-forums/desktop/f/3514/p/19665314/20858052

Second machine is a much more modern Lenovo IdeaPad Z500 laptop. Tried to upgrade the Intel i5 3210M 2.5Ghz to an i5 3360M 2.8Ghz. System does not POST with new CPU. Again, works fine when old CPU is put back in. 3360M is listed in parts list of hardware maintenance manual: https://download.lenovo.com/consumer/mobiles_pub/ideapad_z500p500_hmm_1st_edition_sep_2012_english.pdf

Both machines have latest BIOS installed. Both CPUs were bought on Ebay (different sellers). The Pentium 4 was £10 and the i5 was £30. Could the CPUs be faulty? Are they in fact incompatible or am I missing something? Hope someone can help. Sorry for the long post!!

Thanks
Andrew
 

av-115

Reputable
Dec 23, 2015
11
0
4,510

Thanks but don't have new RAM to try. Tried with just one stick, makes no difference. Everything works fine with old CPU in. Did find a bent pin and a missing pin on the P4 though so can only assume that's what causing that not to work. Still not sure about the i5.

Merry Christmas!
Andrew
 
G

Guest

Guest


Merry christmas to you too!

 

av-115

Reputable
Dec 23, 2015
11
0
4,510
Sorry to bump an old thread (I hate doing this). For anyone else with same issue, the P4 3.4GHz wouldn't POST because it was damaged. There was a pin missing, barely visible without using a magnifying glass. Returned for a replacement and it worked straight away. If your 4600's m/b has part number 0f4491 like this a 3.4GHz Pentium 4 WILL work with BIOS A12.

Never got the i5-3360M to work in the Z500, no idea what was wrong with that.