desktop pc boots strangely

[omidnia]

Hi all,

I made changes to my HP m7330n desktop and sometimes I have problem when booting up. Two things happen: 1) PC starts and fans go one full speed but then nothing happens (no display or sound of HDD working) and fans stay on high speed forever unless I disconnect the power or hold the power button for 6-7 secs. 2) THEN after holding the power button to turn it off and starting it again after 6 secs, as soon as I press the power button, it starts to flash blue&orange alternatively.

This is the current list of hardware:
Athlon X2 4200+ (stock)
RAM 2X512MB (stock)
HDD 250 Seagate 7200 (stock)
HP DVD-ROM and HP DVD-RW (stock)
VGA PNY nVidia 128 PCI EXPRESS (added)
Motherboard MS 7184 emachines (added in place of MS 7184 HP - since the vga port was not working properly and also I suspected that mobo was the cause of the problem with booting)
PSU Dynex 400W DX-400WPS (added- replaced Bestec  ATX-300-12Z, I suspected that booting problems were caused by lack of enough power)
TV CARD AND MODEM TAKEN OUT

Sometimes when I get the flashing blue&orange I take everything out and boot with mobo and cpu only and it works (I mean no strange boot problems, but stops since no HDD), and later on, adding other components won't cause a problem.
It is totally random and sometimes PC boots up fine and sometimes I get the flashing lights.
I appreciate your help. This is driving me crazy, it's so strange!!!

Omid

[Karnac]

Can you remember any of the changes you made?  Just hardware, or settings too, etc. How old is the motherboard?

Check and reseat memory modules, check the cpu is completely flush to the MB, check that the back end of the video card doesn't move out of the slot when you screw it down, check all connections.......You were in the the case, so some component may have been dislodged inadvertantly.

Next time this happens go into Control panel>Administrative Tools>Event Viewer>...........Click on System on the right hand side and see if the problem is listed........Check the Applications on the right  hand side as well and look for problems.

Also, try a cold boot ....... Turn the PC completely off with the power supply switch on the back of the PC. Give it a minute or so, then turn on the switch on the back and press the power switch on the front. This will sometimes do the trick.

[omidnia]

I made hardware changes only, and the motherboard is recently bought and installed. Also I checked all installations and everything looks fine. Cold boot does not work!!
At this point I only encounter two errors that i mentioned above, and nothing is displayed on the monitor. My final guess is that something must be wrong with CPU, since MOBO+CPU boot doesn't work now. what do you think?
Anyway, thank you for your help.

Omid

[Archer]

   Seems like Your motherboard is dying

[patio]

Was thermal compound applied when you replaced the MBoard ? ?
Is the Dynex PSU still under warranty ? ?
To see if it is the culprit borrow a known good one of 400W or greater and swap it in there overnight.

[omidnia]

There was thermal compound on both cpu and heatsink when I installed them on the new motherboard.
the PSU is new and I got it around 2 weeks ago from bestbuy.
The motherboard was new so I guess cpu is the problem.

Thanks for helping.

Omid

PS. it's hard to find a socket 939 online since those are pretty old now. I'm wondering if it's worth the money and time!

[omidnia]

   Seems like Your motherboard is dying

Why do you think that is the case?

[patio]

How old is the CPU and did it exhibit any erratic behaviour prior to this ? ?

[Archer]

    Because my server had recently the very same simptoms. It's booted like this for about month or so, and it ended up refusing to boot at all. Well, maybe CPU is the problem, I shell not argue with the guru ... but the new motherboard could spoil as well.

[reddevilggg]

PS. it's hard to find a socket 939 online since those are pretty old now. I'm wondering if it's worth the money and time!

I have recently bought and installed a Athlon x64 Skt 939 on this computer. I bought it from ebay, there are plenty on there. Just be careful of return policies.

[omidnia]

How old is the CPU and did it exhibit any erratic behaviour prior to this ? ?

Around 2.5-3 years. I cannot say if it malfunctioned before or not, since I mostly focused on the mobo when problems started. I believe 3 years is not a very long time for a CPU but what I see at this point suggests that CPU is the problem. Athlon's old CPUs are going for over $70 on eBay, Yikes!!

Omid