Motherboard & CPU upgrade woes

Z

ZenStalinist

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Okay, So I've been trying to upgrade my Brother's PC, but to little avail. I fitted the new motherboard, processor, and RAM according to instructions, but when I switch it on, the standby light comes on as usual, and all the fans go 'round, including the one for the AGP card, but it doesn't beep, there's no display, and I can't do anything with the keyboard (num lock, etc. give no response in the LEDs.). What part is at fault here? What should be done? I assume one of the parts is fault, I've tried a lot, but the motherboard and the CPU came from different vendors, so I need to know which part is at fault rather than saying 'Something you gave me doesn't work!'
 
The fact that the LED's aren't working indicate that it's something pretty fundamental. I believe these are initialised by the BIOS and then control is taken over by Windows (or whatever the OS is you're using).

Unfortunately as everything has been changed in one go it's impossible to say which bit is at fault. Sounds as though it's not booting at all which could point towards the CPU.

I think I'd be tempted to go for the brass faced approach send it all back and say
'Something you gave me doesn't work!'
Click to expand...
. They might test the items or they might just replace them. Of course, if it was all replaced and the same thing happens again...... :shock:
 
Here's a couple of basic things to check

1) Check if the CMOS reset jumper on the motherboard is in the correct position.

2) Not sure what you have upgraded from/to, but there was a change to the ATX power supply some time ago to include a new power connector. Does your board require this and does your psu have this output (four pin square connector)

Failing that, provide more details of the from/to situation

Regards

Ig
 
Sounds as though the BIOS isn't functioning, the BIOS is located on the motherboard. This is the initial bootstrap that is responsible for the inital keyboard, display, hard disk access functionality. Why prescisely it isn't working, I don't know.
 
Okay, to clarify a few things, the PSU has been upgraded to a new 450watt one with the four pin 12 volt connector. The LEDs on the case work, the power one lights when switched on, and goes off when the reset button is held down... I assume this is just a difference in the motherboard and is meant to be, as on the old motherboard it didn't do that. The motherboard is a AX45F-4DN. So yes, it could well be the CPU, but I'll leave this in discussion for a while...
 
Do the keyboard lights flash (assuming its a standard keyboard)?
 
I've had this problem if the RAM is not seated correctly. (yes I know it should beep, but if the address bus or data bus is being corrupted by a short, the cpu can't make a successful write to port 61H to make the beep). Lift out the memory and check that none of the tiny wire contacts are out of place, then replace the memory (ensuring the locking tags are in place).

If still no joy, try removing everything from the motherboard (and that includes RAM) except for the speaker and CPU. If you get the expected beeps, now try replacing all the items one at a time to see which causes the problem.

If you didn't get the expected beeps with the strip down just mentioned check the manual for the procedure to return CMOS to factory defaults. (There is usually a jumper for this purpose) then try again.

If you still can't get the beeps check the none of the screwheads that hold down the motherboard, are shorting out to a track. If they all look clear, lift the motherboard and check carefully the where the brass stand offs meet the motherboard. These are sometimes too close to a track and the brass stand off shorts.

If the fans you mention are running off the 12v line, it is always possible that it is a PSU fault. Check particularly the 5V supply to ensure that it is actually 5v (give or take a smidgen).

If all of this fails then it is either a faulty motherboard, faulty CPU, or an incompatibility issue between the two. You could eliminate (or confirm) the CPU by testing in another motherboard.

Good luck.
 
Okay, I maybe shall ask my brother (he knows several gamerS) if anybody else has a P4 system I might get to test the CPU in, or whose CPU I can test in his system. I haven't gone so far as to test without the RAM yet, maybe I shall do that in a while. And no, to the other person, the keyboard lights do not flash.
 
take it apsrt and start again, cpu and fan, does that work, then ram you get the idea.

oh did you read the manual for the mobo first, most dont need pins adjusting for cpu voltage, but some do
 
It sounds to me like a CPU problem. Check that it is seated correctly and that none of the pins are damaged.

As for the M/Board jumpers, your M/Board is of the Jumper-less Design so no need to worry about them.
 
I shall call the Komplett helpline tomorow and ask them a few questions regarding return of the CPU.
 
Well me old Sausage, looks like you've made a right Hash Brown of it, Let's just hope you didn't fry your Chips! :)
Looks like a lockup in the POST , as previously advised check CPU is seated properly no pins bent out of place along with memory etc. after earthing yourself to remove static check with front of index finger whether any of the chips are extremely hot ( dont hold finger there too long )
 
The best thing to try is disassemble the whole lot again, then redo it and inspect the connectors on each part as you do. Note that some bits of a PC (AGP/PCI cards especially) do require more force than you would be happy to put on them.

I have built several PCs and one of them (my own) wouldn't work. So, I tried the dis/reassemble and it worked first time after that.
 
I would also check for leaky capacitors as many motherboard manufacturers including aopen were plagued by capacitor problems causing boot failures.

Even if a capacitor doesn't appear to be leaking this could still be the problem. Also it is worthwhile removing the motherboard and placing it on an insulator (cardboard for example) to test it. Connect just the graphics card at first and switch on the mb by shorting the power switch pins with a screwdriver. If it boots great, then try adding the cpu and ram.

A lot of cheap computer cases have a very poor design and can causing shorting on the underside/ edges of motherboards.

Also imho I wouldn't by aopen motherboards - try asus, abit or gigabyte from www.aria.co.uk they are worth the few extra £
 
How would you know if a capacitor was leaky? This doesn't normally mean that they leak anything visible.
 
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