Fans in my Inspiron 546 are racing

Always include version of Windows in your posts. :Idea:

Did you clean the surfaces and apply a thin, even coat of thermal paste (eg, Arctic Silver) to both the heat sink and CPU when you moved the hardware over to the new motherboard?

Sure the motherboard battery is any good? Did you remove the battery and press/hold the power button for ~30 sec, before reinstalling the battery, after you installed all the hardware on the new motherboard? Otherwise BIOS might not correctly recognize all the hardware that you installed.

Do you have an add-in video card or are you using onboard video? A racing fan sometimes means there's a video card problem. So possibly an add-in video card died or maybe you have a corrupted video card driver.

If you're using an add-in video card, physically remove the card from the PC and connect the monitor to one of the onboard video ports (VGA or HDMI). If that works, then the card may have died.

If onboard video works and then you reinstall the card, what happens if you boot in Safe Mode? If that works,  you may have a corrupted video driver.

And if none of that works, strip it down to bare essentials. Disconnect all drives except the boot hard drive, remove all add-in cards, except video (after doing above testing), remove all RAM except the module in slot 1, do the battery thing and see if it will boot now...

Another PS,.  Just in case you are not aware:  The initial problem of not booting included the study yellow/amber light on the front of the computer rather than the silver white normally,.

Thank you for your reply,  I did clean both the cpu and heat sink and applied new conductive paste,

The motherboard is a refurbished unit from Dell which I just installed, I assume then that the battery is new, but i did the test you described anyhow, 

Since you bought up the video; Before my computer shut down and was working ok, when I turned my compeer on, a series of horizontal colored lines would appear at the top of my monitor screen & then go away and the computer would boot OK and would operate Ok from there on. Now, what I get on the screen is a mottled greenish screen with a bulky blue border all murky,

In doing research & googling a lot, I saw an article describing things that a bad cpu could cause and month them was racing fans. So, I made a choice to buy a twin pack of 2 used cpus and tried both of them but the results were the same,. 

It appears that I replaced everything hat can be except the video unit.

PS. Sorry, I must add; O/S is Windows 10 after Windows 7

You still didn't say if you're using an add-in video card or onboard Intel Graphics.

Those strange patterns on the monitor suggest a video card issue. So if you haven't already done it, pull the add-in video card and switch over to onboard video.

And can you test this monitor on a different PC or a different monitor on this PC?  In either case, use the same video port on the monitor that you use with the 546.

I'm assuming that when you say on board, it's part of the motherboard & if that is so, wouldn't a refurbished motherboard include a good on board video card, I am sitting here with the computer  opened on my work table & can see everything inside & I don't see anything that can be construed as being the video card., 

Lets back up. This is an Inspiron 546, not a 546s, correct? I assume it's a 546 in the following:

What color is the power button, and is it steady or blinking when PC won't boot? 

• If the power light is blinking amber - The computer is receiving electrical power, but a device might be malfunctioning or incorrectly installed. You may also have to remove and then reinstall the memory modules.

Onboard video is built into the motherboard, so you won't see a "card". A replacement motherboard would only come with onboard video (presumably that actually works), but not with an add-in video card.

You would have had to move an add-in video card (either AMD or NVidia) from the old motherboard to the new one. Did you do that?

The add-in video card would be installed in the PCI-e x16 slot on the motherboard. See the motherboard layout on page 45 of the service manual for location of that slot.  (Make sure you look at the 546 diagram because the Inspiron 535, 537, and 545 are also included in the same service manual.)

Look at diagram on the page numbered 16 in the setup guide. This PC has both onboard VGA and HDMI ports. The VGA port is blue and the HDMI port is directly above it, both in the area marked "4". If you have an add-in video card, it would be in the area marked "5" in that diagram.

What video port are you using, either onboard or add-in, and is it VGA, HDMI, or other, since an add-in card might also have additional ports. If you have an add-in video card, the 2 onboard video ports would be disabled so the monitor must be connected to the add-in card.

Have you checked this monitor and cable on another PC or tried a different monitor and cable on this PC?

Thanks for your reply Ron. My unit is an inspiron 546. If there is any controversy about the model #, it is in the fact that my paperwork when I bought it refers to it as a 546MT. On he back of my computer it says it's a 546. 

The power light is on steady Amber/Yellow when I plug it in,

The part number on the replacement mother board is exactly the same as the one in my computer. I checked it component to component and the only difference that I saw was a slight variation in battery case tabs that hold the battery in,

The only "cards' in the unit are the memory cards which I removed with the exception of #1 . I have a total of three which I removed from the old motherboard. After installing the replacement motherboard, I started the unit up with no change so, I did put one memory board (#1) back in to see if made any difference when I started the computer back up again but it didn't.  

Going back, I remember after installing the replacement motherboard and starting the unit up there was no change, the amber/yellow light was on steady the fans ran at regular speed, the green light was on to the power supply and the light was on by the battery, Physically that's about all you see operational. Then I opted to check the power supply again and I disconnected everything that it was connected to and there are four groups of cables coming from it. Two of those sets of cables terminate at the motherboard, the 24 pin and a four pin, of the other two, one goes to the hard drive and the other to the CD drive. The power supply checked out good again and I reconnected everything and turned the computer on and that is when the fans went racing and that's the way it is now.  So, at this point, I'm thinking that something happened to the power supply so I took it out of the unit to check it again,. I plugged the unit in and the green light to the power supply goes on and as soon as I insert the jumper (modified paperclip) to green & black, the  fan comes on and the green light goes out. Then I check all he voltages and they check good. The question that comes out of that is should the green light go out and if not is something shorting out in power supply or is the light supposed to go out when the jumper is inserted?    

Note: When the problem on my computer developed. (Won't boot) and there was nothing that I could source or try that would get me into the computer: So, I thought right off I would buy he least expensive item (power supply) & I ordered it as a 546MT which is what my paperwork states and it turned out to be wrong because there are more cables coming from it that what is in my computer. It came damaged anyhow and opted to send it back but they just refunded and I still have it. 

You're still using the original power supply.  Correct?

Is the new one a Dell OEM PSU or something else? Even if the new PSU has more cables coming out of it, that doesn't mean it wouldn't work with the 546.  Assuming it's a Dell PSU, it's possible they started using a different version with more power outputs, but Google its (Dell) part number to see if there's any links to the Inspiron 546. BTW: How was it damaged?

Read this and this to troubleshoot the power supply. The green light should probably not go off when you jumpered it. Does it go off when the PSU is fully connected to the motherboard and you power on? If it goes out, then suspect the PSU, even if the voltages seem to be ok. The PSU may be failing when it's under load.

Unless you're very unlucky, since you had the same problem with the old motherboard and old CPU, they're probably not at fault.  Assuming it's not the PSU, disconnect all drives from the PSU and remove all 4 RAM modules from the motherboard. Do you get 2 beeps (= No RAM detected) from the tower when you power on? If not, you may have a bad motherboard.

And only you can decide how much time/effort/money to put into this older system...

Yes, still using the original power supply and the new one I spoke of is a generic and there are a couple of connectors that aren't included that would connect to the motherboard,.The damage on the unit was external but suggested a heavy hit which may or may not have caused internal damage,. I accessed both "go here" sites and from what i see, there aren't anything that I didn't do. I am thinking that although the power supply might check out good with the simple test, that there might be a problem under load. I am going to reinstall the old board with the intention of going back to the state where my computer failed, just to get another start.  I am thinking I jumped the gun going right for a motherboard replacement. 

I just want to run this by you; If i happened to hit the sleep button in error, could my computer still be in that mode? I do not have the key on my keyboard that would give me the option of waking it up. So, if it is asleep, how could i wake it up without that  key.?

Presumably your PC would wake from sleep just by moving the mouse or pressing any key on the keyboard. And if you rebooted, it wouldn't still be sleeping (solid amber power button).

Yes, get a new power supply and try that. But do you really want to go through all the trouble to revert to the original motherboard at this point? Just plug in a new PSU and see if that works. If that does it, you could assume the old board works and either keep in as a spare or sell it.

Let us know what happens when you replace the PSU.

No matter what, I am going to get a new power supply and yes, I will let you know what happens. Meanwhile, I did some inquiring about the power supply which I believe is of the switching variety. As I described earlier what I experienced when we had power failures in our house whereby the computer doesn't go off all together but assumes a high speed fan mode. Accordingly, shutting the power down to the computer completely and then turning it back on will trigger the switching mode in the power supply to turn the computer back on. 

You know, usually when it is necessary to shut a computer down without going through the usual process, you would push the power button in until the computer shuts down. When I plug my computer in at the power supply, it starts the fans up running at high speed and I cannot shut it down by holding that button in, I have to unplug it from the power supply. Would that offer any kind of clue to what the problem is?

sdown but that doesn't work when my computer goes i

Don't know if those symptoms help solve the mystery, but it sure sounds like you're in serious need of a good surge protector and an uninterruptable power supply to protect your hardware from all these power blips.

BTW: You might contact your electric company and tell them their blips have damaged your PC. Some of them have insurance to cover such damage. They may make you jump through a few hoops, eg provide dates/times of the blip(s) etc, but if you can even get close to when they happened, they might cover the cost of a new motherboard and/or power supply. :Wink:

Started out a couple of weeks ago yellows/amber light on steady. After numerous discussions; replaced, motherboard (Dell refurbished), power supply & CPU. Still have steady yellow/amber light. Had a speeding fan issue along the watt but new power supply solved that. Out of options. Help.