Member Avatar for DAS-03590

I have a Dell Dimension 4700 Desktop currently in my possession. 3.2Ghz Pentium 4 Processor, 4GB RAM, ran Win Vistax64 with on built VGA and a high performance graphics card. This computer was used for gaming and I had received it from a family member sine they had purchased a new computer.

The problem with this computer is that when I turn it on, the main fan runs at full speed and doesn't slow down. I also noticed i get nothing on the display in any of the ports on the card (VGA, S-Video, and DVI) nor on the VGA on the motherboard. I was told that there is a switch in the BIOS that you can use to change which display to use for POST but since i can't see anything navigating the BIOS is not going to be a choice. Next is that the computer has Hardware fault indicator lights on the back of it but none will light up to show anything.

I have tried removing the RAM, CD/DVD Drives, Floppy Drive, and HDDs, and all Addition cards inside the computer and still the same result with the fan running full speed constant. I'm leaning towards the motherboard being bad but not sure. Tested the power supply and all seems fine.

Any ideas here...

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Practical, focused diagnostics to try before writing this one off. Since later reports the CMOS jumper reset had no effect, the board is failing to initialize—but several targeted checks can confirm whether the motherboard is truly dead or if a replaceable component or setup issue is the culprit. Tie these to ’s idea of cross-testing parts and to ’s note about OEM activation when a board swap is done.

  • Safety/inspect: unplug power, discharge static, remove the cover. Look closely for bulging/leaking capacitors, burn marks, or cracked solder near the CPU/VRM area. A gentle smell check can reveal burnt components.
  • Minimal bench test (outside the chassis): connect only PSU, CPU+cooler, one known-good RAM stick (try each slot), onboard video (remove discrete card) or a known-good GPU, and an internal speaker. Leave drives/cards unplugged. Use a screwdriver to momentarily short the power-switch pins if the front panel wiring is suspected. Listen for beep codes or watch any POST LEDs.
  • PSU verification: either swap in a confirmed-good PSU or measure rails under load. Confirm +3.3V, +5V and +12V plus +5VSB are present and that PS-ON (green lead) and PWR_OK respond when powering up. A working PSU with no POST points to motherboard failure.
  • CPU and fan notes: a fan stuck at 100% is common when BIOS/EC doesn’t initialize fan control. Check that the CPU fan header is correct, and inspect CPU socket pins or pads for damage before re-seating the CPU.
  • Diagnostics tools: a POST/PCI debug card or a simple system speaker will narrow the failure stage; lack of codes with good voltages usually means board-level fault.

If these steps still give no POST, salvage the case/PSU/drives and replace the board with one matching the CPU socket and memory type (OEM Windows may require reactivation or reinstallation as warned). Replacing bad caps can sometimes revive an older board but requires soldering skill.

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Member Avatar for topbarhive

I have a Dell Dimension 4700 Desktop currently in my possession. 3.2Ghz Pentium 4 Processor, 4GB RAM, ran Win Vistax64 with on built VGA and a high performance graphics card. This computer was used for gaming and I had received it from a family member sine they had purchased a new computer.

The problem with this computer is that when I turn it on, the main fan runs at full speed and doesn't slow down. I also noticed i get nothing on the display in any of the ports on the card (VGA, S-Video, and DVI) nor on the VGA on the motherboard. I was told that there is a switch in the BIOS that you can use to change which display to use for POST but since i can't see anything navigating the BIOS is not going to be a choice. Next is that the computer has Hardware fault indicator lights on the back of it but none will light up to show anything.

I have tried removing the RAM, CD/DVD Drives, Floppy Drive, and HDDs, and all Addition cards inside the computer and still the same result with the fan running full speed constant. I'm leaning towards the motherboard being bad but not sure. Tested the power supply and all seems fine.

Any ideas here...

Well, then...
I'm going to figure:
You've cleared the BIOS (jumper on the mobo).
Have reseated all the RAM sticks.
Made sure the CPU-fan is plugged into the "CPU-fan" connector on the mobo.

OK, since the motherboard seems to be at fault, I would try all these removed parts (including the video card) in another system, IF they all work, try removing the ram (testing in another machine --IF you have one available--) and the CPU should be tested in this "available" machine.

IF all parts work, in other machines, it should be the motherboard.

Also, you could just purchase a newer mobo, CPU, memory, etc and reuse the rest of the parts, to have a "better" machine.

Let us know what was the cause.

Topbarhive

Member Avatar for DAS-03590

I haven't tried to rest the BIOS by the jumper yet but i will give that a shot tonight but i have no good prayers for the machine to work even after that attempt.

Member Avatar for DAS-03590

Sorry about not getting back after a while but i feel the board is actually shot since resetting the BIOS with the preset Jumper was not able to correct the issue.

Member Avatar for rubberman

SNAFU, FUBAR, toast. Enjoy your new doorstop! Actually, the Dell Dimensions have good cases, enclosures, power supplies, etc. You should be able to drop in a new mobo, but if you do that, the OEM version of Windows that was on the machine (unless you installed a new one that you bought from MS), will not work, since they check the BIOS and (possibly) CPU information to determine if you are running on the original manufacturer's equipment. If that is your situation, may I encourage you to take this opportunity to not only get a new computer, but also try out Linux? I use Linux exclusively in my consulting business and it works great for me! As someone once said, it is cheap at twice the price, and 10x more secure than Windows!

Member Avatar for DAS-03590

I for one, don't care for Linux, though i have used it and deal with it at work, I mainly have Windows PCs in my possession and as of having an issue with swapping the mother board, i can get one far cheaper than a new computer at the average market and it would be a bit more powerful than your everyday use PC. Also I have had very few if any security problems with Windows since the computer that this was never hit the internet but was used as a file server inside a neighborhood network where it's shared among three houses of the family. Nothing corporate involved so the only things that I have to really do now is get the 'New' computer working again and just recreate the links and all is then fine. Also the Install on the the motherboard with the original key went fine. See no issue with it since it working and passes the Genuine Tests.

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