Computer won't start. PSU good. Amber light on mobo. What gives?

optiplex comes in 3 or 4 case types, and matching different mobos.
gee golly. which is it?
i hear nothing,?
if you want to guess, just do so your self , your cash that%$$

want to do testing first, say so, diagnosis? guessing is your job.
if that is what you want to do. ?
testing.

• first off, you push the power button and the 2 fans spin do they?
• unstated by you this super key #1 fact.
• the manual states powerlamp flash amber why did you not say which lamp LED flashes? page 73 in your manual.
• the 4 diagnostic LED? or ? what? page 99 powerled blinks
• Blinking ambe POWER LED light indicates a
  problem with the system board.
• so there you have it main board issues, when you see that it means to strip the system down to minimum system to find shorted devices, all PCs do this, all things in a PC can in fact short at any time. (fate?) so we just unplug devices, DVD drive all HDD, all SSD,
• then unplug the video card in th PCI slot, or any card in any PCI slot of any kind, does the blinking amber end and fans run now the PSU fan must run the CPU fan must blow. do they?
• The ram sticks pulled , and tested 1 by 1, did you do that.
• remove all usb devices just as precaution, most usb ports have there own regulators and do no allow overloading main PSU rails. ever, but we unplug all we can, see?
• did you bench test the PSU first>? both? using the magic jumper check. see at link below.

here is PSU checks
http://www.pcdied.com/power.html#rapid_testing

in our shop we have load bank tester for all PSU.
that burn power, and fully load PSU, but most times we dont need it.(we also have noise checks for PSU, tools)


here is mobo bad checks.
ive no idea of this PC is factory stock or not?
some folks mix parts, put dell mobo in to alien case?
but here is all ways to mess up mother boards.

http://pcdied.com/intel-magic/m.2/update-mobo.html


things not told by you.?

1. is it still like dell made it new?
2. are both fans dead, amazing I have to ask but are they? the fans must turn fast and actually blow air both,
3. do you have things in PCI slots.?
4. what wattage rating is the PSU? 200w? or 500w?
5. ram tests (pulls and swaps)
6. PSU bench testing? did you? with the jumper, and see fan spins and all rails to to spec voltage with any $20 dmm meter made.

did you do a coin cell reset.
remove all wires to MOBO, cept power button tiny wire conn.
remove COIN cell
push power button, this discharges all caps now.
and NVram is now erased,
now put mobo back online, power and all, and see thaT FANS RUN
AND BIOS SCREENS POP AND IF DO , select BIOS defaults now.

your RTC coin cell is 7 years old today, and is the end of life point.
so says the battery maker, consider a new one?
or measure it with DMM, 2.9v and less is bad or at the deathh knee of life. 3.3v is new voltage.

YOU HAVE PROBERLY A BAD PSU.TRY WITH A OTHER PSU IF POSSIBLE.

The Dell Dimension 300 gets the amber blinking light when there is power to the computer (the power supply) but the motherboard isn't getting the correct power. Sometimes it can indicate a motherboard fault or that the power supply is not set to the correct incoming voltage.

Check the back of the computer. If the power supply has a switch for incoming voltage, make sure that it matches your incoming voltage. Next check that the main power cable (20 or 24 pins depending on the computer) is fully seated on the motherboard. (It can only be connected one way and should lock onto the connector on the motherboard.)

Next check that the power supply is providing the correct power. You can simply install another power supply (known to work on another computer). Make sure that the PSU is correctly sized for the computer components. Alternatively use a multimeter or a dedicated power supply tester or put it in a different machine.

If the problem is not cured with a new PSU, the motherboard has a failure. Unfortunately, it's difficult to identify the exact bad component. (If a major component other than the CPU on the motherboard had failed, the diagnostic lights or beep codes could help identify the issue.)

I hope this helps.

Cindy Wells

LOL... If you haven't already fried your motherboard by using your modified PSU (And that's a big IF), then you need to buy a new PSU with similar specs and connection plugs (ie. a 24pin main) as the original PSU that came with the PC.

Many flavors of this video card from various manufacturers have different configurations - most important is the auxiliary power connector that appears on the edge of many of these cards. If your ATI has such a connector, it must be connected to the PSU. The MoBo bus can not supply the required power via traces on the board. If connected and it doesn't work - it may be a power supply problem.

While your 500 Watt power supply unit (PSU) is more than the 400 Watt minimum requirement, but depending on its efficiency and your system configuration, may still be on the "weak" side. Your particular PSU is not a certified type. ATI recommends using certified PSU's on this list. You could probably get away without using one of those expensive PSU if you got one with a little more "umpph" to it, say a 600 watt or more rated type. The 500 watts unit you currently have may be "just a little too close" with your PC's configuration.

I hope this helps & good luck!

First remove the power plug from the smps and press the power switch few time and wait for few minutes the re plug the power connector to the smps and switch on the computer if you still dont have power then you will have to check whether the smps work to test that its not enough to test the voltage in the 21/24 pin you will have to short the green wire and the black wire and see whether the smps fan is working if the fan is not working then the problem is with smps

check ur PSu (smps) or ur mobo ic is get damaged u need to service it

then your psu might be bad.

Most DELL's I have seen with this condition it was either the motherboard or Power supply. If your mobo looks fine (see explanation below) then I would try another power supply first. Use one that has the same or greater output watts. I keep several old ones around for this purpose. If that does not solve it then you may have a failed motherboard. Failure of motherboards is usually due to breaking capacitors. A few years ago a capacitor company stole the "recipe" for making capacitors from another company and tried to make their own, unfortunately they did not get the ingredients right and the capacitors started breaking after 2-3 years of use. They sold these capacitors at very cheap prices and a lot of computer companies and power supply makers bought them. This is easy to diagnose. Look for capacitors (caps) (they look like little tiny soda cans) on your motherboard (mobo). They should be perfectly flat on top and not bulged or swelling or leaking anything. Be sure to look under the fan shroud also. The dead giveaway will be the fact that you are not getting anything after you change the PSU. There are a few companies that will repair broken capacitor issues. Also if you add a bunch of extra components without upgrading the power supply you can suffer underpowered situations and that can cause internal parts to fail. To eliminate some other stuff you could remove the memory and disconnect all the power plugs from the drives and then try to start it up. If it does not change the behavior at all (no beeps, no change in flashing lights) then you probably have motherboard issues. Make sure when disconnecting the memory chips (sticks) that you touch the metal on the inside of the case first to discharge static electricity. If it does change the behavior add 1 component or item back at a time to see what you can find out. Post back with what you find. And remember a bad PSU does not always mean no power, just not enough to run the computer. I disagree with the post by GUEST. If you are having Hard drive issues the amber light will not sit and blink at you. I don't know how many DELL's they have worked on, but most DELL's I fixed had 1 of those 2 problems. If mobo looks good then try a bigger (more output watts) power supply. If you have the 4 tiny A-B-C-D Diagnostic lights on the back, what state are they in (amber/green/off)? This may help us diagnose further.

I have this type of computer (just sitting around , not for my main computer) and I had a smilar problem. I took it to a guy I know (who owns a computer repiar shop) an he said the motherboards on this model go haywire about four years after initial power-up. On mine, it caused the power supply to blow-up (literally) and blew out most components. (Floppy drive, Sound card, USB ports, Keyboar/mouse plugs)

I really don't know if What he said is true, but I replaced the power supply, and now it works fine.