Cleaned Computer now no power

I just dusted out my computer, and now when I plug in the power cord, the light on the back comes on for a second, then I hit power and the fans go on for like 2 seconds and then stops.

What happened??

Any suggestions?

Thanks in advance.

 

tried all of that already. Spoke with Dell, they are going to replace the system board and power supply.

 

Wow! Did you tell them this happened right after cleaning? I am impressed Dell is stepping up for this, but that is certainly good.

But I would add, don't let this event dissuade you from cleaning out your computers. Everyone should inspect the interiors monthly, and clean when there is visible buildup, especially on the heat sink fins.

Assuming your computer was working fine before you decided to clean it out, if the problem was not caused by a loose connection, I would suspect ESD damage when cleaning. ESD (electro-static discharge) or a static shock from your fingers can easily destroy sensitive devices such as the CPU and RAM modules. Destructive static discharges can be so small that humans are not even aware a static discharge occurred!

Unplugging from the wall is essential, but we must also remember to touch bare metal of the case to discharge any static in our bodies BEFORE reaching in, and often (preferably constantly) while inside.

 

Leaving power cords connected for grounding (earthing) during maintenace is an old wife's tale as any student of electronics can tell you. Don't do it!

If you mean the wall outlet is switched, then I might agree - well, no! I don't agree with that either, and here's why. It assumes the switch and wall outlet are properly wired and grounded, and not damaged.

I lived in England in the 80's and unlike here in the US, there are people there living in 500 year old houses!!!! They may even have Roman mile markers and hump bridges out front. Pretty cool if you are a history buff, but the point is, regardless where you live, unless the house wiring has been upgraded and tested to be up to code, one must never assume the wall outlet is wired and Earthed properly!

Also, and perhaps more applicable to here, by leaving the cord plugged in, you are relying on a $.50 or £.25 power cord that was mass produced in China to isolate you from deadly voltages. And sadly, and even more applicable, too many computers today use cheap, no-name generic power supplies made under horrendous conditions in some obscure factory by poorly trained, unskilled, often underaged labor, under the supervision of unscrupulous factory owners and corrupt government officials - using components made under the same conditions in a similar factory up river!!!

It is not necessary to "ground" or "earth" electronics to work on electronics unless you must work on "live" electronics. And for cleaning, you don't. What is absolutely essential to prevent a static discharge, however, is for you and the electronics to be at the same potential! And that is done by touching the bare metal of the case (preferably with an approved anti-static wrist-strap). This, in effect, creates what is often called a floating or isolated ground and that is what keeps us from being zapped by electronics in our cars, and by the very high voltages found on flying aircraft.

Even if you have a top quality PSU, and you know your facility wiring is properly grounded and up to code, there are still deadly voltages present. And even the best made electronics have failures and all will fail eventually.

So it is foolish to put your life (and electronics) at risk when all that is necessary is to unplug, and touch bare metal to prevent ESD damage.
***

PS - All wall outlets in the US must have a 3rd connection for grounding too. And all computers use a 3 wire cord that includes a ground wire. That said, there are older homes that may still have only 2 wire outlets as there is no law that forces homeowners to change existing outlets. However, if doing home improvements or repairs, they must get a permit that requires they convert to 3-prong and properly ground to earth, not just to the nearest cold water pipe.

 

Be careful when you clean your computer by using a can of compressed air. Never blow directly into the power supply fan from the inside. I did this and apparently forced dust bunnies into the motor which jammed up the power supply which had to be replaced.

And always hold Any fans with your finger so they don't over rotate when blowing dust which can damage the bearings.

 

Well said Bill & robls99. $10.00 ESD strap is the best safeguard and extreme care not to touch anything with metal objects. Let's see if Dell do as promised. Neil.

 

Hmmm, I think you were just unlucky. I always blast PSUs from the inside out, outside in, and every which way but loose. If dust bunnies jammed the fan motors, then the seals were bad, and the bearings would be failing soon anyway. Good advice however to hold the fans stationary while blasting. You can easily force them to spin faster than designed limits, and that can destroy the bearings as well. You can get a bag of Popsicle sticks from your local crafts store and I use them to hold the fans still. With rounded ends and being made of unfinished wood, there are no sharp points to damage anything, and the unfinished wood will not conduct damaging static electricity.

Also, I recommend taking the computer outside before blasting with compressed air. It means you may have to lug a 50lb box around but there's no need to stir up all that dust indoors only to have the fans draw it back inside. And besides, that dust is mostly hair, dander, microscopic critters that eat dander, and all the fecal matter they leave behind. Makes me sneeze thinking about it.

You may see some folks advise avoiding using an air compressor, stating you risk damaging your computer from too much pressure, flying debris, and all sorts of faulty reasoning. They are naive and misguided. Technicians at professional electronics repair facilities have been using compressors for decades! Your dentist blasts compressed air into your mouth. Bakers use compressors to air-brush and decorate cakes.

There are necessary precautions, of course. The compressor must be of the oilless type. This means you have to add oil manually to use your pneumatic tools that require it, but oh well - you don't want to spew oil on your electronics. The compression process heats the air as it is pumped into the tank. When it cools, moisture in the air condenses on the sides and runs down into the bottom in to nasty pool of rusty water so you must drain it regularly. Even with an oilless compressor and regular draining, oil is used in the manufacturing process, and dust, debris and moisture is drawn into the compressor. So it is essential to use an inline moisture and particulate filter.

You can toggle down the PSI with most compressors. I set mine to 80psi. But if the pressure is factory set above 80psi, just hold the nozzle back an extra few inches.

While on my soapbox, a quick note about cans of compressed dusting gas. Note I did not say "canned air ". That's because it is NOT air! In fact, it is poisonous, typically some form of difluoroethane, harmful if inhaled - and sadly, often abused (huffed - ) by idiots who can't get their hands on a can spray paint.