Tuesday, January 22, 2013

When There Is No Happy Beep.

While many people have had the misfortune to experience the loss of their personal computer it tends to effect some more than others. For some it is just a minor inconvenience, and yet there are those who greet it as a crippling blow. I awoke yesterday myself to such a discovery. My tower was uncharacteristically silent as I noticed it had shut down during the night. Which didn't immediately warrant any alarm bells as it could of simply updated during the night or my power might have flickered slightly.

What came next I was not prepared for.

I pressed the power button. There was the familiar whirl of fans spinning to life and accompanying them was the illuminated led marking the hard drive spinning up. But, instantly I noticed something missing. You might have expected that the lack of any display on my monitor would of been my cause for concern. It wasn't. Instead, what troubled me was the silence.

Let me explain; when you press the power button on your computer a whole series of things take place that you never actually see. First it checks to ensure it is getting the proper power before waking up the processor. Once it receives the all clear it moves on to the next item on it's agenda, perhaps you have heard of it; the Power On Self Test. It is the job of this POST to verify everything is in working order, and if it is it likes to announce the news via something we techs lovingly refer to as 'the happy beep.' If all is well we hear this singular beep heralding the fact, and if we ever hear more beeps than the one we know there is something afoul in the kingdom.

In a situation such as mine however, there was no beep. So what does that mean? Well, like I said the fans all were spinning so we know power was flowing to the machine. But these things get their power directly from the power supply and tend to be very rudimentary creatures. You push the power button and if the juice flows - they spin. Simple enough. Our issue isn't in getting power it is in the fact that either a.) the power we are getting isn't good enough for the more complex components, or b.) some part of the motherboard/CPU has decided to take it's ball and go home. Permanently.

Now, if it is the former it is easy enough to check. All you need is a digital multimeter, a small piece of wire and a reference as to what wires should be getting what voltage. Might sound like something on an episode of MacGuyver but it's the truth. You can unplug the power connector off your motherboard and using your wire you can trick the power supply into firing up so you can check it. Logically you could do this check with the connector still plugged in to your motherboard but in my experience it is often better to do your checks without sending more voltage to your motherboard if your not sure of it's quality.

Unfortunately, if the power supply isn't your problem then things tend to be very dark indeed. Your processor may have passed away leaving nothing there to wake up. You may even  be the unwilling recipient of a motherboard who cannot send the wake up signal to your CPU. Or maybe... I could go on and on, but sadly the truth is that once you reach this point it is hard to track down. The POST is a vital resource for a technician and if your machine can't even get to that stage, well I don't think it has to be said.

I myself still feel a mixture of mourning and rage about my tower. As an experienced technician this is not a first for me, it's something I have seen before. I can rest fairly safe that my hard drive is intact(knock on wood) and that I have backed up a lot of my important data. But even knowing all that, I still don't know for sure what caused the failure. That single fact will haunt me until I discover it. And while I still have a way to get online and check my email, etc, the loss of my tower is still upsetting. Even now I am contemplating if the capacitors were bulging enough to have be an indicator of failure... Rest assured, a full autopsy is on the agenda.

Some of you can sympathize. Many may not. But in either case the next time you turn on your computer I hope you are greeted by the happy beep.

Update: After some further digging I have found the apparent failure - the motherboard itself. The voltages from the power supply all checked out. I cleared the cmos just in case some fault had occurred within it's settings. I even reseated the processor and inspected it for any visible sign of burns etc. Nothing. But I did one check on a whim, that helped me zero in.

You see, a CPU needs a heat-sink/fan because it generates tremendous heat. So if you remove the heat-sink and power on the system you should be able to feel it warm up. Now I have to caution the casual person from trying this because any longer than a few seconds(about 2 to 5) and you can kiss the CPU goodbye anyways. Plus you can burn your finger as well! My processor remained as cold as ice, meaning no power is ever getting to it. Any conductive material will warm if current passes through it. So if you add these facts together and inspect the capacitors near the processor that regulate the voltage to find them bulging you can safely deduce a cause of death.