Computer running slowly and/or crashing

 Is your computer driving you round the bend?

Are you tempted to just chuck it through the window?

If so it's highly likely, if it's more than a couple or more years old, it's highly likely that the designers of the motherboard are to blame.

Let me explain...

All computer motherboards use high value capacitors of one kind or another: most likely electrolytic capacitors.

The motherboard designer will have specified the particular ones he thought were best suited to cope with his requirement, but either ignored one or more of the key parameters, or just couldn't be bothered as any shortcomings would not show up for a few years.

Capacitors are used in a computer motherboard to maintain a nice clean supply voltage so that the various components will work correctly.

A little specified capacitor parameter is its lifetime. The harder a capacitor works to do its job the hotter it will get and the shorter its life. Capacitor lifetime is a relatively new parameter. In days gone by, all things being equal, a capacitor would last for ever and no-one bothered to calculate lifetime.

Not so nowadays however. In order to produce the smallest overall size, commensurate with capacitance and working voltage, capacitor manufacturers have come up with more efficient electrolytes.

Some of these products don't perform too well when heated resulting in problems.

Eventually such a capacitor will begin to fail.

Increased pressure inside its sealed can would eventually make it explode if it wasn't for a design contingency normally visible as a scored cross on the top of the case.

The cross makes the capacitor can weaker at this point and, when the metal fails, instead of an explosion, you'll see electrolyte leakage. This is sometimes a brown residue sitting on the bright aluminium of the can.

Sometimes the cross will remain intact and pressure will force electrolyte down the sides of the connection leads. This is really bad news as most electrolytes are highly corrosive and will attack the printed circuit.

High spec boards nowadays may use "solid" capacitors or "Military" parts which of course signals the manufacturers' knowledge of their designers' previous shortcomings.

So, if your computer is acting strangely, and is more than 3 years old.

Say its working very slowly, freezing sporadically or giving blue screen displays... forget about so-called driver issues and Microsoft reports etc and first remove the side cover and peer inside.

Identify the processor. This is the thing under the fan.

Around the processor you'll see lots of cylindrical components with bright aluminium tops, often with scored crosses.

See if any look different from others, for example have bulging tops or have a deposit of brown gunge sitting on their tops.

If you have a keen sense of smell and, depending on the particular make of capacitor, you might be able to detect an odd smell, something like ammonia.

If you see anything untoward then your computer problems may be caused by a capacitor short circuiting one of the low voltage supplies. There's so much current available in the power supply that any short will instantly disappear, however the effect of the short circuit may result in one of the programs going badly wrong and this may result in anything from a freeze to a blue screen.

A nasty side effect might be data corruption making the computer unreliable until the corrupted data is fixed.

Lots of people merely attempt to cure the effects of bad capacitors. Fixing bad data or bad programs may make an affected computer work normally for a short time... until the next short circuit anyway..

There are two solutions. Fit a new motherboard or replace the bad capacitors.

The former solution is often very tricky if an identical motherboard isn't fitted, so at least try and find a replacement using a similar chipset.

The latter solution is the most reliable if you can find someone that can fit new capacitors. This is a difficult task, but once done will provide a few years extra life to your computer.

 

Sooner or later your computer power supply will fail also.

All power supplies use electrolytic capacitors and these too eventually go bad, although the power supply is generally more robust than your motherboard.

Most power supplies are cheap and are best replaced.

 

Does anything else use capacitors?

Yes, your TV set, set top boxes, hi-fi equipment, washing machines etc. In fact anything electrical.

Did I mention light bulbs?

Low energy lamps use capacitors and these fail a lot sooner than the manufacturer would like to admit... so just forget about any stupid claims for lifetime of lamps.

That also goes for any of these new fangled solar arrays, wind powered generators and the like. Many controllers will fail long before the manufacturers' MTBF...

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