Alex Mac

Hi there,
my names Alex
It seems forums have helped me out a lot in other areas so I thought it was worth a go with electronics!

I'm by no means an expert though have a rough knowledge and am keen to tackle more electronic fixes myself.

I'm currently trying to change over a couple of capacitors on a BMW instrument cluster. Theres various that are prone to faults (22uF 40v / 220uF 10v / 220uF 16v) I'm unclear as to whether or not they are functioning correctly. They do not apper to have blown / exploded and unfortunately my multimeter doesn't have a capacitance test function!

It seems I cant get ahold of the exact ratings (can find higher voltage limits - does this matter?) also the size seems to have shrunk over the years, meaning the position for the prongs on the PCB is different to that of the new caps.

Anyway - I guess Im wondering where the best place to get a variey of spares is in the UK? I work with sound and lighting equipment for performances and often come accross broken equipment that I would like to be able to repair. I'm also into cars and mechanics however this is the first time I've attempted repairing soemthing more complex. (I dont even know if these caps are faulty or if its something else? Im just following an article posted by somebody else! http://bmwe32.masscom.net/
(follow Fixes>Electronics>Dash Cluster Caps)

The dash seems to work for a while then start playing up / the digital display cuts out and restarts several times! and depressing the brake pedal interferes with the dash somehow?!

[b]Anyway I've rambled enough for the while.Any info on my latest issue would be great.Also info / advice on best suppliers and / or other forums / people to talk to in the UK!Advice on what tools I may need / building up some useful supplies etcand general hellos and so on would be great!

Cheers Alex Bimringham, UK
[\B]

JimB

Electrolytic capacitors can "dry out" over time when used in a hot environment, often there is a light yellow/brown "crud" where the leads enter to body of the capacitor, a sure indication that they are drying out.
Dont worry about not being able to measure the capacitance, not many people can and it is not usually a problem.

No, not usually.
If the capacitor is filtering or decoupling a supply line not a problem.
If the capacitor is part of a timing circuit, then you need the correct value.
However, electrolytic capacitors have a wide tolerance, usually -20% to +100%, for your application, just go with what you can get.

That is progress for you!
Get the nearest size you can and carefully bend the leads to fit in the holes on the PCB.

You could try Maplins, but dont blame me if the oik behind the counter would not know a capacitor if he ate one.
Rapid Electronics
Farnell
RS Components
But note that RS and Farnell are suppliers to industry and may have a big minimum order value.

There are other suppliers, I am sure someone here will chip in with a better suggestion.

JimB

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