Trying to identify & source a capacitor.

Thanks for that. I googled for all I could think of. Lighting capacitor did not occur to me. Is there any difference tween a a motor & lighting capacitor? Nick.

Different mounting usually, possibly higher duty cycle.

as a matter of interest, all you should see on a multimeter is a very short kick when you reverse the probes. I'd be very worried if it actually read as a resistance.

So are you sure its dead?. If there is a choke as well, I've had those just die for no apparent reason and completely screw the thing up. In the end it might be more cost effective to take the guts out and install a solid state ballast instead. Brian

What's wrong with the light? That cap is likely to be for power factor correction only and the light should work perfectly well without it - unless the cap has gone s/c, in which case just disconnect it.

If the light isn't working for some other reason it would be better to throw away choke and cap and spend your money on a new HF ballast, such as

If the light is not working and someone has told the OP that it may be the starter capacitor should he instead be looking for something like this

in his installation. In my experience a very likely cause of a florescent light not working.

I thought 2D didn't use those canned starters.

The 4uF cap is most probably a pfc cap, if so it doesnt need to be there at all.

NT

That's true enough. I've been meaning to refit the 4.7uF PFC cap that I 'borrowed' from a 2 foot quickstart fitting in what was originally the 'Coal Bunker" in my basement these past few years now. It seems to work just fine without it (20W is the upper limit for uncorrected PF on a fluorescent lamp ballast according to the regs the last time I looked).

However, I did notice that its starting performance became very sluggish when I did that, sometimes taking several minutes to 'spring into life'. It's not so bad now since I cracked open the basement window to reduce the RH and clear the dampness out.

Since reducing the RH somewhat, I no longer have to (literally!) lend a hand to the 4 foot tube in the main part of the basement to assist its startup (also in a quickstart transformer choke ballasted fitting) which now turns on in an instant no matter how cold.

It seems, in retrospect, that high levels of humidity have a deletorious effect on startup performance of a quickstart ballast circuit.

For new equipment on retail sale, yes. Of no relevance to domestic users.

NT