Help with FML reading lamp please

This is a 27W 4 tube flourescent bulb that fits into a 4-pin holder and has ailed. Replacement bulbs dont work but a mains tester gives power to the female pin holes. I guess its the capacitor? that has failed. I don't see any easy way to remove it (neatly) again guess that it's crimped and snaps in. Removing the heatshrink shows a blue component with no markings.

Advice appreciated please.

Hallo PGK,

As far as I understand there should be an electronic ballast between power input and FML.

I do not see that in your pictures. Is the ballast in the foot of the lamp?

Possibly the ballast should be replaced.

Regards,

Jouke

Edited By Jouke van der Veen on 02/11/2019 14:55:26

Jouke,

You were right, Sir. At that point I hoped it would be some obviously replaceable component but was faced with 2 plastic boxes in the base. Nothing looks obviously charred, swollen or loose but unless there's an off-the-peg replacement ballast then I'm out of my ability/comfort zone

If all else fails, any chance of converting the lampholder to either ES or BC and using a 9W LED? That should provide quite enough light for reading.

Howard

From here I can not advise you how to check if the electronics is still OK. Perhaps you could take more more detailed pictures showing the electronic components and that somebody else can advise how to measure.

It is something for an electronics forum, e.g. circuitsonline.net (Dutch).

Edited By Jouke van der Veen on 02/11/2019 20:33:18

Lamp is my OH's reading/crossword lamp and that suggestion went down like the proverbial. Looking on-line I can replace the whole thing for £25 inc delivery - which I find rather sad.

Jouke,

Thanks for your help but as above the time and my incompetence in tracing through a circuit to repair is hard to justify. I'd hoped it might be a case of just replacing a whole stock ballast unit after you pointed me in the right direction just most of those seem to cost a significant part of the whole item...

I suppose I get a few feet of thin powder coated tube out of the deal and a few feet of flex with a 13amp plug on it

pgk

You could have a closer look at the components first before you decide for your proposal. The pcb is not to difficult. If you recognize some deviation, replace it. Check resistors and diodes for discoloration, capacitors for deformation etc. But be careful when measuring when it is connected to the grid!

The components look normal, no changes that i can determine visually. My abilities with a multimeter are too basic to check them properly.

pgk

Also no discolorations at the soldering side of the board?

Most of times such electronics suffers from continuously overheating..

Why bother with it? You can buy a ' sewing machine light' on Ebay for less than £5. They are fantastic value for money.

I'd be very careful buying a mains powered 'sewing machine light' from other than a European supplier. I bought one from China and fortunately opened it up before I plugged it in. Potential death trap, very skimpy insulation, not double insulated and non earthed metal bits.

If it is a 5v device driven off a wall wart It is probably OK, but check the wall wart is CE marked. If it is mains and comes with a non BS1363 plug don't touch it (literally). I've even been supplied with kit by a UK supplier which had a 3 pin plug with no fuse, hence non compliant

Nothing visible.

A replacement has been ordered. This is a floor standing lamp and cheap enough. Any cheap sewing machine light or similar (I own several Lidl led clip on lights which are excellent for local illumination) would have required a bodge to attach to the stand - not worth it for the saving and the ear-ache.

pgk