Help or advise for diagnosing Verilux floor fluorecent lamp controller.

[Benny7440]

A few months ago someone gave me a supposedly good Sylvania lamp and after trying to find some info in the web about it decided to open it to check its inner components, if any, because I found nothing useful at the web. Apart from the plastic cover nothing has been damaged.

A few weeks went by and the old Verilux floor lamp at the kitchen started to turn off a few seconds after turned on. Before this I almost always had to touch or press a little the lamp for it turning on. This is a three illumination level lamp via a switch. After about a week of this new behaviour the lamp stopped turning on completely. I suspected the lamp itself and remembered the opened one but needed some info on how to connect it because even though they both have almost equal wattage characteristics the physical layout are incompatible. When I reached for the almost inaccessible plug my theoretical ideas ended: I saw and remembered the black box titled controller!

Immediately, I realized that the circuitry inside, for its complexity, might be a better candidate for the culprit. Today I opened the controller box suspecting that there might be a 'fuse' blown out. I was right about the fuse but it wasn' blown out.
Sadly, I also I discovered that with the saw I had severed some wires from a little transformer which needs to be replaced (haven't checked between some old stuff that I keep around for the sake of having parts at hand in case I need them).

By the way, I now realized that at my presentation I failed to include that I used to work for DEC as an electronic tech for five and a hafl years ending at 1982.

Even though I still need to find a suitable xformer I'm going to ask how to substitute one lamp for the other? I'm about to include an attachment with a photo that includes the following:
1) Sylvania - Dulux D/E 26 W lamp : the thinner one;
2) a China made lamp of 27 W, model: 27WKFDL27EX-CW : the one that looks as four capital letter I;
3) the bottom of the lamp that shows its sticker as well as the four-pin plug that goes into the controller.

Sorry that with this cheap tablet couldn't take a better photo including the controller! As long as my sister allows it I'll be able to take a digital photo and upload it to you, but if she needs it I will need to return the tablet to her.

Thanks in advance for any kind help on the above!

PS. I know, the original issue hasn't been addressed yet, but unfortunately I need to repair first what I broke before been able even to take some dynamic measurements. Keep in mind that my only useful diagnostic tool right now is a digital multimeter.

 

[Tha fios agaibh]

Not really worth screwing with imo.
Buy a 27w cfl ballast and install it.
It will run about $15 dollars US.

 

[Benny7440]

Thanks for replying, Tha fios agaibh!

First of all, what's the meaning of "imo"?

Your advise is very logical but then what's going to be the relevance of diagnostics? Once in a while I feel the necessity of brushing off the rust on my tech-gained experience and, whenever something stop working, that I take as my queu.

Most of my experience was around Power Supplies and with a variety of digital modules (cpu's, interfaces, etc.) at DEC. Understanding a design (theory of operation of a circuit) is in itself rewarding even if one never gets to complete a repair.

I chosed this post as an introduction into the forum not because it is the most important thing that I need to repair but because it is something that covers a blurred area for me and, logically, it offers a good opportunity for learning.

 

[Tha fios agaibh]

Thanks for replying, Tha fios agaibh!

First of all, what's the meaning of "imo"?

Your advise is very logical but then what's going to be the relevance of diagnostics? Once in a while I feel the necessity of brushing off the rust on my tech-gained experience and, whenever something stop working, that I take as my queu.

Most of my experience was around Power Supplies and with a variety of digital modules (cpu's, interfaces, etc.) at DEC. Understanding a design (theory of operation of a circuit) is in itself rewarding even if one never gets to complete a repair.

I chosed this post as an introduction into the forum not because it is the most important thing that I need to repair but because it is something that covers a blurred area for me and, logically, it offers a good opportunity for learning.

Imo= In my opinion.

If its something your dedicated to diagnosing,...More power to ya. I respect your ambition.

But usually the components in a starting ballast circuit are potted making them inaccessible. Even if you get access to the board, your probably dealing with tiny smd components that are difficult to work with. (At least for me)
If this lamp has a circuit board that's accessible and you can post some detailed pictures, perhaps we can help you figure it out. (I'm no expert myself)
If you find a schematic, even better.
On the other hand, If your dealing with something inaccessible, your in for a big challenge.

John

 

[Benny7440]

Since I'm using a cheap front-facing camera on a cheap tablet the photos aren'n good, sorry. All the components are readily reachable on both sides of the board.

PS. I might do better with the photos if you need them to be better, only need to prepare a suitable jig and wait for the wind to calm down and the sun to strike unobstructed by the clouds.

 

[Tha fios agaibh]

You could start by checking the diodes and then the electrolytic caps with an ESR meter. Those smd transistors on the back are suspect. (Q1,Q4)
You might need a hot air gun for dealing with smd components.

 

[Benny7440]

Due to my lack of experience in using this camera I might have induced an error in your appreciation of components at the back of the board: there is no transistor there, only diodes!

I tried again to take a better photo of the top of the board which I'm uploading next. Hopefully, you'll be better at judging what components are there.



All the components that I could measure from the top side are good (fuse, cables, the 2 electrollitic caps, 3 diodes and another cap). At the back side there's a kind of lacquer coating but by piercing hard enough managed to take all the readings, which appeared to be in-bounds.

I didn't attempted to take any readings from the main xformer leads, yet; I'll be focused in finding a substitute for the broken one ( at the lower-right corner in the last photo).

There's a mystery component right at the left side of the main xformer but I'm not taking any action around it, for now. I'll post again as soon as I replace the damaged part.

BTW, is there another form of lighting this lamp even though it's life expectancy is reduced?

 

[Tha fios agaibh]

Sorry, pictures a little grainy for me.
I expect two transistors somewhere.
You can probably find a inductive ballast alternatively.
Good luck on your transformer query. What was the damage? Melted (shorted) windings?