Electronic Ballast issue

[steinklatre]

Symptoms were: Light didn't work. If I unplugged or plugged in the light from the ballast the light would flicker then go out. Checked the bulb by buying a new one same issue.

The ballasts are kinda expensive and not local so wanted to see if I could fix this one.

Model: VIVA VEB82155
55W 120V 60Hz 880mA

So I posted some pics and scoured this thing for obvious signs of damage but I got nothing. Where to start?

 

[CocaCola]

Have you looked at the cost of a similar replacement light, not the fancy ones just the bare bones light that uses the same bulbs? Even if it's just used to rip the ballast out to use in your existing light? You might be able to find a damaged open box or display model at the local hardware store that you can get cheap and rip the ballast out of...

I did a job for a retail store that had a bunch of aging lighting ballast that the owner wanted the ballast swapped vs changing out the entire light... $ for $ it was cheaper for me to go to the local hardware store and purchase the cheapest comparable rated fixtures and gut the ballast out of them vs purchasing replacement ballast...

 

[steinklatre]

CocaCola, I thought about it but they are square fixtures for a drop ceiling in the basement so Id have to cut a new ceiling tile as well. That's the only pain part. They are nice looking fixtures too.

 

[CocaCola]

CocaCola, I thought about it but they are square fixtures for a drop ceiling in the basement so Id have to cut a new ceiling tile as well. That's the only pain part. They are nice looking fixtures too.

I not suggesting replacing the fixtures, just purchasing a new equivalent rated fixture to yank the ballast out of as in many cases you can purchase a new fixture cheaper than just the ballast...

 

[steinklatre]

Ok I am following you on this. Ill go to Home Depot tomorrow and search it down. Now how would I even start on troubleshooting something like this? Seems like it would be a needle in a haystack! I am pursuing my Electrical Engineering degree with a major in electronics but haven't hit the major stuff yet....

 

[CocaCola]

Well the first place I would look is at the fuse followed by a visible inspection of the traces and components for obvious signs of damage that might lead you right to damaged component or area of damage... Second place I would look would be the upright IC (transistors?) followed by the smaller transistors... From there I would move to the transformers... And then to the electrolytic capacitors...

This is one of those cases where (since I don't have unlimited free time) that I weigh in how much time I would waste finding the fault vs how much time I can actually do something productive that pays and simply pay to replace the part... IMO if the fault is not obvious the scale tips heavily into the replace the unit vs fix...

 

[debe]

What ive found in electronic ballasts is the Mains filter capacitor after the rectifiers dries out. replacing it sometimes restores them. Worth a try.

 

[CocaCola]

What ive found in electronic ballasts is the Mains filter capacitor after the rectifiers dries out. replacing it sometimes restores them. Worth a try.

As always if you have troubleshot them before and know common points of failure you can also use that knowledge, replacing the caps certainly is a cheap option, might be worth the effort...

 

[steinklatre]

Well the first place I would look is at the fuse followed by a visible inspection of the traces and components for obvious signs of damage that might lead you right to damaged component or area of damage... Second place I would look would be the upright IC (transistors?) followed by the smaller transistors... From there I would move to the transformers... And then to the electrolytic capacitors...

This is one of those cases where (since I don't have unlimited free time) that I weigh in how much time I would waste finding the fault vs how much time I can actually do something productive that pays and simply pay to replace the part... IMO if the fault is not obvious the scale tips heavily into the replace the unit vs fix...

I definitely know what you mean. Honestly It is a bit fun learning and using all the expensive gear I have gathered for work/future fun! Not to mention the satisfaction that comes from learning! Whats killing me is there is no obvious signs no shorts in the wires no burns no leaking etc etc...

 

[Bob McDowell]

I had this same problem and it turned out to be an inadequate ground. Clean the paint off of the fixture where it grounds to insure a good connection and then try it. It ruined my ballast and I had to replace it, but after I cleaned the ground, no more problems.
Good luck.

 

[quantumtangles]

If you follow cocacola's advice (checking fuses, ICs, electrolytic caps etc...I would have bet on the latter having failed but apparently not) and the problem remains, then it is something exotic...relatively rare. I am thinking one of the film capacitors may have failed. It should be relatively straightforward to check the capacitance of the film capacitors if you have an ESR meter. Unlike electrolytic capacitors which fail in obvious ways (yet can retain capacitance), failed film caps look perfect on the outside but have capacitance values way outside their rated levels. Incidentally, if the electrolytic caps are CAPXON brand, I would replace them all immediately as a preliminary issue. Even if they are ok now, as they appear to be, CAPXON electrolytics are dreadful and will soon fail anyway so its always best to replace them on sight (shoot CAPXONs on sight). Also, those tiny heatsinks may not have been able to keep the ICs cool enough and they may not have automatic thermal shutdown capability so a quick look at the datasheet for the ICs (do they have thermal shutdown or not) may be helpful. If they dont, they could easily have burnt out.

But I am going out on a limb here and suggesting the film caps may be out. In case you do not believe film cap failure is a viable possibility, you are in excellent company alongside the famous Aussie and talented engineer behind the EEVBLOG and here is the youtube video to prove it

 

[(*steve*)]

Oh yeah, greencap failure.

As he says, they don't normally fail. BUT unlike X or X2 (etc) rated capacitors, when they fail, they don't fail "safely".

Typically ends up as shorted (as Dave says).

And as we see, it has been used across the mains. A great argument for using X rated capacitors.

In this application (with greencaps) I've seen things explode, and fortunately the greencap didn't go short circuit!

Also note, he didn't use an ESR meter to check the capacitance -- he used a capacitance meter

I'm surprised he didn't mention the use of a non-mains rated capacitor in a mains application...

 

[MarcD]

Your best bet is to go to an electrical supply house and tell them what size and type blub you are powering. make sure new ballest will fit and any possible minor wiring changes within fixture may or may not be needed. The old ones we grew up with have been long gone for some time now. be careful when buying cheap bulk lights from home centers. One time I had 3 bad ballests out of nine lights, but look where all this crap comes from, all due respect. Also, our power is not that clean.