The capacitor and ballast may have specific temperature ratings, but most effects  of temperature (ie. short of the electrolyte freezing solid) are gradual, and the point of cutoff chosen for the rating is fairly arbitrary

Together with additional factors - age of components, resistive condensate films forming (including on the tube), and other abnormal conditions, the actual non working range may end up within the rated range



For example :

Consider a ciruict where the small chip Vcc electrolytic is charging from the rectified line voltage through some high (in the Megs range) resistor. The current supplied by the resistor is not sufficient for the continuous operation of the chip

The chip has undervoltage with hysteresis. Once the cap charged to the high level of this hysteresis window, the chip starts using it, and there is enough energy in the cap, that the chip can start running the circuit before the cap discharges to the low level

What if the cap discharges so quickly (e.e due to capacity loss) or has so high voltage drop (due to ESR), that the chip never gets its starting voltage for long enough time to even generate the 1st output pulse. The circuit will appear dead, the power draw of the circuit will remain basically VRectifiedLine / Resistor



Measure whats up with the voltage on this cap. Evan if you dont have a scope, just DMM can give a general indication

Chokes mostly fail as result of stuck starers, but an F4T5 have so low arc voltage that i doubt the stuck starter current would differ much from normal operation current with an F4T5 anyway

Same result could be achieved with some intentional assymetry between the 2 windings in a standard low-leakage transformer, wouldn't it ?

I haven't come around to checking out my SRS ballast, however i do wonder. The old Eltam SRS ballasts were based on Mini U core and winding formats. I don't know whether they even had the ability to make a high leakage transformer there, as was added in the B series

Do you have an oscilloscope?

What is the voltage measured over main DC bus capacitor?

What is the name of main control chip, some Philps UBAxxxx have open datasheets.

I believe the HF performers are rated for operation down to -20°C.

Today I bought two new ones, I gave up troubleshooting the one that was acting weird heh, instead, I've desoldered and tested every suspect component. I can't find anything wrong with any of them. I even checked the resonance capacitor, the main switching transistors, etc, and they're all fine. I think there might be a micro fracture in one of the solder traces on the board, because in some spots it looks slightly delaminated. Weird, this ballast has only about 2000 hours on it! But it is one of the earliest HF performers they made. I know they had some problems with the early generation.

The ones I got today are generation 3, which supposedly doesn't have any issues like this

I'll mount one of them and get the fixture back up and running this weekend.

But, I still want so badly to know what happened to my original HF performer.

Sometimes.

@dor123, that video was interesting. Does Israel often see severe thunderstorms like what we get here in America?

You said -5degC, that is not a "normal" range for generic electronics.
Is the ballast rated for this temperature? If not, that could be the main problem.
Because standard electrolytics (those explicitely not rated for freezing temperatures) increase their ESR rapidly once the temperature crosses 0degC (the electrolyte inside freezes, so stop being conductive, so won't provide the connection to the functional dielectric surface). Even when they are perfectly good - it is just their functional property.
So in such case the 0degC is really a limit where the function tends to deteriorate very steeply, it is literally water freezing inside of the components...

There are electrolytic capacitors rated down to -40degC, but they are explicitly rated for that range.

And even if so, to test they are good, you need to cool down the electrolytics to that low temperature (at least -5degC, where the system is acting up), higher temperature may mask out the high ESR failure and the capacitor may appear good when tested, even when in reality it is completely bad.

The temperature is about -5°C right now outside, so we're not talking about crazy low temps. They should work down to -15°C, probably even colder, without any issue whatsoever. So we're definitely not outside of the temperature range here. The 49W tubes are pretty easy to strike in the cold from experience with other fixtures, and they seem to warm up pretty quick in enclosed luminaries like mine at home which is the one behaving weird.

I think my approach will be checking the main electrolytes with the heat gun. If that doesn't give any positive result, I'll try the resonance capacitor. The resonance cap is actually somewhat suspect already, because the tubes have what I'd call severe end blackening after just about 1000-2000 hours. That's literally nothing. I'd expect this level of end blackening at maybe 40000-50000 hours. I'll dig into it more after work today, I really want to learn what's wrong with it! and I want to fix it!


Yes indeed film caps do fail, and to be honest, I think that's what has happened somewhere! The elevtrolytics both checked fine :O

It is not only the LEDs, but over the history of artificial lighting, the more efficient and so cheaper to run light sources became, the more light people used to make with them. Even to the extend to actually spend more money for the lighting (even when accounted for inflation). I do not see any reason why this behavior would ever stop with LEDs...