Replacing capacitors in CFLs (compact fluorescent lamps)

Thread Starter


Joined Jan 4, 2012

I’ve been repairing CFLs and had to replace the capacitors (failed by short-circuit) between the two tube filaments of each lamp. Here you can see schematics to understand which capacitor I’m talking about: (the tube filaments are usually identified as LMP1 and LMP2).

The capacitors are long (“vertical” in relation to the PCB holes, not “horizontal”) and flat, the color seems to be dark green/very dark brown/black (not sure… maybe they get darker from heating during use). From my research, it seems they are 'polyester film' capacitors.

The capacitors I replaced in the two CFLs had this identification:

N1K0 (not sure if the last character is zero or letter O)

I understand that both capacitors are 3.3nF 5% tolerance (letter J), so I replaced both capacitors with 3.3nF 1.2kV capacitors of the same type and also being used in CFL ballasts with the same function (capacitor between filaments) — the goal was to get working CFL lamps by using only salvaged parts instead of buying new ones.

My issues are:
i) Would the lower voltage rating for capacitor 1 replacement be an issue? I ran the lamp for at least 30min-1h and it seems to be working fine (maybe the higher rating is only to better withstand lamp startup transients?). The lamp is a PHILIPS Tornado Esaver 23W.

ii) What is the voltage rating of capacitor 2? I can’t understand from the inscription, but the lamp also seems to be working fine after capacitor replacement. The lamp is a PHILIPS Genie 18W.



Joined Dec 29, 2010
I have only repaired a couple of them and the faults were mostly due to a buldging C4 eletrolytic capacitor (refer to LUXAR 11W schematic) 4.7uF/400V. I didnt go as far as checking the green caps though they look darker than it should be. Some of the named brands lamps use SMD resistors and diodes and the PCBs look very neat and components are easiler to change.

Nice website, very informative and good reference for my future repairs. Thanks.