Common failure is broken capacitor C3. It is possible mainly at cheap lamps, where are used cheaper components for lower voltage. Whet the pipe doesn't lights up on time, there are risk of destroying transistors Q1 and Q2 and next resistors R1, R2, R3 and R5. When lamp starts, changer is very overloaded and transistors usually doesn't survive longer temperature overloading. When the pipe serve out, electronics is usually destroyed too.
When the pipe is old, there can be overburned one of filaments and lamp doesn't lights up anymore. Electronics usually survives.
Sometimes can be pipe broken due to internal tension and temperature difference. Most frequently lamp fails, when power on.
Repair of electronics
Repair of electronics usually means change of capacitor C3 if he is brobek. When burns fuse, probably will be damaged transistors Q1, Q2 and resistors R1, R2, R3, R5. You can replace fuse with resistor 0R5. Failures can be multiplied. For example, when is shorted capacitor there can be thermally overloaded transistors and will be destroyed. Best transistors for replacing of original types are MJE13003, but it is not easy to find them. I replaced them with BD129, but they are not available now. There exists other variants like a 2SC2611, 2SC2482, BD128, BD127, but I am not sure if they will be long-life. Original transistors are not available on our market. If doesn't matter size of case TO220, it's possible to use transistors MJE13007.
Lamp is usually compounded of two parts. One is plastic cover with holes for pipe and bills. Tube is agglutinated to it.
Second much bigger piece has slots for bills from the inner side. Inside is printed circuit board with components and wires from tube. From the upper side of PCB are wires to top of lamp, where are soldered or stamped to the contact. Both plastic parts are clicked to himself and sometimes glued. Usually you can carefully leverage with a small screwdriver sequently to round to the gap between both plastic pieces for releasing of glue. Next you must leverage more to the opening lamp. For closing of lamp you can only click both plastic pieces to himself. Look at photo of opened lamp.
Most of these compact fluorescent lamps use same or very similar wiring. more expensive lamps use a little complicated wiring with electrode preheating and thanks to it they have longer lifetime. Repairing of these lamps not pay off, because price of cheaper types are very low now and price of human work is much higher. Wiring diagrams originates while repairing of lamps and they are only for study or repair uses. Informations are from retracing of lamps and from sources in a link section.
- http://www.simandl.cz/stranky/elektro/starter/starter.htm Page with a description of electronic starter in a Czech language.
- http://eu.st.com/stonline/books/pdf/docs/3706.pdf ST | ELECTRONIC FLOURESCENT LAMP BALLAST
Schematics and photos
Compact fluorescent lamp Bigluz 20W use classic wiring with a small changes. Values of parts are modified for bigger power.
Click for enlarge
Photo of opened lamp Bigluz 20W.
Click for enlarge
Lamp Isotronic 11W use a little modified wiring, where doesn't exists starting circuit with a diac. Lamp starts probably thanks to capacitor C1.
Lamp Luxtek 8W use classic wiring with a small changes. Interesting is only thermistor, which probably makes light start and filament preheating.
Photo of board with a electronics and upper side of cover.
Lamp Maway 11W use different wiring too like Isotronic lamp.
Lamp Maxilux 15W use classic wiring.
Lamp Polaris 11W has a small thread and changes some values of components. Wiring is classic.
BrownieX 20W lamp has a simplified wiring like a Isotronic lamp.
PHILIPS ECOTONE 11W
Lamp PHILIPS ECOTONE 11W use again simplified wiring like a Isotronic lamp.
This lamp compared to other has a right dimensed components, that electronics probably can live longer. Wiring is less cheated than others. It has coil L2 for blocking HF interference and capacitor C1 for voltage 1200V, which is very much stressed. Tube is superior compared to a no-name types. Light color "warm white" brings light of classic bulb and doesn't have a small pink tone like others. Tube is a little longer and have much light compared to others 11W types. All these lamps, which I have from several series have identical color tone and brilliance. Compared to lamps MAWAY, where every item have different color tone, some have destroyed electronics, some have pipe with a lost vacuum etc... It is seen, that lamps from marked manufacturers have guaranteed parameters and better quality than no-name.
Photography of opened Philips lamp.
Lamp IKEA 7W has classic wiring like a Lixar 11W.
Component values are modified to a lower power. Parts are enough voltage dimensed. Failure was overburned one of filaments. Lamp was on continuous for one year, which is over 8500 hours. Life time corresponds to a label specifications.
Photography of opened lamp IKEA 7W
OSRAM DULUX EL 11W
Lamp OSRAM DULUX EL 11W has again classic wiring with only few changes. She has a small thread and was a fully functional.
OSRAM DULUX EL 21W
Lamp OSRAM DULUX EL 21W has a classic wiring diagram. In contrast to a previous OSRAM lamp doesn't have thermistor for slow start. She has overburned one filament.
EUROLITE 23W (October 13 2008)
Lamp EUROLITE 23W has a classic wiring diagram. For schematics thanks to Mard.
SINECAN 5 2x 26-30W (October 13 2008)
Electronic ballast SINECAN 5 for two fluorescent tubes has identical circuit like most of compact fluorescent lamps. Little differency is in powering tubes before D6 diode and wiring of start capacitors C10 a C11 about tubes. I don't understand exactly why this is wired this way. Ballast doesn't have fuse, but only thin wire. Ballasts was broken due to blowed electrolytic capacitors. It breaks transistors and resistors R3, R4, R5 and R6.
Photography of open ballast.