Electronic Ballast LGT8236D-A2 - Repair

[electronbean]

How should I test this electronic ballast? I should probe between pin 1 and pin 3 and get 230VAC? (see this image: https://ibb.co/dK5pRsg)

This electronic ballast crashed after I switch lamp to other (wrong lamp). The wrong lamp blink and after this didn't work and the other correct lamp doesn't work either. (after first wrong lamp I went to the shop and buy a correct lamp).

I tear down the electronic ballast (see this image: https://ibb.co/V9byYgz and https://ibb.co/sQJCH8g) and tried detect which component fail. I think the problem is on TBJ 13007 (see this image: https://ibb.co/m8PrCZY). I measurement between pins and get this values (see this image https://ibb.co/Ptzgmp3):

• 2 and 5 = Collector
• 3 and 4 = Base
• 1 and 6 = Emitter

• U32=360V
• U12=360V
• U45=0V
• U56=128V

Any thought what can I do and try to fix this equipment?

Thank you in advance.

[fzabkar]

It's probably an MJE13007 or one of its many clones.

http://www.unisonic.com.tw/datasheet/MJE13007.pdf

I found some application notes that might help:

https://www.st.com/resource/en/application_note/an527-electronic-fluorescent-lamp-ballast-stmicroelectronics.pdf

https://www.onsemi.com/pub/Collateral/AN1543-D.PDF

[electronbean]

Thank you for your reply and help.

Do you think the problem could be from transistor?

[fzabkar]

You need to test the transistor using the diode range of your meter.

[electronbean]

Can I test the transistor directly on the board? Or I should desoldering the component before test them?

[fzabkar]

Can I test the transistor directly on the board? Or I should desoldering the component before test them?

Test it on the board first.

[Tantratron]

Back in 2019, I had tested and compared 4 ballasts model for a customer for 58W fluo lamp about special R&D project. Yours are for 36W fluo lamp but it does not matter in your repair. The 4 ballasts were HowLong, Sylvania, Osram and Philips, some are instant starts, other cannot work if not attaching 2 fluo tubes.

The good news for you, the HowLong is very special circuit which you can run only one fluo tube and short the filaments plus it has an analog PFC (no chipset used) so old school ballast which you can tweak.

N.B. When you did connect the ballast prior the failure, did you connect one or two fluo tubes ?