13007 Power Transistor, Faulty Diodes and a Capacitor Found In Self Made LED Porch Light
This is a generally available Power Supply that can take around 2A load usually used for LED Serial Lights. I had bought one along with a ready made strip of LED lights for use in my Car Porch. This has been working fine for the last two years. But suddenly went dead, tripping the MCB. So removed it and checked what went wrong, after thorough cleaning. I had provided grill to prevent any gecko doing any exploration. Though the grill was having very small pores, the unit was almost packed with very small dead insects, which find its way through.
On opening and checking the components on the board, I could see that the fuse was cracked; all the four rectifier diodes were short along with the 13007 transistor. The tank capacitor, 33/450V was showing zero ESR and on removing it, I could see that it was rusted and corroded at one pin, due to leakage. These were indications of high voltage surge and moisture formation. Replaced the defective components and checked for any more defects and could not find any.
Since exact size of fuse was not available, used a slightly large one, covering it with a protective sleeve and marking its value on top of it. Powered the PS through a series bulb and found it to be working. So assembled it back and retested it.
Plugged it back on the car porch and checked it again.
These are the defective components:
Work completed and added to my ‘SL’!
This article was prepared for you by Parasuraman Subramanian from India. He is 69 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.
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