Replaced LED Board In 100W Garden Light Model STURLITE IP66
This light belonged to the hospital where I worked and was brought to me in dead condition. I opened the four screws from behind and inserted a blade to detach the top portion from its case, as it was glued. I saw two LED drivers providing the voltages required lighting up two sets of LEDs totaling to 240 nos. (20×12). Kindly use cntrl+upward arrow keys to zoom and view the above pictures. You can perhaps see a few LEDs burnt. I desoldered the LED board and removed the fixing screws and took it out. When I checked the voltages of the LED Drivers, I could read around 54V, which was without any load. Took measurement of the board and hunted for replacements through local as well as online shops.
But none had the correct size. The technology had advanced that high power LED boards were coming with SMD ICs and rectifiers for directly connecting to 230V AC without an external module. I ordered for one. Then used a hotplate to remove the 240 SMD Leds and found it to be cumbersome and consuming a lot of power. So took out the board to my car garage, used a carpenter thistle and chipped out each and every one of them. Used emery paper and smoothed the surface. Here you can see the plate after all these special types of works:
The new board arrived and I checked it applying AC and found it to be working. Applied heat zinc compound on the rear and fixed it on the old board and stuck it with LED backlight fixing double sided tapes.
I also drilled holes to put screws so as to ensure that the new board was firmly and evenly stuck to the old board. Then fixed the board to the cabinet and soldered the AC input wires.
I had tested it after connecting and found it working, before I fixed the front and back covers. The light was providing brilliant illumination and I was happy to see that the experiment really worked. I really wondered how these Chinese guys developed such tiny ICs that can deliver the power required! Anyhow, mission accomplished getting satisfaction gathered to its collection!
The electrical staff at the hospital was very happy to have got back the light fixed.
I am yet to raise my bill for this work, though it was completed on 25th August, 2023. (I am writing this article in October!)
This article was prepared for you by Parasuraman Subramanian from India. He is 72 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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Albert van Bemmelen
November 12, 2023 at 6:34 pm
Good to see that you still could replace the unfixable 240 leds containing board although maybe only 2 leds of this ledboard were bad. I guess that from all the with a carpenter thistle chipped out leds most couldn't be used anymore. If such repairs ever happen to cross my path I do hope that my 230VAC 850 Watt Uyue 946c hotplate will do the trick in pre-heating the board to about 350 degrees Celsius at maximum enabling me to remove any bad led. This one:
The power label sticker on the back of the Uyue case wrongly mentions 600 Watt although the advert mentions 850 Watt! (I measured about 824 Watt)
Parasuraman S
November 12, 2023 at 8:41 pm
Many thanks for your expert comments and tips!
Imoudu.O
November 12, 2023 at 10:12 pm
I don't really get the reason why you have to remove all leds on led board since you intent to replace it with another led board of 210 leds.Thanks for sharing sir.
Parasuraman S
November 13, 2023 at 5:35 pm
That was to use that aluminium sheet as additional heat dissipator! Many thanks!
Arunkant L Pandit
November 13, 2023 at 1:25 am
Good job sir. The MCPCB replaced is popularary known as DOB (Driver On Board). Better version of this MCPCB is ALFA DOB.
Parasuraman S
November 13, 2023 at 5:36 pm
Many thanks for your tips!
Yogesh Panchal
November 13, 2023 at 3:52 pm
Good Modification Sir.
"SHUBH DIWALI" to you and your family.
Parasuraman S
November 13, 2023 at 11:08 pm
Many thanks, dear! Same to you too!
Henrique J. G. Ulbrich
November 13, 2023 at 9:50 pm
Excellent, Parasuraman. Thanks for sharing. I´ve already maintained such reflectors, and I consider that one of the most important steps in the maintenance work is to remove the old thermal paste (commonly insuficient and already dry), sand/clean the surface and apply a new thermal paste, in enough quantity. This is a dishonest trick used by the manufacturers: to put a few quantities of thermal paste to reduce the useful life of the product. Not all people try to repair the reflector - they opt to throw away and buy a new one. And a reflector that could be easily repaired goes to the landfill.
One comment about the voltage measured at the output of the driver: the voltage measured is just an evidence that the driver is working; it is not the real feeding of the LED panel, as it works with constant current, which means that the voltage is adjusted so as to meet the current requirement. The LEDs are designed to operate at a fixed current, that is just the task of the driver
Parasuraman S
November 14, 2023 at 9:42 am
Many thanks for your expert comments and valuable tips! I fully agree with you!