DOB LED Circuit Replaced
A friend of mine called me he wants to meet me for some lighting device fix. I told him you can bring it to me, he is staying far from my location but he frequently visits my nearby location for his work.
So after two days he visited my place but I did not found any equipment in his hand …so I asked him you want to repair something but seems you forgot to bring…. He laughed at me & told off course I am having it with me & he put his hand in his trousers pocket & bring out small circuit.
Seems It was used in some decorative device. On asking him he told me the part is belong to Decorative Ceiling CHANDELIER it is bigger in size hence he brought only defective circuit to me.
So I took the PCB for checking physical condition & instantly I found burnt & degraded LEDs. Symptom: On starting DOB Light working OK but after few minutes it gets very dim.
This circuit is known as DOB – (Driver On Board), Because PCB is having driver IC & other parts in build so additional Power adaptor is not required. we can run this Circuit Directly On 230v AC supply.
Normally technicians remove LED & making jumper to LED or putting 1k resistor or connect 1w LED, it is not advisable it will damage some more leds in short time period & also it don’t last for long.
First I decided to replace 3 damaged LEDs, on searching in my junk boxes I didn’t found any as replacement. As this DOB is rated 5W and total 12 Led is connected so each LED is of approx. 0.4W. The 2835 LED chip 2.8mm x 3.5mm in size. This DOB having Warm White LEDs
So instead of changing LEDs I brought WARM White DOB PCB from my nearby part supplier.
So removed wires from old DOB & connected new DOB & tested.
After confirming removed old DOB Heatsink for putting new DOB on it.
Applied white silicon thermal paste on new DOB & placed it over Aluminum heatsink & job is finished with joy expression on my friends face.
This article was prepared for you by Yogesh Panchal who works as a Computer Hardware Engineer in Mumbai India.
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Note: You can check his previous repair articles on CANON LBP2900 Laser Printer Unit Error
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Waleed Rishmawi
May 18, 2024 at 5:13 pm
replacing the whole board is the best way to go. I have seen this problem before in my shop and to replace the individual burnt LED is hard to do simply because all the led's are sitting on a heat sink plate and alot of heat needed to take them off baord. thanks for sharing and have a blessed day
Yogesh Panchal
May 18, 2024 at 5:35 pm
Right! Waleed
Parasuraman S
May 18, 2024 at 5:15 pm
Well done! Thanks for sharing!
Yogesh Panchal
May 18, 2024 at 5:36 pm
Thank You!sir
Albert van Bemmelen
May 18, 2024 at 6:17 pm
Didn't know these DOB pcb's can be bought? Changing 2835 LED warm-white 2.8mm x 3.5mm is hard to do anyway and so this was the best option to fix the problem.
Anwar Yunas Shiekh
May 18, 2024 at 10:00 pm
Supposedly the new generation of LED mains bulbs will be significantly more efficient; I wonder how that is achieved.
Yogesh Panchal
May 19, 2024 at 10:30 pm
Anwar Yunas Shiekh
You are right newer LED Bulbs are long lasting than Earlier.
Yogesh Panchal
May 18, 2024 at 11:40 pm
Thanks!Albert
Imoudu.O
May 19, 2024 at 2:37 am
I don't know that part is available to buy, is it cheaper than buying a complete now lamp?Good job though.
Yogesh Panchal
May 19, 2024 at 10:35 pm
Imoudu.O
yes i revived his decorative device in less than 10% cost of its original cost.
Hollis LuQuette
May 20, 2024 at 1:46 am
I did not know those boards were available , I usually just change out the leds if I have that type .. I will try and look those up ... Over here at the Dollar stores I can buy a 4 pack of led light bulbs for 2-3 dollars , If those DOB boards are cheap I might buy some ..
Yogesh Panchal
May 21, 2024 at 3:11 pm
Hollis LuQuette,
Now a days LED Light Bulbs are very cheap, But it is thrill when you repair it your own.
Ulises Aguilar
June 7, 2024 at 11:41 am
nice job sir
Maurizio
June 10, 2024 at 5:21 am
Hi ppl,
I keep suspecting that some of these DOB LEB bulbs are purposely carrying more current than expected (mayb the driver R value is smaller). The pro is that the bulbs are lighter, the con is that those bulbs last much less. My personal experience is replacing the bulb every year of normal evening activity, comparable with an old W bulb! Is anybody out there who has already addressed that issue? thanks