No Picture Problem In VIDEOCON V3218 Resolved
This LED TV belonged to my colleague in the hospital and was brought to me with the complaint that the display failed while watching. As this TV had visited me earlier for a panel change, I am skipping preliminary images; please see: https://jestineyong.com/futile-attempts-to-resolve-double-image-in-videocon-led-tv-v3218-resulted-in-panel-replacement/
On opening and inspection, I found that a capacitor in the inverter section had burst and the power supply indeed had suffered a surge. The Mosfet driving the LED was also found short. The TV was having an external inverter board as its original inverter section had failed a few months back. As the work was handled by my friend who replaced the panel, I do not have a track of it.
After replacing the caps in the power supply section, I fetched a replacement board and fixed a better Mosfet rated for 11A 800V and also replaced the caps in the board, as suggested by my techie friends. The input to the board was given from the primary of the inverter section and the output was fed to the LED driving section, after removing its optocoupler. This universal inverter board is very cheap and available freely in the market for such bypass work.
After replacing the board, when I applied power, the display was back. I applied a video in and found it to be working very well. I tested it for several hours before giving delivery. Mission accomplished that enabled satisfaction getting added to its collection.
This article was prepared for you by Parasuraman Subramanian from India. He is 74 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
July 5, 2024 at 6:48 pm
Good job of course but sadly it is unclear what universal inverter board exactly was used, that is very cheap and available freely in the market?
Parasuraman S
July 5, 2024 at 8:43 pm
I have covered the use of that board a few times before. It is generally available in the market. Chinese make. Please zoom the centre picture at the last row. Thanks for your keen observaton and expert comments!
Albert van Bemmelen
July 6, 2024 at 4:46 am
I'm afraid dear Parasuraman that likely often those boards are available in India and not for sale in other countries. Previously that was the case when I tried to find such a universal TV board you had used in a repair.
And not knowing what the here not mentioned board model was makes it even harder to be sure it is available for us too.
Parasuraman S
July 6, 2024 at 6:15 pm
I could get following links which would give you an idea of this board: https://www.lazada.com.ph/products/4-wire-power-supply-board-for-led-tv-5-24volts-i2756994885.html
https://articulo.mercadolibre.com.mx/MLM-744795348-modulo-universal-variable-para-reparar-fuentes-de-pantallas-_JM
Hope this helps!
Justice
July 6, 2024 at 4:12 am
Graet work and informative, thank Parasuraman.
Parasuraman S
July 6, 2024 at 6:06 pm
Many thanks!
Philip
July 7, 2024 at 9:37 am
Thanks Parasuraman for your ever wonderful articles. Thanks Albert. Parasuraman, some universal power modules have 3 connection cables while others have 5. Which one would you recommend I use for a dead 14 inch Sharp CRT TV, a Samsung 21 CRT and a Zec 14 CRT. Chinese CRT TVs are much easier to work on than say a 25 inch CRT ToshibaTV that gave me a hard time to repair with rare power capacitors and a hard to find D2539 power transistor, all parts were salvaged. It also had a power circuit with a seemingly misplaced resistor (not rated) instead of a diode as indicated on the board, now that is very confussing. Thanks Parasuraman, Jestine Yong, Humphrey Kimathi, and all the rest for your help. I'm a villager who loves CRT TV repair and wonderful coloured images.
Parasuraman S
July 7, 2024 at 7:13 pm
Many thanks for your wonderful comments! Very unique indeed! Glad to hear about your CRT repairs! Just keep going, all the very best! The three wire Universal Module (Red, Green and Black) would do for the CRT. Just leave the green unconnected, tie and cover it up with a tape so that it does not make contact with any other components on the board.
Yogesh Panchal
July 8, 2024 at 2:04 pm
Good Job! Sir
These external modules are very handy for use,Sometimes one has to struggle for parts despite finding the fault.
Parasuraman S
July 8, 2024 at 9:31 pm
Yes, you are right! Thanks for your comments!
Yogesh Panchal
July 8, 2024 at 2:10 pm
Albert,
These Modules are easily available in India, & are depends on what
wattage SMPS you are working on.
CA888 STR 5 wire Module & 5L0380R SMPS PWM Module are popular.
for LED/LCD TV different types of Module Used By the size of screen.
Parasuraman S
July 8, 2024 at 9:31 pm
Thanks for the inputs, Yogesh Bhai!
Waleed Rishmawi
July 9, 2024 at 11:53 pm
This brand model number is not available in my country and I am sure the replacement boards are not either. Any way, good repair my friend and thanks for sharing. Have a blessed day
Parasuraman S
July 10, 2024 at 8:43 pm
Many thanks, dear friend!
Tito Kanshulu
July 15, 2024 at 5:31 pm
Good job Sir