Samsung Laptop Adaptor AP04214-UV Saved From Dump
This ACA was brought by one of my colleagues in the hospital with the complaint that there were power surges and interruptions after which it became dead. I opened the ACA and checked. The tank capacitor (4.7uF/400V) was bulged.
The low value current rush protector resistor in the source of the Mosfet was found burst. The Mosfet was found short on checking. The Bridge Rectifier was short. The 3.15A glass fuse had burst.
I replaced all these components along with the rest of all electrolytic capacitors as the readings were not good. Then did a thorough retouch of the board, cleaned it thoroughly and applied power. There was no output. I checked pin 7 (VCC) of 3842, a fixed frequency current mode controller, and found that it was zero. I removed the IC and checked and found that the DC voltage was present. It meant that the IC was loading. So, my natural doubt was on the IC itself.
I provided an 8 PIN IC socket and put a new 3842 in it and applied power, upon which the output was ok. I tested it for a few minutes before putting the cover back and fixing it with black tapes, camouflaging it with the cover, which was also black. Mission accomplished with merriment as I could satisfy one of my colleagues in the hospital. Satisfaction of a different kind, this time, found its source and coolly entered there!
P.S. The voltage of 22.85 against 19V of ACA was because of ‘no load’ condition. It will be ok when connected to the Laptop.
This was confirmed by the user later, as he himself was a bio-technician.
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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You may check on his previous article on POWER INTERRUPTIONS CAUSED SOFTWARE CORRUPTION IN HAIER LED TV LE22B600
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Waleed Rishmawi
August 3, 2024 at 9:27 pm
Great work my dear friend. Have a blessed day
Parasuraman S
August 3, 2024 at 10:54 pm
Many thanks dear friend!
Tayo
August 3, 2024 at 10:15 pm
Excellent save Maestro. Im rarely able to save these AC adapters from the dump. For me, when they fail, they fail spectacularly with multiple hard to find components taking a hit....just like this one you resurrected. I usually harvest what remains for my parts bin. Quality laptoo AC adapters are common and cheap in my area. Although the case can be made for saving high wattage adapters as they are less common and thus more valuable. Thank you again for sharing this. I will remember your steps next time i take one on.
Parasuraman S
August 4, 2024 at 10:02 am
Very nice of you to shower appreciations and encouraging me! Many thanks, dear!
Andy Shiekh
August 3, 2024 at 10:46 pm
Another fine fix
Parasuraman S
August 4, 2024 at 10:02 am
Thanks!
Yogesh Panchal
August 3, 2024 at 11:21 pm
Good Fix! Sir
Parasuraman S
August 4, 2024 at 10:03 am
Thanks, dear Yogesh!
Albert van Bemmelen
August 3, 2024 at 11:46 pm
Never heard ACA before? You mean AC Adapter (lol).
It was a lot of work to almost replace every component of the adapter to get it back running again.
Parasuraman S
August 4, 2024 at 10:04 am
HA! HA! Thanks! The adaptor belonged to a friend of the customer, from whom he borrowed the laptop and he had no other choice!
Mark J
August 4, 2024 at 2:26 am
Parasuraman Subramanian Well done.
Parasuraman S
August 4, 2024 at 10:05 am
Many thanks, dear Mark!
NATARAJAN
August 4, 2024 at 12:51 pm
Sir with respects I appreciate your detailed article. Thanks for sharing
your experience.
Parasuraman S
August 4, 2024 at 9:07 pm
Thanks dear!
Humberto
August 19, 2024 at 11:46 pm
Other device saved from the dump. I really enjoyed reading your article. Congratulations.