Saving Computer SMPS Part – 13
Continuing my efforts to bring back the defective ATX Power Supplies which are replaced with new by most of the people globally! Following two such SMPS (written off cases, to tell the truth) were brought back to working conditions:
Case (1) iBall LPE223-400 :
The complaint on this SMPS which was serviced by me in 2015 was it did not take load. It was given to me after cleaning the inside by the IT Administrator of the Hospital, where I work, which saved my time and efforts. I looked through my records and noticed that except the tank capacitors all other caps were replaced during the last service and there were no dry solder and it remained firm since I had retouched all the points last time.
Just see how a good soldering work carried out lasts and lasts for years! I removed the tank capacitors and checked and was not surprised to see the readings:
470uF/200V caps were reading as 292uF! Replaced these two caps and applied power with tester and load and found it to be working very well. 12V/25W bulb was given as load.
Case (2) Intex Classic : The complaint reported was that it was getting heated up and fan was not running. This also was cleaned very well saving my time. I opened the cover and saw a few caps bulgy in the secondary section. This is the first time this sturdy SMPS has come for service and when I looked at the board, it had a good amount of varnish coat on the solder side.
A few joints looked strained due to heat, wear and tear, which was quite normal on an age old SMPS, which worked continuously for years together. Let us have a look at the related pictures before we proceed further:
The tank caps were reading almost half of its values! So, replaced all the electrolytic caps on the board and used my mini cordless grinder (Relife Model RL-068B) to remove the varnish coating on the solder joints. Then applied fresh solder, checked for any man-made shorts, which were there very much and rectified the wrong doings too!
Then cleaned the board thoroughly and applied power to gladly see that it worked very well:
Double missions accomplished with double satisfactions getting collected to the bag!
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
March 15, 2025 at 5:47 pm
Always nice to read about fixing those older used smps units!
Parasuraman S
March 15, 2025 at 8:37 pm
Yes, it is always intriguing to fix these SMPS boards and make them work again! Thanks, dear Albert!
Waleed Rishmawi
March 15, 2025 at 8:36 pm
Seems like these power supplies have always the same faults, bad capacitors and dry joints, I have not seen anything else wrong with them, is a manufacturer issue. Have a blessed day
Parasuraman S
March 15, 2025 at 10:42 pm
Looks like these are designed to fail after a period. Anyhow, the kind of work we do to revive it makes it function for many years, which the manufacturers might not have guessed.
Anwar Yunas Shiekh
March 15, 2025 at 9:59 pm
I'm used to secondary capacitors failing but am surprised so many primary capacitors are failing. I am assuming these supplies don't use APFC
Parasuraman S
March 15, 2025 at 10:44 pm
Suppliers would always compromise quality for cost because of neck to neck competition and this is the net result. Anyhow we are all there to save the device from a dump! Thanks for your comments!
YOGESH PANCHAL
March 16, 2025 at 12:36 am
Good Job! Sir
Does Relife Model RL-068B able to make a groove on screw head?
Parasuraman S
March 16, 2025 at 10:27 am
I have not yet tried it that way, Yogesh Bai! Many thanks!
Mark J
March 16, 2025 at 2:40 am
Parasuraman good job on the repair. I always enjoy your ATX power supply repair articles.
Parasuraman S
March 16, 2025 at 10:28 am
Many thanks for your very valuable comments and support, dear Mark!