Dead Computer (Locally Assembled) Brought Back To Life
This locally assembled computer was brought to me dead by a customer whose monitor was serviced and given in 2023. The complaint was that when his wife switched on the computer, she heard a loud noise and it went dead.
I opened the side cover and looked inside for any visible damages or unauthorized entry of ‘nocturnal visitors’ and could not find any:
I applied power and did not find any change and the on/off switch operation from the front cabinet did not show any indication of getting on. I suspected that the power cord was defective and it indeed was open when I checked with my Multimeter. Since the customer reported hearing of a sound, I used a new power cord and applied power through a 100W series bulb as a precaution. I noticed that the bulb was in full glow indicating that the SMPS was definitely having some problems.
So, disconnected the power and removed all the secondary connections of the SMPS and took it out from the cabinet by unscrewing five screws that held it in place. Opened and checked and found that the fuse and NTC were ok, but the DC side showed dead short. Further tests showed that two 13007 transistors and two of the RL207 diodes were short. I replaced the two transistors and all four diodes and did a thorough retouch of the board. ESR of all caps and the values of main caps were also ok when checked at random.
Then applied power with a 12V, 25W bulb as a load and connected my SMPS tester. The output was good and the SMPS fan also whirred smoothly. Then fixed its cover and assembled it back to the computer. Then reconnected all connectors as how it was before. Then applied power and found that the computer was getting on. I had a monitor which was ready after repair. I connected the computer to it and also connected a spare USB type keyboard and fixed a wireless mouse which I had in my laptop.
The computer was working superfine bringing relief to me as any software related problem could have taken more of my time and I was not equipped to handle software issues of a computer. Let us have a look at the progressive results:
Mission accomplished in record time earning great satisfaction that found its way to join its predecessors!
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
April 19, 2025 at 7:40 pm
I am quite sure that you are able and qualified to handle and solve any software related issues of any computer too dear Parasuraman!
All it probably takes is having enough backup tools and the right programs at hand on cd, dvd, bluray or even as bootable iso on usb memory stick to help you out when needed. I already burned many dvd and BluRay discs to collect the tools I need.
Good idea is to use a program like Ashampoo Burning Studio 24 to burn found tools and also tv program recordings to DVD or BluRay. And I find Acronis 2024 to be a very valuable and safe and secure Backup program to make an image copy of my computer's C:/ ssd boot hdd (All it takes in case my computer crashes is this boot disc and only about 7 to 8 minutes of RESTORE and it gets my image back from my external made Windows backup to my C:/ drive without any problem whatsoever!).
And I also use the superfine Tenorshare 4DDig Recovery program that in my and many other users opinion is the best program to recover any lost file on hdd or other media where other programs simply fail! It even works on harddisks that are formatted in other formats like in Linux boot format. It even helped me already several times to recover a tv recording from my 2.5 inch internal hdd in my satellite receiver that got deleted or accidentally crashed where I previously was unable to save and see it. It found my over 9 GB large video recording of the Eurovision Songfestival in seconds and restored and saved it in only minutes! Why I bought this program complete with unlimited lifetime upgrade support for about 97 euro including VAT online last year!
Parasuraman S
April 19, 2025 at 9:08 pm
Thanks to you, dear Albert for your very valuable comments and suggestions. I am sure many readers would also be beneficial due to this! Somehow, I have put a border on my service work and would prefer to be within that. I have done computer programming once during my employment with BPL and am aware of the logics behind it. I used to trouble shoot, reinstall programs during those days. But now technology has leaped far ahead and I have disinclination in pursuing this field.
Anwar Yunas Shiekh
April 19, 2025 at 8:37 pm
unauthorized entry of ‘nocturnal visitors’
nicely put
Parasuraman S
April 19, 2025 at 10:24 pm
Thanks for your keen observation and appreciation!
Yogesh Panchal
April 19, 2025 at 11:00 pm
Good Job! Sir,
Hard Disk Dive Bad sector related & Software related problems are time Consuming & people expected that work as complimentary.most of the time people are not ready to pay for extra work for software troubleshooting,they not understand value for their DATA until it destroyed because of Bad HDD or corrupted software.
Parasuraman S
April 20, 2025 at 6:57 am
Very true! The general tendency is to expect the best service but pay as little as possible or sometimes nothing! What to do!
Waleed Rishmawi
April 20, 2025 at 12:40 am
Very interesting repair. I never bother with desk top power supplies repair for they are very cheap to buy now a days. I just replace with a working one . Thanks for sharing, have a blessed day
Parasuraman S
April 20, 2025 at 6:58 am
Yes, true. But it won't last long and might fail soon, unless you retouch the board before giving it.
Mark J
April 20, 2025 at 3:11 am
Parasuraman another great power supply repair. Thank you for sharing.
Parasuraman S
April 20, 2025 at 6:58 am
Many thanks, dear Mark!