How Did This PHILIPS LED TV Model 32PFL3305-V7 Survive A Bad Solder Of Cap For Last 12 Years?
This TV belonged to my elder brother’s classmate, staying in my town. He was referred to me by yet another classmate, who was very close to me from childhood days. He used to bring his Sharp two-in-one for belt changing occasionally and was also instrumental in bringing his brother’s set for repair long back. He reported that his TV, which was working perfectly fine for more than 12 years without ever opening it for service, developed some problems like presence of lines in the display and picture jumping with RGB. Following are extracts of the videos sent by him on my request to evaluate the extent of damage:
From the videos and explanation of the problems by the customer, I could gather that the video goes off before which some lines with or without RGB display appears. In order to have a look at the problems personally, I visited his home on my return from my hospital duty and confirmed the same. The problem was there even when the inputs were different like a USB, confirming that the causes were indeed hidden in the TV and not in the associated peripherals. The customer brought the TV to my home and kept it on the verandah as per my request. The second picture you see in the beginning of this article is after I opened the back cover and subjected it to a thorough cleaning.
As we all know, there were many possibilities and we need to check and eliminate the suspected sources in order to arrive at the real cause. I began from checking the voltages at the power supply. The voltages were present both in the power supply as well as in the panel such as VGL, VGH, AVDD, V.com and VCC. They too were very stable. I did not find any regulator ICs or associated parts getting hot. I checked and found that the blue screen remained stable until timed out, but starts jumping only when a video was fed; that too after a few minutes’ of operation. So, this indicated a problem in the video section, which could also be due to noisy power supply. I removed the power supply board and did a visual inspection. Believe me; I was surprised to see an electrolytic capacitor with one leg abnormally lifted in the primary hot section. When I checked it with my finger whether it was holding the connection, it just came off! The other side of the PCB showed that the leg had not gone through the hole and it was just remaining touched perhaps on a very thin solder! Let us have a look at this miraculous survival:
The yellow arrow indicates the portion, from where the leg came off from the other side on touching. Anyhow, this was a strange case and it could have caused unstable power supply. But if this was not making proper contact to pass on the required voltage/current, primary would have got shut down.
So, why was the PS board working might remain as yet another unresolved mystery. Anyhow, the PS board had enough dry solders and almost all the electrolytic capacitors were out of range. So, I replaced all of them and also did a thorough retouch of the board including the many tiny SMD components. After cleaning and ensuring that there were no man made mistakes like overlapping solders etc., the PS board was refit. Let us have a close look of the PS Board & Mother Board :
The flickering and video going off still persisted on testing the TV. Then I checked the electrolytic caps in the video section of the mother board. Found these to be dry. So, replaced all the electrolytic caps in the mother board too.
Since it was a double sided PCB, and the legs of the caps were soldered within a circle marked with white boarder on the other side, I took care not to overshoot the soldering area. I also checked and rechecked the solderings done using a X10 lens to make sure that no shorts were made by mistake. Then fit the MB back and checked. This time the video remained stable and the TV worked properly even after testing it for several hours continuously. So, it was a case of bad electrolytic capacitors and bad solders in the power supply too. Let us have a look of the crystal clear picture on this 12 year old TV using LCD backlight:
The speakers were found torn and I replaced both of them after taking consent from the customer. A new RC Unit was also purchased as the old one was found malfunctioning.
Informed the customer after ensuring that the TV worked satisfactorily for hours together and fixing the back cover.
Mission accomplished with satisfaction, which got qualified to get entry to the collection bag.
This article was prepared for you by Parasuraman Subramanian from India. He is 76 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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Mark J
May 23, 2026 at 9:39 am
Great job on the repair. Thank you again for sharing.
Parasuraman S
May 23, 2026 at 10:24 am
Many thanks for your comments, dear Mark!
Imoudu.O
May 23, 2026 at 8:38 pm
I wonder why you didn't suspect the panel having seen their is t-con
stable voltages,well I now know even ps can affect panel,thanks sir
Parasuraman S
May 24, 2026 at 7:56 am
Yes, primary suspect is always the power supply in almost all the cases. First duty of a technician as always is to check right from the mains cord to the output whenever any PS related problems are suspected. Many thanks for your comments, dear Imoudu!
Anthony Paterson
May 23, 2026 at 12:22 pm
Parasuraman,
You are the 'King of Electrolytic Capacitors'. Your many articles show that electrolytic capacitors have a limited life and are likely culprits for circuit malfunction.
Which brand of electrolytic capacitor do you use or recommend?
Jestine would not have a repair article without your continuous contributions.
Well done and thank you.
Parasuraman S
May 23, 2026 at 12:53 pm
Many thanks for your wonderful comments and encouragement! Jestine Yong is very kind to me and do accommodate me to the maximum extent possible, in spite of his busy schedule in his passion of teaching. I developed the flair for writing articles only because of his support, guidance and encouragement!
Normally I use Keltron capacitors which are locally made caps of international standards of best quality. But many times, size matters and I then use Samsung caps.
Albert van Bemmelen
May 23, 2026 at 2:53 pm
Sherlock will be proud again! The mystery to me however was still the part where you took care not to overshoot the soldering area?
Parasuraman S
May 23, 2026 at 7:21 pm
The marking done with white paint was to ensure that no arcing takes place as opposite polarity tracks go around it. What I meant was taking care not to exceed this limit marked when I resoldered the capacitor leg. Many thanks for your expert comments, dear Albert!
Narinder Singh
May 26, 2026 at 3:36 pm
Well done once again, really enjoyed reading your article. I admire and love your perceverance.
Parasuraman S
May 27, 2026 at 8:52 pm
Many thanks for your encouraging comments!
Yogesh Panchal
May 23, 2026 at 5:58 pm
Good Job!Sir
You are right—you cannot anticipate 'cold joints' in solder beforehand, and for this, you have to utilize certain innate senses bestowed upon humans by nature.
Parasuraman S
May 24, 2026 at 7:57 am
Many thanks for your comments, Yogesh Bai!
Imoudu.O
May 23, 2026 at 8:49 pm
Let me ask you some questions
1.When you deal with tv backlight problem and you need to use led driver module,and module uses 12V input to operate,from where do you tap the 12v to led driver?
2. If I tap 12V from main board or t-con board to led driver module, can it have any effect on the tv generally?
Parasuraman S
May 24, 2026 at 8:02 am
1. If the DC out of the PS Board, we can tap it. Else we need to use a DC to DC booster board. Sometimes the current drawn by the LED driver used might draw more current causing the TV to malfunction. In that case, we need to provide a 12V supply separately.
2. As a general principle, we should not draw it from the secondary supplies. We should try to draw it as a separate connection from the 12V source in the PS Board.
Many thanks for your valid questions!
George P
May 23, 2026 at 11:07 pm
I a perfect world we would have e-caps that were perfectly sealed and never dried out, solder that was heat resistant and not able to crystalize and caps that never changed value. However I suspect that that level of manufacturing would make components so costly that most would not be able to afford the devices. So we suffer with lower levels of quality. And make friends here on Jestine Yong's site enriching our lives. Great job Parasuraman. King of dry solders and e-caps, for making our reading so enjoyable!
Parasuraman S
May 24, 2026 at 8:06 am
Reading can be made enjoyable by anyone who has developed a flair for writing. But the real joy comes from when we enjoy our works and reach a successful result. Jestine Yong is a very generous person who allow birds of the same feather flock together in this forum! Let our tribe increase by his unstinted efforts to roll out technicians from his world class training factory! Many thanks for your comments!
Cary Passik
May 24, 2026 at 12:02 am
How wonderful of you to share your knowledge. I enjoy seeing how it is possible to fix things for a few dollars in parts if you're an expert. Here in America, with the high cost of a skilled technician's labor, these items would just be tossed in a landfill. Unfortunately, the new replacement item may not last as long as the older repaired one!
Parasuraman S
May 24, 2026 at 8:11 am
Yes, I am fully aware of the situation described by you. The modern men do not appreciate or rather has time to even think about the efforts that might have gone in before a produce reaches their hands. It is nothing but sheer abuse that we throw away such devices and go for a new one. I feel the respective Governments should pay some incentive to those who are involved in e-waste control such as us. That would make it cheaper for technicians to render services and the sad situation can be reversed.
Many thanks for your involved comments!
Philip
May 24, 2026 at 4:06 pm
Thank you for the great effort. Its uncommon to find smd components right beneath the "primary hot section" or "the other side of the PCB" (your words). Its rare even on a double sided PCB. Its just as rare for most technicians to give detailed replies as you do, self-sacrifice is almost non-existant. Please brother, do take good care of our sister-in-law. Be strong. Always do find time to give her company and help whenever necessary. Keep her mind engaged by frequently talking to her, she needs you now more than ever before (this concerns what you wrote elsewhere).
Parasuraman S
May 24, 2026 at 9:08 pm
Many thanks for your touching comments, dear Philip! I am glad to have found another brother, living in another part of the globe, yet very close to hearts! Shall take good care of her and there is no compromise on that!