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UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
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#1
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LED TV power off
One of our TVs is a 32 inch Samsung, which has an excellent picture.
2 years ago the power board blew so i replaced it with a secondhand board, which was an easy job. Now it's powering up but then powering off after about 5 minutes and not even going into standby. Unplugging the power lead and waiting a bit and then restarting brings it back to life but then it powers off again. Before I buy another board is it: - likely to be the power board - are there suspect components on the board (I'm guessing capacitors) that are worth replacing (I know how to solder them in). thx |
#2
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LED TV power off
On Sunday, 9 February 2020 19:53:36 UTC, John Smith wrote:
One of our TVs is a 32 inch Samsung, which has an excellent picture. 2 years ago the power board blew so i replaced it with a secondhand board, which was an easy job. Now it's powering up but then powering off after about 5 minutes and not even going into standby. Unplugging the power lead and waiting a bit and then restarting brings it back to life but then it powers off again. Before I buy another board is it: - likely to be the power board - are there suspect components on the board (I'm guessing capacitors) that are worth replacing (I know how to solder them in). thx hard to know, but certainly failing caps are a common cause. One of those cheap chinese component testers is good for testing caps - the caps need removing to check them though. NT |
#3
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LED TV power off
On 09/02/2020 19:53, John Smith wrote:
One of our TVs is a 32 inch Samsung, which has an excellent picture. 2 years ago the power board blew so i replaced it with a secondhand board, which was an easy job. Now it's powering up but then powering off after about 5 minutes and not even going into standby. Unplugging the power lead and waiting a bit and then restarting brings it back to life but then it powers off again. Before I buy another board is it: - likely to be the power board - are there suspect components on the board (I'm guessing capacitors) that are worth replacing (I know how to solder them in). thx Dunno. I had a brand new telly wot done this. Took it back and got another -- "Anyone who believes that the laws of physics are mere social conventions is invited to try transgressing those conventions from the windows of my apartment. (I live on the twenty-first floor.) " Alan Sokal |
#5
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LED TV power off
Yes switch mode psus can actually damage the semiconductors in the bit
which is live to mains due to a mains spike, in which case it just is dead, but the one he has sounds more hopeful. Its probably quite old now though so he may or may not be lucky. Somebody in the old days would have been knowledgeable on such things, but these days particularly with the smaller sizes people tend to just dump them and buy a new one, sadly. Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "The Natural Philosopher" wrote in message ... On 09/02/2020 19:53, John Smith wrote: One of our TVs is a 32 inch Samsung, which has an excellent picture. 2 years ago the power board blew so i replaced it with a secondhand board, which was an easy job. Now it's powering up but then powering off after about 5 minutes and not even going into standby. Unplugging the power lead and waiting a bit and then restarting brings it back to life but then it powers off again. Before I buy another board is it: - likely to be the power board - are there suspect components on the board (I'm guessing capacitors) that are worth replacing (I know how to solder them in). thx Dunno. I had a brand new telly wot done this. Took it back and got another -- "Anyone who believes that the laws of physics are mere social conventions is invited to try transgressing those conventions from the windows of my apartment. (I live on the twenty-first floor.) " Alan Sokal |
#6
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LED TV power off
On 10/02/2020 07:29, Brian Gaff (Sofa 2) wrote:
Yes when you say the original blew, exactly how did it blow? The reason I ask is that the behaviour you describe could just be a protection circuit doing tis job if something has caused a short somewhere. As has been said, you can try the capacitors. Samsung went through a phase a few years back when this seemingly was an issue. I had to replace two obviously blown capacitors in my Samsung TV purchased in 2009, however they did last around 8 years. The outward symptom was that the TV would not switch on reliably. I have a remote controlled mains plug and remove the mains from the TV and other under TV equipment each night after watching. On my TV a LED flashes during the power on sequence. This failed to flash occasionally when mains was re-applied. Cycling the mains on/off would allow a subsequent TV power on sequence to be successfully completed. Over a period of a month or so the times when the TV would not switch on became more frequent and sometimes more than one mains on/of cycle was required. The two capacitors were in the power supply and had been positioned 1 mm away from a heat-sink. The top of both capacitors had bulged (domed). The TV had a fan and although not providing an air flow to the power supply it had attracted all the dust in the world and required removing and cleaning. To the OP. When replacing the capacitors buy replacements that are described as low ESR or low Z and are rated for 105C (105 degrees Centigrade) rather than anything rated at 85C. -- mailto : news {at} admac {dot} myzen {dot} co {dot} uk |
#7
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LED TV power off
On 10/02/2020 08:48, alan_m wrote:
To the OP. When replacing the capacitors buy replacements that are described as low ESR or low Z and are rated for 105CĀ* (105 degrees Centigrade) rather than anything rated at 85C. Examples From Rapid Electonics https://www.rapidonline.com/panasoni...0-105-c-565389 or https://tinyurl.com/vgfo8c4 From CPC, Panasonic FM or FR range of capacitors. https://cpc.farnell.com/w/c/electron...onic%20low%20z or https://tinyurl.com/w98p82q https://cpc.farnell.com/w/c/electron...onic%20low%20z or https://tinyurl.com/wz7hbbe -- mailto : news {at} admac {dot} myzen {dot} co {dot} uk |
#8
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LED TV power off
On 2020-02-10 09:17:58 +0000, alan_m said:
On 10/02/2020 08:48, alan_m wrote: To the OP. When replacing the capacitors buy replacements that are described as low ESR or low Z and are rated for 105C* (105 degrees Centigrade) rather than anything rated at 85C. Examples... Many thanks - will get the board out later and give it a good inspection. I'm a firm supporter of fixing things rather than chucking them. |
#9
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LED TV power off
On 10/02/2020 11:34, John Smith wrote:
On 2020-02-10 09:17:58 +0000, alan_m said: On 10/02/2020 08:48, alan_m wrote: To the OP. When replacing the capacitors buy replacements that are described as low ESR or low Z and are rated for 105CĀ* (105 degrees Centigrade) rather than anything rated at 85C. Examples... Many thanks - will get the board out later and give it a good inspection. I'm a firm supporter of fixing things rather than chucking them. replace all 'lectros as a matter of course -- "What do you think about Gay Marriage?" "I don't." "Don't what?" "Think about Gay Marriage." |
#10
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LED TV power off
In article 2020020919533269548-nospam@nospamcom,
John Smith wrote: One of our TVs is a 32 inch Samsung, which has an excellent picture. That'll be a first, then. ;-) 2 years ago the power board blew so i replaced it with a secondhand board, which was an easy job. As did mine. Just outside warranty. Won't be buying another. -- *For every action, there is an equal and opposite criticism * Dave Plowman London SW To e-mail, change noise into sound. |
#11
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LED TV power off
In article ,
The Natural Philosopher wrote: On 10/02/2020 11:34, John Smith wrote: On 2020-02-10 09:17:58 +0000, alan_m said: On 10/02/2020 08:48, alan_m wrote: To the OP. When replacing the capacitors buy replacements that are described as low ESR or low Z and are rated for 105C (105 degrees Centigrade) rather than anything rated at 85C. Examples... Many thanks - will get the board out later and give it a good inspection. I'm a firm supporter of fixing things rather than chucking them. replace all 'lectros as a matter of course Not got an ESR meter, then? - -- *I pretend to work. - they pretend to pay me. Dave Plowman London SW To e-mail, change noise into sound. |
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