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

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

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

LED TV power off
 

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.
Brian

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wrote in message
...
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

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

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

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 105CÂ* (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

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.

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 105CÂ* (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."

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.

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.