TV not powering on - with standby red –led flashing

[nomoresonys]

Re: TV not powering on - with standby red –led flashing

Test c18-19 and 20 as described in post #55.

[Willem01]

Re: TV not powering on - with standby red –led flashing

Test c18-19 and 20 as described in post #55.

They all start from sbout from 2.9ohm and rise then until the meter shows a 1 or l

[nomoresonys]

Re: TV not powering on - with standby red –led flashing

And the other non-suspect caps do the same when tested? The rise should be even and steady.

[nomoresonys]

Re: TV not powering on - with standby red –led flashing

It can be tricky tracking down bad caps, it doesn't take much being out of specs to cause a problem, here's NorCal tracking some down:

https://www.youtube.com/watch?v=3S-3J-FySzc

[Willem01]

Re: TV not powering on - with standby red –led flashing

And the other non-suspect caps do the same when tested? The rise should be even and steady.

Found C16 to be doing nothing

Edit... I set the meter to 2000k and then it show a steady increase,, so all the caps are good

[nomoresonys]

Re: TV not powering on - with standby red –led flashing

Well that's just a "dirty test", like I said a partial test you can try when you don't have the meters needed, to test them completely you need a meter or meters that can test capacitance and esr, the 10-20 dollar combo meters, there's a bunch on ebay, seem to be pretty accurate.

[Willem01]

Re: TV not powering on - with standby red –led flashing

Ok so a recap on the existing issue:
power cord plugged in for ever the standby led give a solid status - the tv switch on.
Power cord unplugged for 40sec, plug it back in flashing led status - does not switch on only if I heatup C18, C19, C20 led status change to solid and it powers on.
Have replaced all caps, done the 'dirty cap test' as per nomoresonys suggested, as I have not an ESR meter think the caps must be all good as they are new..
Ai seems as IF I need to throw in the towel but dont want to

[dick_barton]

Re: TV not powering on - with standby red –led flashing

On L1 it fluctuates 3.6 - 4.7 with the standby led flashing
When I unplug the CON3 plug for 10 sec plug it back the led stops flashing amd turn solid, then the volt on L1 is about 22v
D9 cathode voltage fluctuates from 21v - 60v that is without any pins jumped

D9 cathode is connected to L1 so the voltages should be the same.

I think that there is still aproblem with the standby circuit centered around U1 and Q4

Did you check D10 out of circuit.
R30 is 100 ohm and can you confirm that.
What value zener did you use to replace ZD3 which your schematic says is 18V

[Willem01]

Re: TV not powering on - with standby red –led flashing

D9 cathode is connected to L1 so the voltages should be the same.

I think that there is still aproblem with the standby circuit centered around U1 and Q4

Did you check D10 out of circuit.
R30 is 100 ohm and can you confirm that.
What value zener did you use to replace ZD3 which your schematic says is 18V

D9 to L1 - voltages are the same
R30-yes that is at 100ohm
Zener diode as in pic... Replaced it with a 18v one
D10 - help on this one, how do I measure {same as for any other diode} if so with the probes on the one way and then swapped the other way it does not matter what side I get one reading both ways 098 on multimeter

[vinceroger69]

Re: TV not powering on - with standby red –led flashing

is d10 removed from the circuit it should only measure in one direction

[dick_barton]

Re: TV not powering on - with standby red –led flashing

In an earlier post this is what you gave

There is no reading for the 3.3v
C1 and C2 reads 315v for pinned and not pinned
Ohm readings for
ZD3... 00.4ohm
D10..25ohm
R26..00.5ohm
R28..510ohm(meter set to 2000ohm)
R29..18.7ohm
R30..25.1ohm
R31..00.7ohm

D10 is across 100 ohm resistor so should have read 100 ohms.
The only way to check is to lift D10 and put your meter in diode mode. You should have a reading one way eg 0.75 and no reading when you swap your meter leads over.
Then you can check that R30 does read 100 ohms

[Willem01]

Re: TV not powering on - with standby red –led flashing

Agh sorry D10 is still in circuite,, will remove and give feedback again

[Willem01]

Re: TV not powering on - with standby red –led flashing

D10 is lifted it gives me a reading only in one way on the diode test
When testing for resistance it gives 2.69ohms only in one direction
R30 gives me 98.6ohm

[dick_barton]

Re: TV not powering on - with standby red –led flashing

2.69 ohms or 2.69 Kohms or 2.69 Mohms?

[Willem01]

Re: TV not powering on - with standby red –led flashing

2.69 ohms or 2.69 Kohms or 2.69 Mohms?

The multimeter is set like in the non illuminated display, sorry but I got another meter and is not confident in using it and feel silly

Added the wrong image before this is now correct

[dick_barton]

Re: TV not powering on - with standby red –led flashing

it's 2.69 Mohms, the range indicater is at the bottom MΩ

[Willem01]

Re: TV not powering on - with standby red –led flashing

it's 2.69 Mohms, the range indicater is at the bottom MΩ

Do I have to replace it, if so can I use the one as per attatchment

[nomoresonys]

Re: TV not powering on - with standby red –led flashing

If it's still out of circuit, check it in diode mode.

[Willem01]

Re: TV not powering on - with standby red –led flashing

If it's still out of circuit, check it in diode mode.

It give a reading only in one direction

[nomoresonys]

Re: TV not powering on - with standby red –led flashing

That's what you want from a good diode.