baird 42 flickering strobing wont start up

[notallbad]

Re: baird 42 flickering strobing wont start up

No probs, check the last couple of Posts

OK, no inverter connected, same voltage, but noise?

[wreksta]

Re: baird 42 flickering strobing wont start up

mate do you think it could be one of the caps under the heatsink would this cause the problem

on a side not mate if was all connected I get the spike noise when the lights start to strobe this is intime with the clicking surge noise if inverter disconnected I still get same nois just no flashing do you know what I mean now so something stopping correct voltages going to all 3 connectors on psu

[wreksta]

Re: baird 42 flickering strobing wont start up

No probs, check the last couple of Posts

OK, no inverter connected, same voltage, but noise?

yes still get that surging buzz noise

[notallbad]

Re: baird 42 flickering strobing wont start up

One wire connects to outer shell of bulb 1, then join the end connection of bulb 1 to the outer shell of bulb 2, then connect another wire to the end connection of bulb 2. You will then have two wire ends.

One connects to 24v the other to gnd, on the inverter connector on the PS b/d with the connector disconnected from the inverter.

Budm has a guide for doing this somewhere on here.

[notallbad]

Re: baird 42 flickering strobing wont start up

yes still get that surging buzz noise

OK, check the 24v inverter output as above with car bulbs, they should glow nice and bright steadily.

[wreksta]

Re: baird 42 flickering strobing wont start up

mate I don't understand the bulbs fire they just strobe the problem is with psu as I still get the surging without inverter connected

im going to change those caps

all im saying is there never enough voltage carried to the psu av 'inverter'auido connectors the spike surge fluxiates the voltage from low to high when I stop hearing the spiking noise the voltage drop way below to 00.2 etc

[notallbad]

Re: baird 42 flickering strobing wont start up

Changing all the caps is never a bad idea and may solve your issue, quick, cheap and easy to replace.

I see where your coming from, its not only the 24v inverter but also the audio 24v and main b/d volts which would most likely indicate the PS b/d but you had a steady volt reading on the filter cap powered up with no loads connected, so by connecting a load to the inverter output would eliminate a bad inverter or 24v inverter rail possibly.

[notallbad]

Re: baird 42 flickering strobing wont start up

You could with a resistor force the inverter board on to light up the backlights without the main b/d connected too.

Aha , just read your Post #102

[notallbad]

Re: baird 42 flickering strobing wont start up

I think the problem is further back than from those caps, refer back to Toms posts, doesnt seem to be the PFC circuitry but regulation.

[wreksta]

Re: baird 42 flickering strobing wont start up

any other ideas before removing these caps is there any way to test them with a esr meter the noise the psu makes sound like its coming from 1 of the transformers on the left of the psu theres 2 at same location how to determine that

[notallbad]

Re: baird 42 flickering strobing wont start up

An ESR meter is certainly an invaluable tool, they can be used in-circuit (No power to the board) with experience however most caps will need to be removed to test conclusively so having removed them you may as well replace. A DMM can be used to check whether a cap is short cct or not, when a cap completely fails it is most likely short cct as opposed to open cct like a resistor totally failing. But then this does not help if it is only partially failing.

An audio clip of the noise your getting may help.

Usually xformers/inductors making a noise is created by other factors causing it, not necessarily the xformer itself, so I have found out. i.e diodes, xsistors etc

This is with NO POWER going to the board!!!
You could check the diodes, DMM has a line with an arrow through it, at the bottom to the right on yours. With probes one way the DMM should give no reading, connected the other way around you should get a reading which varies depending on the type of diode under test. But as long as you do not get a reading at all in one direction is a good sign. The actual reading that you do get is not in fact meaningful just an indication. You can do this in-circuit but remember if theres a short on the circuit it may not necessarily be the diode but another component in the same part of the cct so you'd have to remove one leg of the diode and test again.

[wreksta]

Re: baird 42 flickering strobing wont start up

An ESR meter is certainly an invaluable tool, they can be used in-circuit (No power to the board) with experience however most caps will need to be removed to test conclusively so having removed them you may as well replace. A DMM can be used to check whether a cap is short cct or not, when a cap completely fails it is most likely short cct as opposed to open cct like a resistor totally failing. But then this does not help if it is only partially failing.

An audio clip of the noise your getting may help.

Usually xformers/inductors making a noise is created by other factors causing it, not necessarily the xformer itself, so I have found out. i.e diodes, xsistors etc

This is with NO POWER going to the board!!!
You could check the diodes, DMM has a line with an arrow through it, at the bottom to the right on yours. With probes one way the DMM should give no reading, connected the other way around you should get a reading which varies depending on the type of diode under test. But as long as you do not get a reading at all in one direction is a good sign. The actual reading that you do get is not in fact meaningful just an indication. You can do this in-circuit but remember if theres a short on the circuit it may not necessarily be the diode but another component in the same part of the cct so you'd have to remove one leg of the diode and test again.

doing this give me no reading at all if I put my mm on 60vdc I was getting 1558 or 15.8 any other ideas

[notallbad]

Re: baird 42 flickering strobing wont start up

There should NOT be mains power connected - just to be sure.

Across caps or diodes?

Dmm should be on ohm range for caps and diode setting for urm diodes.

However, with the dmm set to a volt range and probes across a cap you should see the dmm read a voltage that gradually decreases and on an ohm setting see the resistance gradually increase.
Try it with a cap out of circuit to see what happens but don't use a large cap which is 'charged', could damage your Dmm on the ohm setting.

Start with the lowest setting in the volt and ohm ranges and increase if no proper reading.

[wreksta]

Re: baird 42 flickering strobing wont start up

Update replaced the power supply board
and guess what still the same flashing strobes not turning on where to start now other ways to test inverter with multimeter

don't have any car bulbs

[tom66]

Re: baird 42 flickering strobing wont start up

Well poundland have got two 65W headlamps for £1 (get two packs) so I'd check there, they are pretty useful for testing power supplies, do not rule out possibility that your new power supply is bad, as all the tests showed it was not working well.

[vinceroger69]

Re: baird 42 flickering strobing wont start up

you may also want to try heating the whole psu up with a hair dryer for about 4 mins they see if you still have the same issue with it flashing also whats the full model number of the tv from the sticker on the back of the set.