baird 42 flickering strobing wont start up

[wreksta]

Re: baird 42 flickering strobing wont start up

right my findings are

inverter 10 pin
5 pins gnd
5 pins fluctuate never hit the 24.0 always from 00.5 when spiking hit max 23.0

audio 4 pin

2 pins 24.0 same as inverter
2 pins gnd

main av
all the values are the same here all from 0.5 without the spiking they never hit there correct voltages
if you get what I mean so +12v never hits 12.0 always below

1 +12v
2 +12v
3 sgnd
4 sgnd
5 sgnd
6 +5v
7 +5v
8 5vsb
9 stb
10 +5v
11 +5v
12 sgnd
13 sgnd

[notallbad]

Re: baird 42 flickering strobing wont start up

Could you describe what the tv does in a bit more detail.
From turning on power from the mains socket?
Then switching the TV's rocker switch, if it has one.
And finally, actually turning the tv on, either from remote or keypad (front/side control) Power On button.

What the front power light does, colour and flashes
Backlight, ok strobing
Any display on the screen

Does the tv work perfectly fine other than the strobing?

[wreksta]

Re: baird 42 flickering strobing wont start up

Could you describe what the tv does in a bit more detail.
From turning on power from the mains socket?
Then switching the TV's rocker switch, if it has one.
And finally, actually turning the tv on, either from remote or keypad (front/side control) Power On button.

What the front power light does, colour and flashes
Backlight, ok strobing
Any display on the screen

Does the tv work perfectly fine other than the strobing?

tv don't power up upon plugging and pressing switch it starts to strobe for a lil bit then stops then strobes in a continuous cycle standby lit all time unless rocker switch pressed buttons on tv don't do anything

[vinceroger69]

Re: baird 42 flickering strobing wont start up

You could with a 1kOHM resistor jump the PS ON pin (not to be confused with the BL On pin) and 5v stby pin, with main A/V b/d connector disconnected.

can you try this with all the connectors disconnected i wonder if its a eprom issue on the main board? see if voltages still varies

[notallbad]

Re: baird 42 flickering strobing wont start up

Yes, sounds like it could be. Up til now we (well I) assumed the tv powered up and worked, just that the backlights were strobing.

If you don't have a 1kohm resistor just disconnect all connectors from the PS b/d then with DMM check that main filter cap with power on as you did for Tom earlier (see Post #11) just to see what voltage you get. Should be around 320v.

[wreksta]

Re: baird 42 flickering strobing wont start up

that main filter cap is the big lying down one isn't it

but I still need main power to the board just disconnect these
av main
audio
inverter all from psu yes

also I desoldered that right heatsink does it have to go back on just for a voltage check

[notallbad]

Re: baird 42 flickering strobing wont start up

Yes, as before careful not to cross the probes

Only connector left should be the mains inlet connector.

Dont bother with the heatsink as long as the PS is only on for a short period. The heatsink disperses the heat generated by the diodes/transistors screwed to it, without it and run for too long they will overheat and get damaged.

Do you have a 1k ohm resistor (or something close to it)? You ideally need one to get the PS fully running to check the voltage on that cap.

[wreksta]

Re: baird 42 flickering strobing wont start up

meter set 600 vdc with all disconnected cept main power in
big cap gives me 330 either way on the probes
20vdc and 200vdc give me nothing

[notallbad]

Re: baird 42 flickering strobing wont start up

Is the reading steady? It may go up to 331 or go down to 329 occasionally but thats fine as long as its not unstable, i.e jumping around erratically.

With the probes reversed you should get a - (negative) reading but the value will be the same.

With DMM on 20 V DC, you can only take a reading of up to 20v, with DMM set to 200 you can only take a reading of up to 200volts.
You have measured 330v which is within 600v setting so that is correct.

[wreksta]

Re: baird 42 flickering strobing wont start up

yeah it does not bounce fluxuate 330 steady

[notallbad]

Re: baird 42 flickering strobing wont start up

thats good

do you have a resistor?

[wreksta]

Re: baird 42 flickering strobing wont start up

got loadfs on different boards need the colours to help me mate

[notallbad]

Re: baird 42 flickering strobing wont start up

Use the DMM set to the ohm 2k setting, one probe on each end of the resistor will give you the resistors ohms, unsolder a few and check them, you may be lucky.

look for ones like these and unsolder and check with the DMM just to be sure, but these should get you in the region of 1k ohm or 1000 ohms
3 band brown black red possibly
4 band brown black red don't matter about the last one thats just for tolerance
5 band brown black black brown don't matter about the last one thats just for tolerance

For 1.2k ohm
3 band brown red red possibly
4 band brown red red don't matter about the last one thats just for tolerance
5 band brown red black brown don't matter about the last one thats just for tolerance

[wreksta]

Re: baird 42 flickering strobing wont start up

ok then what do I do with that lol
ps-on wheres that I know the stb is on main av connector on psu

[notallbad]

Re: baird 42 flickering strobing wont start up

OK, lets see!

Looks like its Pin 8 and Pin 9, thats going by how you have numbered and labelled them in Post #61

[wreksta]

Re: baird 42 flickering strobing wont start up

I only have 2000k'200k'20'2000'200 on the meter on ohms

[notallbad]

Re: baird 42 flickering strobing wont start up

Set it to 2000, NOT 2000K

You want a resistor thats around 1000 ohms

[wreksta]

Re: baird 42 flickering strobing wont start up

what do I do with it mate when I find one
I don't hold it do I

[wreksta]

Re: baird 42 flickering strobing wont start up

bugger can seem to find one can I not use 2 470 Ohms 5% or I will keep looking

[notallbad]

Re: baird 42 flickering strobing wont start up

soldered in series (end to end) will give you 940 ohms which is close enough but check them once soldered to be sure they are good and you get a reading of around 940 ohms