Samsung le46b530p7w

[sordids999]

hi
anyone got any ideas on this problem please
my main tv has just started to play up the screen goes black but i still have audio,so i ordered a new invertor board due to still being able to see images when i shined a torch onto the screen.
the tv is fine until i plug in either a hdmi lead or a scart lead into the main board then the picture just goes ?
tested voltages on power supply they seem fine
maybe the screen is shot time too bin the tv ?

thanks

[munirutech]

Re: Samsung le46b530p7w

what are the voltages you are getting from the psu to the inveter board?

you should expect this two important voltages 24v and 5v for BLON

[sordids999]

Re: Samsung le46b530p7w

the cable going to the invertor is reading 12v like it says on the psu

[tom66]

Re: Samsung le46b530p7w

That is actually error signals from balancer, you need to check BL ON OFF from main board to power board, that being said it is unlikely the balancer board (not inverter) would cause this. There is a jumper JP852 that needs to be cut to fix this issue -- design error by Samsung.

[sordids999]

Re: Samsung le46b530p7w

ok tom found it so what now ?

thanks

[sordids999]

Re: Samsung le46b530p7w

ok now the tv seems to be staying on for now !

thanks tom your a star !

[tom66]

Re: Samsung le46b530p7w

Nice to hear. This issue also affects 55" but strangely not 40", and only B and C series Samsung LCD. Something to do with the AC detect circuit -- bane of my life!!

[sordids999]

Re: Samsung le46b530p7w

ahhh now the tv picture has gone again with still audio

[tom66]

Re: Samsung le46b530p7w

Backlight still lit?

[sordids999]

Re: Samsung le46b530p7w

no tom

[sordids999]

Re: Samsung le46b530p7w

its strange if i go into the menu and change the picture mode then i just have audio so left it off for a while and it worked fine when i turned it back on,so changed the picture mode again and back with just audio

[sordids999]

Re: Samsung le46b530p7w

Ok worked for 20 mins then just audio again

[tom66]

Re: Samsung le46b530p7w

Check the voltage across the two large 450V capacitors.

[sordids999]

Re: Samsung le46b530p7w

383v on both caps

[tom66]

Re: Samsung le46b530p7w

Does that remain through the fault?
BN44-xxxxxx[A-Z] number on power board?

[vinceroger69]

Re: Samsung le46b530p7w

tom would a eeprom reset help?

http://wiki.samygo.tv/index.php5/UnB...y_EEPROM_Reset

[tom66]

Re: Samsung le46b530p7w

Probably not if audio remains. If audio cut out too, I'd be thinking that might be a cause of the problem. (Watchdog mode, etc.)

[sordids999]

Re: Samsung le46b530p7w

Can't get the picture to come on now so can't see if the voltages drop

BN44-00265B REV 1.3
I46F1_9HS

[johnboy1313]

Re: Samsung le46b530p7w

Do you still see 383V across the caps while the picture is off?

[tom66]

Re: Samsung le46b530p7w

I have the schematic


Wait for it to fail. Then, check voltage across PCI801's secondary (UVLO.) If it goes high (>2V), then a short across PCI801 may disable UVLO completely. (The only real issue with this is that it might cause the backlight to flicker a little when it is unplugged while running. Hardly a real problem.)