Samsung ln40a530p1fxza Loud screeching noise no screen

[gringoboy6]

Hello Everyone,

I am new to this forum and the world of electronic repairs lol. My nephews tv is down and im trying to be the hero of the day.

The tv does not not turn on and only has the standby light on. I was told before it completely shut down it use to come on and the screen would look "crazy" and make a loud high pitch screeching noise then shut off .

So far I -

looked at the caps none are bulging

disconnected the tcon from motherboard and nothing

I jumped the powersupply with pin 1-3 and 1-5 and the back lights came on and stayed on

I read that it could be the main boards graphic card so I "Baked" the card in the oven for 8 min at 400 degrees to reflow it. after i let it cool down i put it back in and the tv came on and i went to the menu screen but then it shut off again and shortly after it turned off i heard a click for the first time as well

Any help is much appreciated thank you.

[Shinju]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

Mainboard issue, I have one that does this. It would turn on the screen would be all scrambled, it would turn off and back on and squeal out of the speakers with a normal picture. It would turn off and back on a few times then be normal.

Fixing the caps on PS did help it but it still does the squeal and scramble upon the first power up if it has sat for awhile.

I am pretty sure its the same unit as the one you have listed too.

I have seen this affliction on a few Samsung panels.

[gringoboy6]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

Is there any way to fix this without ordering a new main board?

[gringoboy6]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

bump

[gringoboy6]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

Hello can you guys help or confirm the main board is doa ? lol i don't mind getting my hands dirty

[Shinju]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

I am not sure how you would go about testing CPU issues, if the mainboard is less then cost of a new tv I would do that.

I don't think you can really fix the issue with out some serious tools like a O-scope, hot pad and extensive surface mount soldiering.

I left mine as is because it works if used regularly if i leave it off for more then a day or two it acts up on power up but is fine after that.

[gringoboy6]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

You said that you changed the caps on the psu were yours bulging?

[Shinju]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

2 out of the 6 1000uf caps were bleeding out of the top. I replaced them all.

Take the back off you set and snap some photos of each of the boards as clear as you can.

[Glitcher]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

can you post close up photos of the main board (back and front)? Since this is LCD I'm not certain if this is the same main board such as the ones in the plasmas where there's one ceramic cap that causes the screeching problem.

[Shinju]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

Squeal coming out if the audio speakers or something else? Mine is coming out if the audio curcuit when the unit powers on after it's been off for awhile.

[gringoboy6]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

Okay here are the pics let me know if you need a more clear image or closer shot i added the psu as well. The sound is coming from the speakers at least what I think. It has only made the sound 2 times since i have been working on it.

[budm]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

What is the power supply P/N? BN44-??????

[gringoboy6]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

bn44-00197

[gringoboy6]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

I have to tuck in for the night lol so ill be back on tomorrow to check out your response thank you for your time

[budm]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

Is it 197A or 197B, tom66 has the diagram for your board.
http://www.toms-service-manuals.com/

[gringoboy6]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

It's a

I see it what do I do next ?

[budm]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

I already exceed the download limit today from his site, so is it A or B?

[gringoboy6]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

It's A

[budm]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

OK good, I download both A and B earlier. So let me look at the diagram.

[budm]

Re: Samsung ln40a530p1fxza Loud screeching noise no screen

OK report the DC Voltage readings on each pin of CN801 when TV is OFF and when TV is ON.
for example:
pin 1 Power ON/OFF = xxV (OFF), xxV (ON)

I believe you have main board problem.