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Mike G.
Mike G., Technician
Category: TV
Satisfied Customers: 6415
Experience:  10 Years Audio Video Repair & Setup
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I have a Samsung LN40B530P7F lcd tv that is going to black

Customer Question

I have a Samsung LN40B530P7F lcd tv that is going to black screen every 2 seconds then a proper picture pops up for 2 seconds lather rinse repeat, audio continues working properly at all times. I am one of the computer experts on here and I am stumped
Submitted: 8 months ago.
Category: TV
Expert:  Mike G. replied 8 months ago.

Welcome fellow expert.

This sounds very much like the Inverter board is failing. The board that supplies voltage to the back lights inside the display screen... You may be able to find the board on eBay for less than $100. I can check on that if you plan on DIY, let me know.

Mike

Customer: replied 8 months ago.
ok how can I test said inverter board without spending a 100 on parts swap troubleshooting?
Expert:  Mike G. replied 8 months ago.

There are a few different Power/Inverter boards for this model, so you have to take the back off the tv and verify yours before you replace it.

Customer: replied 8 months ago.
I am a computer expert on just answer and an electronics technician, testing procedure before I spend 100 or more on a parts swap/shotgun troubleshooting method?
Expert:  Mike G. replied 8 months ago.

You cannot test the high voltage output of the inverter board unless you have a 10kv meter.

Customer: replied 8 months ago.
which I do have, see also electronics technician........
Expert:  Mike G. replied 8 months ago.

Two possible board part numbers:

BN44-00264A

BN44-00197A

Search eBay for boards.

Or you can get "repair kit" with components to solder onto the boards for a lot less.

Customer: replied 8 months ago.
also supplied with Wells solder sucker and an iron.
Expert:  Mike G. replied 8 months ago.

go for it. let me know how it goes.

Customer: replied 8 months ago.
removing the back as we speak
Customer: replied 8 months ago.
heh sticker says no user servicable parts inside, I suppose that doesnt apply to us
Expert:  Mike G. replied 8 months ago.

ha

Customer: replied 8 months ago.
board identified as 264b
Customer: replied 8 months ago.
rev 1.0
Expert:  Mike G. replied 8 months ago.

When the picture goes out and sound continues, are the back lights still on (tv screen glows in a dark room), or not?

If not, then try this $27 power/inverter repair kit:

http://www.ebay.com/itm/141586874996

If that doesn't solve the issue then the back lights inside the display screen are bad and you are done because those cannot be replaced.

If the screen continues to glow while picture blinks out, then it is a sign of a TCON board issue.

Customer: replied 8 months ago.
the backlight is still functional when it blinks out
Expert:  Mike G. replied 8 months ago.

Then actually may be the low voltage line from power board to tcon board is dropping (may be bad caps on the power board check for bulging tops on caps). Or rather a defective Tcon board (no trouble shooting for that, just replace board).

Expert:  Mike G. replied 8 months ago.

http://www.shopjimmy.com/catalogsearch/result/?q=LN40b530p7f+t-con

Customer: replied 8 months ago.
does this tcon board hide under the power board or something because I'm not seeing it, btw caps on power board appear fine
Expert:  Mike G. replied 8 months ago.

tcon may be under a thin metal shield. either along top edge of screen or botton edge. has one ribbon cable coming from Main board (board with audio/video jacks).

Customer: replied 8 months ago.
ok the catalog pics showed the rear of the board no wonder I couldnt see it
Expert:  Mike G. replied 8 months ago.

ah

Customer: replied 8 months ago.
ok, let me leave this question open, I'll get one overnighted and see what happens
Expert:  Mike G. replied 8 months ago.

no problem

Customer: replied 8 months ago.
you have been great, I will accept for sure when we resolve this
Expert:  Mike G. replied 8 months ago.

ok let me know