Chosen Solution
Hello TV techs! Just replaced the PCBs on my defective Samsung TV and still have the same failure. No raster, no audio and no back lights. Perhaps I bought a defective main board! Back lights come on after removing power to the main board. Back lights come on after disconnecting the left ribbon cable T-Con, lights do not with the opposite configuration. Still have the 5 power light flash? BTW, I started repairing B\W Philco and Dumont TVs in the 70s before getting into telecom in the USAF so I have not kept up with the technology. Are there any common component failures on the main board? I have the skills and equipment to R&R most components except for the CPU. I can do 0603 sizes. Thanks! Rob Update (01/25/2020) Ok guys. Thanks for all your help! I found my problem. In my own stupidity, I failed to look at the front of the tv after checking the backlights half dozen times. DUH! The panel is cracked. Really dumb eh? Technician failure! I’m going to bet the supply, main and tcon boards are good. Now I have 1 supply and 2 each main and tcon boards. thanks again! rob
@goingback2tubes lets start off by following Samsung’s Fast Track Troubleshooting. See where this takes you and let us know what you get.
Hi @goingback2tubes , When you say “Just replaced the PCBs……” do you mean all of them or only the mainboard? Have you checked the voltages on the power board as per what is printed near the connector to the mainboard to make sure that they are all OK? There is usually also a fuse on the TCON board, have you checked that there is power there at all or if the fuse is OK if you haven’t replaced the TCON board? If it comes down to board level repair you may wish to invest in the service manual (couldn’t find a free one online) and see if that helps. I couldn’t find a schematic for the mainboard (BN94-10057N?) or even the power board either (BN44-0080A?) You may have better luck.
