TV Repair Questions? Ask a TV Technician
Initially, your most likely suspects are your Power Supply Board, or your Mainboard.
The first thing you would want to check for in the set, are the capacitors visually, making sure none are bulged, swollen or leaking fluid. The Power Supply is the board inside the TV that power cord directly attaches to.
Any that do not appear cylindrical, or are leaking you would take the rating (In uf), and the voltage off the cap (example: 2200 uf, 50 vdc), and cross reference them at the sites below:http://www.digikey.com/
They each solder into place with two leads, a positive and a negative. Make sure you solder the news ones in the same way, or they will explode when the TV is powered up.Make sure you are careful not to un-solder any other adjacent circuit traces when removing the old caps, and carefully solder in the new ones allowing the solder to flow into the joint. Replace any and ALL caps that are questionable. Remember- when in doubt, change them out.
Try powering up the TV, and if the set operates normally, then you have solved the issue by replacing the faulty cap(s).
If it does not, then you would need to isolate which board is causing the problem by measuring the Power Supply Voltages.
Please only proceed if you have experience measuring live voltages on a circuit board level.Use a DVM (Digital Volt Meter) set to DC volts, put the Black probe of the Meter on an RCA jack shield on the back of the TV, then use the Red probe and probe all of the Outputs for voltage (correct voltages will be stamped on the power supply at the outputs). Do this with NOTHING connected to the Power supply but AC power, the Mainboard, and the little board that houses the Power Switch. If a voltage is missing/ fluctuating, then the power board needs to be replaced.If the power supply outputs its rated voltages, then connect the other boards one at a time until one causes it to shut down. This board would have the short causing the supply to SOS, and would need to be replaced.A good source to locate replacement boards is http://www.shopjimmy.com/
If you need further assistance, let me know.
If this answers your question, please rate the answer accordingly, as it is the only way we Experts get paid for our knowledge on the site. Tips and Bonuses are welcome and appreciated!!
capacitors look good. voltage at power board
all boards are connected
sound was working. and by priming if you mean slight glow then no as stated.
when the tv went black the sound continued. As I tried to get the menu up I may have changed the input. I do get the initial jingle when turned on and I do not have anything hooked up to it now,
ok I am not sure which boards are which, but the board left of the power board 1 of the 8 heat sinks is warm. the long skinny board (long top to bottom ) on far left with 6 heat sinks has 1 of the 6 that is very hot. and the board on the right of power board all are warm. Also the set is turning off automatically which is probably because nothing is hooked up to it but IDK.
Please click the link below to identify which board is which and let me know again which heatsinks are warm, hot, and cold:
ok the y main board has 1 of 8 heat sinks warm others cold. the lower y scan drive has 1 of 3 heat sinks hot others warm, upper y scan drive warm. the x main board is all warm.
Hey I have replaced the following parts to no avail. There are only a couple boards left. Any suggestions.
I ordered and have yet to receive lower y scan drive.
OK replaced lower scan drive as well. nothing works.
seems like just the bottom 1 not much though.
just checked va and vs. still good. Screen does not prime. part of original problem.
yes 5 volts to main. xmain and ymain are warm , scan drives are just marginally warm.
yes. 30 min.
Sound- after the screen initially went blank I tried to go to the tv menue and changed the input so I dont know what input is live. I have the initial jingle when the set turns on and I had sound when the screen quit initially. but thats it no sound other than that.
the rest is correct.
I changed the main board and the video board. and 4 others . the only thing not new are the 3 boards at the very bottom and the 1 board at far right. so if panel is dead is there a test?
im giving up. going tv shopping. any suggestions? brand or type?
ok thanks, have a good day.