Have a Hitachi 53sdx89BA Rear Projection TV. Turn on TV and red power light illuminates. No picture, but have sound. Check PC board in back and red led is flashing and green leds are lit. It was working...
Discharged Flyback Transformer. Removed main pc board from bottom of TV and flipped over, no apparent damaged components or blown board traces were found. Noticed a lot of flux in various areas on the board that seemed unusual (maybe TV was worked on before as I bought a showroom demo at Circuit City). Used a plastic screwdriver to remove all flux between connections on ICs, Transformers, Flyback Transformer, and various other components. Cleaned all debris, dust and crud accumulation (TV is over 10 years old and there was alot around the Flyback Transformer) from both sides of board using a lightweight paint brush.
Used a magnifying glass to check all solder joints for possible cold solders and found none. Did the same for Power Supply Board. Checked various ICs and Power Transistors for opens or shorts (in machine) and they seemed fine. Reinstalled boards, said a few Hail Mary's and fired it up.
The protector Led no longer flashed under power and lo and behold I got picture and sound!
I cleaned the lens on the projectors (again 10 years of dust accumulation) did a magic focus adjustment and it works fine!
After reading other fixes, I fully expected it to die after 10 minutes so I left it on all day and against all odds it still works.
What was the fix......Dirt buildup on and around Flyback and other components,,,,,,Flux conducting electricity between contacts on Flyback and other components.....or oxidation on connectors between Power Supply and Main Board.....I don't know.... all I know is that for the moment I saved around $ 300 - 400 in repair bills by doing it myself.
Feb 01, 2010 |
Hitachi 53SDX89B 53" Rear Projection...