Question about Sharp 20F640 20" TV
I have a Sharp TV and I turned it off and noticed a beeping noise somthing simular to a cricket. When I went to turn it back on it didn't work. The power light didn't come on or anything.
The "cricket" sound you heard can mean any number of things:
1. A component in the power supply that sets the frequency failed, causing a high frequency (hence over-voltage) in the SMPS, which then also failed. The initial failure may have occurred in a small high-voltage capacitor in the power supply (around 160V or so rated)
2. A failed horizontal drive or vertical stage, which drew so much current that the switching semiconductor in the SMPS failed.
Note that such failures often occur like dominoes (one, then two, then three, and so on). Sometimes the fuse itself will not even blow out. The best thing to do is to first remove the line-output transistor and then replace the switching semiconductor(s), nearby zeners, capacitors, and fuse if blown. Then turn the unit on and check for about 105V on the collector terminal of the line transistor. If that's fine then turn unit off, replace the line transistor.
Of course the above procedure is only a guide; the precise steps taken will depend on your exact make and model. Also, if the above sounds mind boggling then rather take it down to your nearest repair shop. Good luck.
Posted on Jan 18, 2008
A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Jul 05, 2009 | RCA D52W20 52" Rear Projection HDTV-Ready...
Apr 07, 2009 | Hitachi 50V500 50 in. HD-Ready LCD...
Apr 30, 2008 | RCA P56950 56" Rear Projection Television
Jul 29, 2007 | RCA P52926 52" Rear Projection Television
Oct 05, 2017 | Sharp 20F640 20" TV
187 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: