Sylvania 6620lg 20" tv

You can download a manual here: https://www.manualslib.com . You can also check out how to use the TV buttons to set it up .

Check all the connections to panel from T'Con board. Re-seat all the flat cables there. Any loose connection to these cables to their sockets will be the problem.

Does the set have any audio/video jacks on the back? Have you tried hooking to those?

If the tuner is bad cable can be hooked via a box or even using a old vcr to the rear jacks===switching to that input and bypass the tv tuner.

It will also tell you if problem is with the tuner.

Let me know if you have questions.

Look at the power supply first since it is easier to get to, look for burnt parts, bad capacitors, etc.
http://en.wikipedia.org/wiki/Capacitor_plague
Please post back what you find.

You probably have bad 10v 1000uF capacitors on the power supply board. Replace with 16v.

you need to get to the menu and change your tuner mode from cable to t.v antenna air signal

In the past the main board is usually the problem but you might go to Phillips website and look for technical support there may be some software upgrade you coud install very easily with a thumb drive. Main boards could range from 150 to 300+ go to shopjimmy.com they may have it

Do these faint lines show up in all inputs

replace the main board inside the set.

The ;quick answer is YES, you will need a converter box to receive digital broadcasts. This set has only an analog tuner built-in. That is why it is HDTV "ready" (ready for you to add a tuner).

As for HDTV vs EDTV it is a matter of resolution. Your set is capable of EDTV resolution, which is better than SDTV (standard definition TV) but not quite as good as HDTV. With a digital tuner you will be able to view all digital programming, even HD, and it will look excellent, though not quite as sharp as a set with higher definition.