Riddled TV Repair Forum

BillsVX · Joined: 09 Jul 2008 Posts: 2

I have a JVC 27" Television Model #AV-27CM3. Ser# 08825881 Mfd. March 1993. I don't have the Chassis # at the moment.
Recently, the screen would go black while in use. I still had audio and the channels would change...just had no video. Cycling the power Off and On several times would sometimes bring the picture back.
Lately though, there is no picture when it is turned on for several minutes and cycling the power does not bring the picture back. When it does have a picture, it doesn't have it for more than a few minutes. When the power is turned off, the screen has the color "Butterfly" visible for a few minutes after, so I assume it's getting HV to the CRT.
Could this be a video driver problem? Any particular place to look first other than a good visual inspection of the internals?
Any help would be greatly appreciated.

Google

Jesse Mack · Joined: 22 May 2008 Posts: 600 Location: The Last Frontier

Do a good visual with a bright light and a magnifying glass of the solder points of IC421 (vertical output IC). This IC is mounted on a Heat Sink of medium size. The IC421 designation is printed on the circuit board next to the IC. Make sure the set is unplugged before proceeding.

If you have a vertical collapse condition the picture will blank out. This is to prevent the picture tube from becoming damaged.

Let me know if you need any more help.

Jesse

BillsVX · Joined: 09 Jul 2008 Posts: 2

Jesse: Thanks, I'll get the back off of it and let you know what I find out.

Bill