Have TV Questions? Ask a TV Technician
Welcome to the site! I'm Dan. Please reply back so I know you're here. Also, are you with the unit now?
OK, did you replace the whole boards or just components?
Interesting. SDR have nothing to do with sound. Do you know if the plasma panel is charging?
Turn the TV off, and make the room as dark as possible. Get a good idea for how pitch black the screen is. Now turn the TV on and watch the screen. I know it’s still black, but did the screen seem to lighten up, even slightly? It might appear dark blue, gray, or even dark purple.
That's how I check to see if it's charging.
OK, once we know if it's charging we can narrow our troubleshooting. Also... will you have access to the back of the TV tomorrow, while the TV is on??
Oh... and do you have a multimeter?
OK, there are 2 checks I want to do...
- Disconnect the power cord
- Lay the TV face down on a sturdy table that has been lined with a blanket
- Remove the entire rear panel assembly (lots of screws... keep track)
- Standing behind the TV, find the Ysus and Zsus. Note... the SDR boards attach to the Ysus. The other large board on the far right side is the Zsus
- Connect the power cord and turn the TV on (check for priming here)... now let it sit for 30 minutes turned on
- Touch the heatsinks on the Ysus board, using only one hand... do the same for the Zsus
- Are any of them still at room temperature, or cooler? If so, which ones?
- Leave the TV turned on
- Set your meter to DC voltage (DCV, VDC, whatever... it's usually the "V" with the straight horizontal lines over it)
- Black lead goes to any exposed chassis metal for ground
- Red lead goes to the VS test point on the power supply board
- Do the same for the VA test point.. report back with both voltages
Let me get you a picture showing where VS and VA are.... stand by.
Wait... need your TV's model number so I can get you the right picture. Post back when you can.
Yep, we can handle this. No problem. OK I'll go ahead and give you a picture of a super common Hitachi power supply. Yours is really close to this picture. Click >>HERE<<.
See that red box I outlined? There are 3 pins inside that box. Your meter's red lead needs to test each of those pins... one at a time. Keep the TV turned on, and the black lead grounded to any exposed chassis metal (I like to use a screw that's holding the board in place).
Yep. I work M-F so I can't always respond quickly during the day... but I'll get back to you as soon as I can.