TH65PZ850U, TH58PZ850U, TH50PZ850U, TH46PZ850U, TH58PZ800U, TH50PZ800U, TH46PZ800U, TH42PZ800U, TH50PZ80U, TH46PZ80U, TH42PZ80U, TH50PX80U, TH42PX80U, TH50PZ85U, TH46PZ85U, TH42PZ85U.
How to perform a hard reset to Panasonic Plasma TV
Normally; a hard reset can be done by unplugging the TV from AC mains wall socket, and re-plug it back after some minutes or hours.
To perform HARD RESET of Plasma TV unit by pressing & holding VOL DOWN(-) on unit and MENU button on remote at the same time for about 3 seconds. This must be done if you replace the main board of the TV. All new A boards supplied from factory needs to be initialized.
After the main board replacement. once AC power cord is plugged in, unit will turn on by itself. Depends on factory settings, unit will either display Video, Component or Tuner icon. After few seconds, screen will change to service mode automatically. NOTE: Since unit is in service mode, only buttons 1, 2, 3 or 4 on remote are working (rest of buttons are nonfunctional). After hard reset, confirm if Plasma TV powers ON in user mode and check overall functionality.
FAULTS TO 46" PLASMA TVs
* The unit shuts down and power LED blinks 10 times.
> Shorted Q409 & open PR401. Replace Q409 & PR401
Speaker box is making rattling sound; contact with cabinet parts
* Vibration noise from left or right speaker. Speaker box is making direct contact with cabinet parts.
> Installing mounting screw in the center of speaker box prevents from touching the cabinet parts and minimizes the risk of vibration noise. Install screw, part number THEL049 to both speaker boxes as shown here. Repeat the same for left speaker box.
Relay clicks then TV shuts down with power LED 10 blinks
* When AC cord plugged in, relay clicks then TV shuts down with power LED 10 blinks.
> No Vin supply to IC520 (power control IC) due to open R712 & shorted C527.
Replace R712 & C527
R712: ERJ6GEYJ4R7
C527: ECJ3YB1E475K
Picture disappears after a few minutes, but sound is OK.
* Low Ldo_5V supply to IC9800 (DC to DC Converter) due to leaky D9801.
> Replace D9801 on the D board.
D9801: B0JCDD000002
Shuts down with power LED 10 blinks.
* Missing 395Vdc output due to shorted Q412 & Q413 and open PR401.
> Replace Q412, Q413, PR401 & check/replace Q408 and Q409. Note: Always confirm condition of Q408 & Q409, in some cases could be shorted.
Q412 & Q413: B1DEGQ000070
Q408 & Q409: B1DHCD000034
PR401: K5Y502BA0001
