Unreliable start. Mostly Led flashes red once every 4 secs suggesting Power Unit or LCD Panel. No Start
Sometimes normal start
Thanks for any help.
Tony
Manufacturer: Panasonic
Type: TX-L42ETW5
Chassi: LA35
Hello everybody,
I could determine or measure the following with the device:
Device does not start anymore, stand-by LED lights red when device is plugged in and flashes red as soon as an IR command (key press) is sent via the remote control. Voltages of power supply STB 5V and signal LCD_TV_SUB_ON come from A-board. Power supply starts, supplies P15V and SUB1.1V, 1.5V, 1.8V, 3.3V, 5V, HDMI3.3V and USB5V are generated on the A-Board (stand for about 2.5 seconds). Then signal LCD_TV_SUB_ON goes low (voltages go away to STB 5V) and after about 2 seconds back to high (endless). What is missing is the voltage PNL12V which is switched on by PANEL_VCC_ON2. PANEL_VCC_ON2 always has a low signal and does not change its state. Power supply also provides for the 2.5 seconds the 24V for the backlight. Clocking of LCD_TV_SUB_ON starts immediately after plugging in the mains plug (also without IR command). SOS error code is not output. The over-voltage circuit in IC 5000 pin 7 also does not respond. Attached is the timing diagram from the technical training of Panasonic where I have drawn until when the boot process behaves normally.
In my opinion a mistake on the A-board? Does anyone have a tip?
greetings
Andi
Sziasztok!
Panasonic TX-P42U20E plazma készenlétből nem indul. Relé kattan és a készenléti LED pirosan 1-es hibakódot villog.
Egyszer volt olyan, hogy elindult, kb 3 percig jól is működött, de 6-os hibakóddal leállt.
A tápban 1000uF 230V enyhén púposnak tünik, de cserélve semmi változás .
Y-on nem látok zárlatot.
Üdv: Wolf
Üdvözletem!
Van nálam egy Pana plazma tv. Amikor bekapcsolom akkor minden feszültség megvan rajta.(Vsus Kb 5 mp múlva kapcsolnak a relék és kikapcsolja a tápot.Biztik rendben. X-Y Maineken átmértem a FET-eket. Tápban is átmértem. A készenléti LED egyszer pirosan villan aztán zölden vibrál gyorsan utánna kezdi előről. Ha valakinek van valami ötlete, tapasztalata szivesen várom a segítségét.
üdvözlettel Tamás