Panasonic Viera TX-26LMD70 Powers off after a minute....
Hi everyone,
When plugging in it powers on for around a minute or 2 depending how it feels, everything is working during that time, picture looks good. Then powers off with green led continuously flashing fast.
I have replaced the 3 filter caps on the PSU and the 2 filter caps on each Inverter board to no avail.
I was thinking could be tired backlight CFL's? But unplugging the signal cable to the Inverter and the backlight will stay on fine (I had to jump the MOSFET that turns on power to the inverter on the PSU as the set will not turn it on with the signal cable removed from inverter.
Any thoughts? I have schematic for the PSU, I think this is working since all it does is output 24V.
When plugged in the 24v for the main boards is always on, the inverter power turns back off when the set turns off but I jumpered the MOSfet so is always on to inverter, makes no difference.
On the PSu to next small power board along the top (see pic), there is 3 wires apart from 24v:
GND,
24V,
24v Det - 2.96v when on leads to missing components on PSU (missing from factory).
Sub_on - 3.22v when on then pulses on/off when set switchs off but strangly the PSU keeps the 24v on unless I remove the whole connector.
Inv_On - 3.22v is on when set is on and off after it goes off.
I have schematic for the PSU board, I have schematic for another chassis that contains the MAIN 2 boards called DG board but not service manual for whole TV and not include second Power board along the top.
The inverter has following data lines:
Err out on - I dont understand it - 3.15v when on, is generated from Main board, dis-connecting and backlight does not come on, does it mean error???
ext_pwm - 3.13v, what is this?
on/off - 3.24v - I assume from mainboard to turn on inverter but disconnecting whole cable and inverter is on all the time!
VBR-a - 3.14v - is it variable brightness?
Many thanks.
Hi everyone,
When plugging in it powers on for around a minute or 2 depending how it feels, everything is working during that time, picture looks good. Then powers off with green led continuously flashing fast.
I have replaced the 3 filter caps on the PSU and the 2 filter caps on each Inverter board to no avail.
I was thinking could be tired backlight CFL's? But unplugging the signal cable to the Inverter and the backlight will stay on fine (I had to jump the MOSFET that turns on power to the inverter on the PSU as the set will not turn it on with the signal cable removed from inverter.
Any thoughts? I have schematic for the PSU, I think this is working since all it does is output 24V.
When plugged in the 24v for the main boards is always on, the inverter power turns back off when the set turns off but I jumpered the MOSfet so is always on to inverter, makes no difference.
On the PSu to next small power board along the top (see pic), there is 3 wires apart from 24v:
GND,
24V,
24v Det - 2.96v when on leads to missing components on PSU (missing from factory).
Sub_on - 3.22v when on then pulses on/off when set switchs off but strangly the PSU keeps the 24v on unless I remove the whole connector.
Inv_On - 3.22v is on when set is on and off after it goes off.
I have schematic for the PSU board, I have schematic for another chassis that contains the MAIN 2 boards called DG board but not service manual for whole TV and not include second Power board along the top.
The inverter has following data lines:
Err out on - I dont understand it - 3.15v when on, is generated from Main board, dis-connecting and backlight does not come on, does it mean error???
ext_pwm - 3.13v, what is this?
on/off - 3.24v - I assume from mainboard to turn on inverter but disconnecting whole cable and inverter is on all the time!
VBR-a - 3.14v - is it variable brightness?
Many thanks.
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