Good afternoon all -
I have another TV in hand. This time it's a Vizio VO420E. I picked it up for free the other day. The TV is manufactured in the 2008/2009 time frame.
Pictures of the boards and an overall view are attached. I checked the voltages on the power board.
Initial assessment
- There is some sign of life on the main board, but without schematics, i see that a few caps have 0V on either side, and a couple of LDO's and switching supplies have output voltages. I just don't know if the values are correct.
- The backlight does not turn on
- no sign of life with flash light test shining at screen
- The optical audio out does not illuminate red.
- The main board fuses near the power connector are okay -
-- F1 - 5.128V on both sides
-- F2 - 12.28V on both sides
Main caps
+165V across the main caps when off
+392V across the main caps when the power button is pushed.
The voltage across the main caps stay steady.
Power Supply - Connector CN201
Pin name, actual voltage read
ON/OFF, 0V (when off), 3.166V (when on)
+12, 12.27V
+12, 12.27V
+12, 12.27V
GND, 0V
GND, 0V
GND, 0V
GND, 0V
GND, 0V
ST/+5V, 5.194V
ST/+5V, 5.194V
ST/+5V, 5.194V
Power Supply - Connector CN202
Pin name, actual voltage read
DIM, 0V
INV_ON, 0V
VBR_A, 0V
No Connect
Status, 0V
No connect
Tests
- I was able to force the backlight on by removing the cable from connector CN202, and hooking up an external power supply to the INV_ON signal when the TV is ON.
- The backlights glow - at least the back lights work.
- I disconnected the ribbon cables between the main board and the integrated T-CON, no change in behavior.
- It appears that the main board is not running yet.
Request
- Does anyone have the schematics for the main board or the service manual for this TV? I was not able to find it online. I was only able to find the following brief service manual in online form only:
https://www.manualslib.com/manual/10...page=19#manual
I have another TV in hand. This time it's a Vizio VO420E. I picked it up for free the other day. The TV is manufactured in the 2008/2009 time frame.
Pictures of the boards and an overall view are attached. I checked the voltages on the power board.
Initial assessment
- There is some sign of life on the main board, but without schematics, i see that a few caps have 0V on either side, and a couple of LDO's and switching supplies have output voltages. I just don't know if the values are correct.
- The backlight does not turn on
- no sign of life with flash light test shining at screen
- The optical audio out does not illuminate red.
- The main board fuses near the power connector are okay -
-- F1 - 5.128V on both sides
-- F2 - 12.28V on both sides
Main caps
+165V across the main caps when off
+392V across the main caps when the power button is pushed.
The voltage across the main caps stay steady.
Power Supply - Connector CN201
Pin name, actual voltage read
ON/OFF, 0V (when off), 3.166V (when on)
+12, 12.27V
+12, 12.27V
+12, 12.27V
GND, 0V
GND, 0V
GND, 0V
GND, 0V
GND, 0V
ST/+5V, 5.194V
ST/+5V, 5.194V
ST/+5V, 5.194V
Power Supply - Connector CN202
Pin name, actual voltage read
DIM, 0V
INV_ON, 0V
VBR_A, 0V
No Connect
Status, 0V
No connect
Tests
- I was able to force the backlight on by removing the cable from connector CN202, and hooking up an external power supply to the INV_ON signal when the TV is ON.
- The backlights glow - at least the back lights work.
- I disconnected the ribbon cables between the main board and the integrated T-CON, no change in behavior.
- It appears that the main board is not running yet.
Request
- Does anyone have the schematics for the main board or the service manual for this TV? I was not able to find it online. I was only able to find the following brief service manual in online form only:
https://www.manualslib.com/manual/10...page=19#manual
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