Vizio E371 Completely Dead

[hanks424]

No amber Vizio, LCD TV completely dead.

Power supply outputs 5v, outputs 12v and inverter backlights when pins 3 & 4 supplied 5 v via 100 ohm resistors with voltage & video board disconnected. Power supply OK?

All fuses on both boards OK, caps look OK, could only find 2 regulators on video board (UP3 UP13) both have extremely low voltage (165 mV in .8mV out)

Any ideas how to proceed?

[ecking767]

Re: Vizio E371 Completely Dead

check the main CPU for over heating. Plug in the power cord.

[hanks424]

Re: Vizio E371 Completely Dead

No difference: cold start 82.3 degrees, plug in power, temp stays @ 82.3

[budm]

Re: Vizio E371 Completely Dead

What DC voltages do you get at both ends of the two fuses on the main board with ref. to chassis ground?

[hanks424]

Re: Vizio E371 Completely Dead

On the main board I read 5.1 volts both sides FP1, and 5 mV both sides on FP2 (should be 12 v). Obviously the video board is not turning on the 12v supply. As mentioned the power supply outputs 12v when triggering it alone via on-off pins (3 and 4)

[hanks424]

Re: Vizio E371 Completely Dead

The power board checks out OK (380 volts across capacitor) - problem is no turn-on signal from the video board. Can anyone help with a schematic or circuit description for this board? Does EPROM control feedback to power board? Since we're not getting amber logo on startup, I'd like to focus on the components that trigger turn-on signal.
Ideas welcome :-)

[budm]

Re: Vizio E371 Completely Dead

"The power board checks out OK (380 volts across capacitor)" PS_ON must be OK, otherwise the PFC Voltage booster will not be working to put out 380VDC on the main cap.

[hanks424]

Re: Vizio E371 Completely Dead

To BUDM: PS_ON is not functioning via the video board. Video board was disconnected -- I turned the 12v bus and inverter trigger on manually at the power suppy.

I'd really like to run this down -- lost without schematic

[budm]

Re: Vizio E371 Completely Dead

Sorry, memory lapse.