Re: Vizio VX42L NO picture, good sound and LCD

Took your suggestion and disconnected the ribbon from MAS to TCON, but still nothing on the tubes at all. I even turned the light out in the garage to see if there was something faint, but no luck.

I found 1 fuse on the TCON and it was good.

Found 1 LDO and is seems good.
RT9164A
15CG9L OK
1:0v
2:1.5v
3:3.3v

There is an LED MD1 on the master only, that lights up bright when you power on the TV, but fades off within 1-2 seconds. Unfortunately I dont know...

Re: Vizio VX42L NO picture, good sound and LCD



no flash or any signs of life from the backlights.

found 1 fuse on each inverter, both boards measured to be good.

+ lead of each cap to +24V is 0.0 ohms
+ lead of each cap to the other + cap lead is 0.0 ohms
- lead of each cap to GND is 0.0 ohms
- lead of each cap to the other - cap lead is 0.0 ohms.

We have capacatince meters at work, so if I get time, I'll try to measure the boards tomorrow. obviously will have the 2 big caps in parallel as well as...

Re: Vizio VX42L NO picture, good sound and LCD



Ok, looked a bit closer and it seems as though on the master bd the On/Off from the pwr supply board goes to ON/OFF2 on the mas/slav ribbon. On the slave these two are connected together, so ON/OFF1 on the master will have the ~3v when the slave is connected. ON/OFF1 goes through a 10k resistor an then to pin16 on the IC (labelled as STB) which is also pin 10 on the mas/slv ribbon.

Just checked and on both the master and slave, ON/OFF1 and ON/OFF2 are both at 2.88v and STB is at 0.7V

looks...

Re: Vizio VX42L NO picture, good sound and LCD



I'm not so good either, but one of the tech's at work called it "ugly but functional"

I measured res between the cap's leads and the +/- power rails and got 0.00 ohms. Is there a better way to test?...

Re: Vizio VX42L NO picture, good sound and LCD



I've tried looking at the IC's spec sheet, but couldn't find a good idea which one is the "on" line for the IC.

for the inverter boards:
There is an 11 pin ribbon cable connecting the master-slave inverter boards:
1:SS
2:VREF
3UTY_OUT
4:GND
5:CT_SYNC
6:GND
7:SRT
8:ON/OFF1
9:ON/OFF2
10:STB
11:GND

There is also a 4 pin ribbon cable going from the master to the TCON bd, but no clues as to what's...

My vizio VX42LHDTV10A had the screen go blank.
No previous flickering, etc.
Yellow logo on standby, white when powered on.
TV turns on/off normally and stays on or off.
LCD is working, verified with a flashlight shining into the screen.
Sound is working.

Checked power supply board for bad caps, but all look good.

with TV on, voltages from the power supply board are:
24V is 24.2V
5V stby is 5.17V
12V is 11.69
"A" is 2.89V (bl_on?)
"B" is 5.02 (brightness?)
PSON is 3.12...

Re: New Members - please post your introductions here

I'm from florida and an electronics/software engineer. Looking to fix my tv and finding the boards very useful.