Vizio SV420XVT1A no picture has sound

Status
Not open for further replies.
E

electronics_repair111

New Member
Hello,

I need help with troubleshooting a Vizio tv. Tv had a bad t-con board (processor and memory was burnt. Replaced t-con, when tv powered up the t-con's LED lit up blue then faded out while a screeching sound was emitted from the t-con. I didn't see a picture even when volume or menu button was pressed (back-light is on but no image at all). I disconnected the LCD panel (two ribbon cables) powered it on and it didn't make the screech sound. Is the LCD panel bad and overloading the t-con? Is there anyway to test the LCD panel? Any tips would be greatly appreciated.
 
Last edited:
Most of these failures are due to electrolytic caps. Look around the PC boards and see if one is bulging or leaking. If you spot one then replace all of the caps which look identical to the bad one(same voltage, value, temperature rating, manufacture).
 
I would imagine you've probably killed the new T-con board, possibly the HT rails are too high and destroying them?.
 
rmn_tech said:
HT = High tension (high Voltage) e.g. Vs=203v, Va=173v
Click to expand...

Not specifically - HT rails refers to the power rails in a unit, so 12V and 5V are 'HT' as well.

Historically it refers to 'High Tension', which was high voltage rails in valve amps etc.

LCD's don't have high voltage rails though, only high voltages in the inverter feeding the CCFL's.
 
I stand corrected Nigel I somehow started thinking Plasma. The plot has finally been lost

Anti ageing machine anyone.
 
Nigel Goodwin said:
How did you check?, either an ESR meter or a scope are the only ways.
Click to expand...

I did a visual (looking for pregnant ones) but I will break out the trusty ESR meter I could also look at the out puts of PS with a scope as well. I did notice the 12VDC was under, it was around 11.85VDC. Just curious what is a way to gage the min and max of given voltages? like a 5% rule or something? Thank you again for all the input
 
It depends on the circuit, but if I had 200mv ripple I would try bridging a capacitor across the supply line to see if that cures the symptom.
 
Status
Not open for further replies.

Similar threads

  • Question
Vizio TV e701i-a3 No pic but backlight
Replies
13
Views
2K
Serge 125
R
  • Question
Active monitor - power up but no sound during a few minutes
Replies
9
Views
2K
Nigel Goodwin
S
  • Question
Sony Trinitron Picture Scrambled When Powered On
2
Replies
37
Views
3K
scottradio
S
A
  • Question
Repairing tile no sound output
Replies
5
Views
906
amateur_24
A
N
  • Question
JBL clip 3 starts but no sound
Replies
0
Views
1K
NoePerez
N
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…