Hello folks,
I've been reading through threads on the Vizio vt420m TV and general troubleshooting and would like some input on what I've found so far. In checking the voltage regulators on the main board I think I've found two that are not putting out correctly. One VR does appear to be correct. Should I just try replacing the two that seem bad or should I check other components given the current level of functionality that the set has (read below)?
I can power on the set either from the remote or from the side controls. It will power up and show the Vizio logo on the screen so back-light is definitely on. I can also power off the set either from the remote or from the side controls. I've tried several of the reset procedures; holding buttons, powering on/off and unplugging (even overnight). None of those changes the current behavior.
I've looked online for replacement main boards but it would seem that for this model they are all gone. I did find one place that was mentioned in a YouTube video that will let you send in your board and they will either repair it or send you a used replacement and I might try that route if I can't find and fix the issue myself.
Please let me know if any further information would be helpful or other pictures/angles are needed. The pictures attached are not great but do show U701, U702 and U103 on the main board and I think U702 and U103 might be bad.
EDIT: FYI, looking at the boards does not seem to show any blown caps or obvious brown/black marks that might indicate further issues.
EDIT2: I did try cooling the VRs with compress air to see if the TV would fully turn on but no joy at U701 or U702. Did not try U103.
U701 - Not sure
0
9.03
11.89
U702 - Bad?
0
1.88
3.28
U103 - Bad?
0
4.01
4.98
Thanks folks!
Chris
I've been reading through threads on the Vizio vt420m TV and general troubleshooting and would like some input on what I've found so far. In checking the voltage regulators on the main board I think I've found two that are not putting out correctly. One VR does appear to be correct. Should I just try replacing the two that seem bad or should I check other components given the current level of functionality that the set has (read below)?
I can power on the set either from the remote or from the side controls. It will power up and show the Vizio logo on the screen so back-light is definitely on. I can also power off the set either from the remote or from the side controls. I've tried several of the reset procedures; holding buttons, powering on/off and unplugging (even overnight). None of those changes the current behavior.
I've looked online for replacement main boards but it would seem that for this model they are all gone. I did find one place that was mentioned in a YouTube video that will let you send in your board and they will either repair it or send you a used replacement and I might try that route if I can't find and fix the issue myself.
Please let me know if any further information would be helpful or other pictures/angles are needed. The pictures attached are not great but do show U701, U702 and U103 on the main board and I think U702 and U103 might be bad.
EDIT: FYI, looking at the boards does not seem to show any blown caps or obvious brown/black marks that might indicate further issues.
EDIT2: I did try cooling the VRs with compress air to see if the TV would fully turn on but no joy at U701 or U702. Did not try U103.
U701 - Not sure
0
9.03
11.89
U702 - Bad?
0
1.88
3.28
U103 - Bad?
0
4.01
4.98
Thanks folks!
Chris
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