This tv only has two boards the Power Supply and the Control or Mainboard. (My volt meter died so will be testing voltages later) I did conduct a thorough visual examinations of the boards and they appear to be fine. I checked continuity on all fuses and they tested good. The Vizio LOGO on the front of the television does not come on while plugged in which suggests to me no stand by power.
Vizio M550SV No Power/Lightning Strike
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Re: Vizio M550SV No Power/Lightning Strike
if you have a digital multimeter, check for expected voltages on connectors/cables going to the other board, see the legend/label, next to the connectors? check stby first, report any that are not as marked on label, as always be careful working with power supply, HIGH VOLTAGE, on primary side can be deadly. -
Re: Vizio M550SV No Power/Lightning Strike
Check the main AC fuse (white fuse with red band), if it's OK then check the DC Voltage right at the two legs of the main filter caps (68uF 450VDC) to see if it has 160VDC (you must have this voltage before going any further), be real careful not to slip the probes and do not touch anything with your hands.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: Vizio M550SV No Power/Lightning Strike
looks like theres another fuse there by the filter caps too.Comment
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Re: Vizio M550SV No Power/Lightning Strike
I believe that fuse is connected to the output of the PFC Voltage circuit to feed the man power supply section.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: Vizio M550SV No Power/Lightning Strike
Continuity on both of the fuses checks out as good. I am getting 6 volts on in of DC fuse the one by the power connector. This is when the set is plugged in. Of course when power is pressed absolutely nothing happens. All standby numbers look fine.Comment
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Re: Vizio M550SV No Power/Lightning Strike
ok, did you check all expected voltages on power supply?, should be labels by the connectors.Comment
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Re: Vizio M550SV No Power/Lightning Strike
Check the main AC fuse (white fuse with red band), if it's OK then check the DC Voltage right at the two legs of the main filter caps (68uF 450VDC) to see if it has 160VDC (you must have this voltage before going any further), be real careful not to slip the probes and do not touch anything with your hands.Comment
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Re: Vizio M550SV No Power/Lightning Strike
Where did you put the black probe of your meter?Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: Vizio M550SV No Power/Lightning Strike
when checking the connectors black probe goes to ground ether chassis or a screw, etc.Comment
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Re: Vizio M550SV No Power/Lightning Strike
I keep the black probe on the ground wire that goes to the chassis by the main power plugin. There are two caps side by side which cap are you referring to? At any rate on the right leg of each of those caps I get the same reading for 67.1Last edited by gideon277; 02-04-2015, 11:08 AM.Comment
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Re: Vizio M550SV No Power/Lightning Strike
When you make the Voltage measurement in the primary (hot) side of the circuit, you must use the negative leg of the main filter cap and the GND ref. for your meter.
When making Voltage measurement in the isolated secondary side of the circuit, you can use chassis as the GND ref, because the Isolated secondary side power supply circuit GND is tied to the chassis.
"At any rate on the right leg of each of those caps I get the same reading for 67.1" That is why you get that wrong reading of 67V.
POST #3: "if it's OK then check the DC Voltage right at the two legs of the main filter caps (68uF 450VDC) to see if it has 160VDC" That is why I gave the instruction to measure the Voltage RIGHT AT THE TWO LEGS OF THE CAP.
Please follow the instruction carefully since wrong readings will make it very hard for us to troubleshoot the problems.Last edited by budm; 02-04-2015, 12:29 PM.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Comment
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Re: Vizio M550SV No Power/Lightning Strike
"right at the two legs of the main filter caps (68uF 450VDC)"
I can see that this is not going to be easy for me after 12 posts.Last edited by budm; 02-04-2015, 08:31 PM.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: Vizio M550SV No Power/Lightning Strike
That does not look right, disconnect the cables between the main board and the power supply board and recheck that Voltage on the cap again, it should have only around 160VDC.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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