All I get is a black screen when plugged in and power on. Power board is DPS-260JP. Board doesn't seem to have any burnt parts or bulging caps. Something I noticed was that when I wiggle the wider plug around, the back light would flash for split seconds. I would slowly move the plug around stop as soon as the back light comes on. The back light would then stay on. I notice this blue LED lights up for couple seconds then it fades away and the back light turns off. Any suggestions.
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Re: Vizio sv420m black screen
Once you get the b/l on does it then stay on and the TV runs fine?System: HP xw6600 Workstation, 650W PSU | 2x Intel Xeon Quad E5440 @2.83GHz | 8x 1GB FB-DDR2 @ 667MHz | Kingston/Intel X25-M 160GB SSD | 2x 1TB Spinpoint F3, RAID0 | 1x 1TB Spinpoint F3, backup | ATI FireGL V7700 512MB | Sony Optiarc DVD +/-RW | Win 7 Ultimate x64 | 2x Dell UltraSharp U2410f | Dell E248WFP -
Re: Vizio sv420m black screen
No. Once I get b/l to stay on, I see a blue LED on the board that is lit up. It will light up for like 5 sec and then fade away. After it fades off, the b/l goes out.Comment
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Re: Vizio sv420m black screen
was there ever a fix found for this issue?The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS
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Re: Vizio sv420m black screen
I sure sounds like soldering, plug/cable or other intermittent connection issues were the trouble here.Comment
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Re: Vizio sv420m black screen
If you have sound then problem is usually the backlight inverter, replace.Comment
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Re: Vizio sv420m black screen
I asked before about this set beacause there was one on CL that I was negotiating on. I finally picked it up today.
Here is the issue:
Not turning on at all. - Sounds easy enough
Front Vizio symbol is amber and does not change with power button.
Caps are visually ok and no burnt components on the board. I see a smaller red rectangular fuse on the power board. I have to take the board out to check this one but for now here is the rest of my checks.
117VAC across main fuse - OK
5VSB from power board to mainboard - OK
Two fuses on mainboard checked - OK
PS-on = 0.017 VDC before, during, and after power button is pressed.
It's been a while for me, it's gonna be fun getting back into this.The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS
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Re: Vizio sv420m black screen
Has it got the infamous U33?Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: Vizio sv420m black screen
It's layout is different than the usual vizio vw42L or vo42L. The power board holds the inverter and there is a mainboard and Tconn. It has some LDO regs on it. Two have 5v inputs and 3.3vdc on one, 3v on the other. There is a third one that doesnt have any voltage to it. I'm thinking that this one needs power from once it's turned on.
I have to take some pictures right now and I'll post it.The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS
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Re: Vizio sv420m black screen
I took some readings off of the regulators.
U2 = 3.3 out - 5 in
U3 = 3.26 out - 5 in
U4 = 1.25 out - 3.3 in
U5 = 3.3 out - 5 in
U6 = 0 out - 0 in
U7 = 3.3 out - 5 in
If remembering correctly, that ps-on should have something right? Not zero volts.Attached FilesThe strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS
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Re: Vizio sv420m black screen
I find it a lot safer if you just do a simple resistance test on the main fuse versus measuring up to 120V AC (or 240V AC in other countries). Both achieve the same result.Originally posted by Dgtech View Post--- begin sig file ---
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Re: Vizio sv420m black screen
Something is obviously wrong with U6. U6 looks like an adjustable regulator (as shown in picture). That means the outpin pin should be adj + 1.25V. In this case, if adj pin is 0.0V, then output should be 0.0 + 1.25 or 1.25V.Originally posted by Dgtech View Post
PS_ON is generated by the main board to tell the power supply to turn "on". It is usually 3V or higher.
PS. I can't believe how many Vizios are failing because of bad voltage regulators.--- begin sig file ---
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Re: Vizio sv420m black screen
1) BTW, when I post instructions for people, I always ask for the measurement of all 3 pins and the part numbers. Getting the measurements of all the pins is important if it is an adjustable voltage regulator. Getting the part number is important so we know what the expected output voltage should be.Originally posted by Dgtech View Post
For example,
U100
AS1117-33
pin 1 = 0.0
pin 2 = 3.3
pin 3 = 5.0
2) After looking at your results again, U3 is suspect too. If it is a fixed 3.3V output regulator, it is barely within spec assuming a +/- 1%.
3.3 x 0.99 = 3.267V
3.3 x 1.01 = 3.333V
3) If U3 is an ajustable regulator and the adj pin is 2.00V, then 2.00 + 1.25 = 3.25V.Last edited by retiredcaps; 07-06-2012, 02:53 PM.--- begin sig file ---
If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.
We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.
Please do not post inline and offsite as they slow down the loading of pages.
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Re: Vizio sv420m black screen
Also, a very slightly low reading is sometimes indicative of an oscillating regulator. If you have a scope, check the Vout pin.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: Vizio sv420m black screen
Any chance of a service manual??The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS
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Re: Vizio sv420m black screen
Service manuals, Vizio will never give out complete info.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 sv420m black screen
Here are more of the readings:
U2 (1117) IN 5.2 OUT 3.3 ADJ 2.07
U4 (1117) IN 3.26 OUT 1.25 ADJ 0
U6 (1117) IN 0 OUT 0 ADJ 0
U7 (1117) IN 5.18 OUT 3.25 ADJ 2.01
U3 and U5 are a different type of regulators marked (L471 G1084)
U3 = IN 3.16 OUT 1.24 GND
U5 = IN 3.14 OUT 1.25 GND
5VSB = 5.22 from power board
12V = 0 from power board
I'm thinking that the 12V isnt present until the unit is on - out of standby.
I dont know if that is the same thing with U6's voltages.
I'm just not sure.The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS
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Re: Vizio sv420m black screen
On the service manual troubleshooting flow chart, they say to check pin 2 of U6 for 8VDC however the 12V to this board is not active until the unit comes out of standby. Then, I'd think, the 12V gets regulated down to 8V.The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS
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Re: Vizio sv420m black screen
I'm thinking about pulling U6 for the hell of it, just to see what will be on the input pad when it's off the board. If there is no input voltage, U6 is not to blame - not yet at least. If U6 is shorted and grounding out it's input voltage then there should be the correct input voltage there on the input pin. That is... again....if this voltage is supposed to be present in standby.The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS
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Re: Vizio sv420m black screen
No need to desolder U6, just test for shorts on all 3 pin combinations in circuit.Originally posted by Dgtech View Post
Does 12V come up if the power board is disconnected from the main board?--- begin sig file ---
If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.
We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.
Please do not post inline and offsite as they slow down the loading of pages.
--- end sig file ---Comment
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