Hello everyone! This is my first thread on this kick butt site and I have to say 2 things up front.
First. This site rocks! After much searching I have learned quite a bit just searching arround on this forum. You guys are very informative!
Second. I apologieze for any typing mistakes. I am posting from my phone and everyone knows how that can go.
Now on to my perplexing issue.
I have a ViewSonic VT3745 LCD TV and for a few months now it doesn't want to power up most of the time...
When I try to turn the unit on, the standby light goes from orange to blue. Sometimes it stays blue but there is no picture, sound or any other sign that it is on other than the blue light. I am unable to power the unit down so I have to unplug it. After several attempts of turning the tv on (and having to unplug it with every attempt) the indicator light will go from orange to blue and then back to orange in about 5 seconds.... I can then try and power the unit on again with the same orange/blue/orange cycle. After about 10-100 attempts like this it will then turn on and display the viewsonic bird logo and work normally (blue light on and the screen lights up) untill I power it down. The next time I try to turn it on, it does the whole dang thing over again.... It's to the point where we just leave it on 24/7 and that drives me crazy because I don't like the idea of wasting the tv's life and running up my electrical bill....
Now being a mechanic of all trades and never leaving well enough alone, I have been determined to fix this unit. After a lot of searching I have been unable to find anything out about this issue with my TV. Searching on here and elsewhere all suggest to look at the simple stuff first (like cords being properly plugged in) and then work up from there... The next thing that I have seen a lot of people recommend to check for blown Caps or other components... After extensive use of the Mk.I eyeball and a good flashlight, I haven't been able to spot a single char/dark spot or bulged/leaking cap. I have looked at the powersupply and the logic board... There is also another board that I presume runs the ccfl lamps and that looks good as well. So after more digging I see that some caps can go bad but still look good and without a esr tester, it is hard to determine if the caps are bad without the aforementioned symptoms.
So being handy with a soldering gun and having an abundance of caps arround my house (coupled with my OCD of wanting to fix stuff), I replaced most all the caps on my powersupply. I didn't have a 50v 22uf unit so I skipped that one. I also didn't have the giant one that was on the board as well... All the others have comparitable caps installed (same voltage, uf, and 105c ). Now with all that out of the way, I put the unit back together and it still exhibits the no power up problem.
I figured because the unit wouldn't power up all the way and from all the knowledge on this site, it wouldn't hurt to just replace the caps for the heck of it anyways to cut that possibility out. When I volt tick the PSU, I get 4.99v dc on the standby circuit, 11.99VDC out of the 12v circuit when powered on but then when the tv goes back to stanby (orange light) the voltage gradually falls to 0 in the course of 10-20 seconds... The 24VDC to the ccfl circuit also shows fine untill the unit goes to stanby... It's like all the voltages are what they should be but something faults and shuts off the whole TV. This is with the old caps and the new ones too... Nothing changed when I put the caps in....
Thinking back on my testing, I forgot to see what the voltages were when it was stuck on the blue light (on but not "on"). I will do that tomorrow after I get some much needed sleep.
These things I have done:
Turned the unit off and back on.
Replaced most of the caps on the PSU.
Checked the voltages when the TV is powering up and when it is on and actually running.
Checked the screen with the flashlight trick to see if the ccfl's are bad.
Looked at each circuit board for any obviousness signs of problems like bulged caps or char marks.
Unplugged and reseated every cord.
Checked the fuses (2 I believe or was it one.....)
The powersupply is a FSP163-3F01
Here is a link to a photo of that unit (not mine, but it is identical for reference)
http://assets.shopjimmy.com/media/ca...3-3f01-top.jpg
Now I am at a loss and want to see if y'all have any suggestions or have encountered an issue like this before... Any help/pointers would be much apreciated!
Thank you all in advance for everything! before... Any help/pointers would be much apreciated!
Thank you all in advance for everything!
First. This site rocks! After much searching I have learned quite a bit just searching arround on this forum. You guys are very informative!
Second. I apologieze for any typing mistakes. I am posting from my phone and everyone knows how that can go.
Now on to my perplexing issue.
I have a ViewSonic VT3745 LCD TV and for a few months now it doesn't want to power up most of the time...
When I try to turn the unit on, the standby light goes from orange to blue. Sometimes it stays blue but there is no picture, sound or any other sign that it is on other than the blue light. I am unable to power the unit down so I have to unplug it. After several attempts of turning the tv on (and having to unplug it with every attempt) the indicator light will go from orange to blue and then back to orange in about 5 seconds.... I can then try and power the unit on again with the same orange/blue/orange cycle. After about 10-100 attempts like this it will then turn on and display the viewsonic bird logo and work normally (blue light on and the screen lights up) untill I power it down. The next time I try to turn it on, it does the whole dang thing over again.... It's to the point where we just leave it on 24/7 and that drives me crazy because I don't like the idea of wasting the tv's life and running up my electrical bill....
Now being a mechanic of all trades and never leaving well enough alone, I have been determined to fix this unit. After a lot of searching I have been unable to find anything out about this issue with my TV. Searching on here and elsewhere all suggest to look at the simple stuff first (like cords being properly plugged in) and then work up from there... The next thing that I have seen a lot of people recommend to check for blown Caps or other components... After extensive use of the Mk.I eyeball and a good flashlight, I haven't been able to spot a single char/dark spot or bulged/leaking cap. I have looked at the powersupply and the logic board... There is also another board that I presume runs the ccfl lamps and that looks good as well. So after more digging I see that some caps can go bad but still look good and without a esr tester, it is hard to determine if the caps are bad without the aforementioned symptoms.
So being handy with a soldering gun and having an abundance of caps arround my house (coupled with my OCD of wanting to fix stuff), I replaced most all the caps on my powersupply. I didn't have a 50v 22uf unit so I skipped that one. I also didn't have the giant one that was on the board as well... All the others have comparitable caps installed (same voltage, uf, and 105c ). Now with all that out of the way, I put the unit back together and it still exhibits the no power up problem.
I figured because the unit wouldn't power up all the way and from all the knowledge on this site, it wouldn't hurt to just replace the caps for the heck of it anyways to cut that possibility out. When I volt tick the PSU, I get 4.99v dc on the standby circuit, 11.99VDC out of the 12v circuit when powered on but then when the tv goes back to stanby (orange light) the voltage gradually falls to 0 in the course of 10-20 seconds... The 24VDC to the ccfl circuit also shows fine untill the unit goes to stanby... It's like all the voltages are what they should be but something faults and shuts off the whole TV. This is with the old caps and the new ones too... Nothing changed when I put the caps in....
Thinking back on my testing, I forgot to see what the voltages were when it was stuck on the blue light (on but not "on"). I will do that tomorrow after I get some much needed sleep.
These things I have done:
Turned the unit off and back on.
Replaced most of the caps on the PSU.
Checked the voltages when the TV is powering up and when it is on and actually running.
Checked the screen with the flashlight trick to see if the ccfl's are bad.
Looked at each circuit board for any obviousness signs of problems like bulged caps or char marks.
Unplugged and reseated every cord.
Checked the fuses (2 I believe or was it one.....)
The powersupply is a FSP163-3F01
Here is a link to a photo of that unit (not mine, but it is identical for reference)
http://assets.shopjimmy.com/media/ca...3-3f01-top.jpg
Now I am at a loss and want to see if y'all have any suggestions or have encountered an issue like this before... Any help/pointers would be much apreciated!
Thank you all in advance for everything! before... Any help/pointers would be much apreciated!
Thank you all in advance for everything!
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