Viewsonic LCD VA1703wb : opened one va1703wb model viewsonic monitor for the problem 'backlight turns off in 2 seconds'. Replaced all the capacitors still problem persists. It uses MP1008ES in the inverter board. When I downloaded the diagram it says the inverter contains OZ series chip on it!! Can anyone suggest where is the current sensing / ovpt for MP1008ES chip and how can I disable the ovpt??
-
-
Re: Viewsonic LCD VA1703wb
So does it use the MP10008ES PWM IC or the OZ XXXX BY O2 MICRO?
Do you have the diagram?
Does your board look like this?
http://s807.photobucket.com/albums/y...ic%20VA1703WB/Last edited by budm; 12-01-2012, 10:41 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=24809 -
Re: Viewsonic LCD VA1703wb
Thanks budm..it uses MP1008ES .. I couldnot get the diagram!! The board is not looking like this (*ttp://s807.photobucket.com/albums/y...ic%20VA1703WB/) as shown in thatComment
-
Re: Viewsonic LCD VA1703wb
Ft pin4, when it is HIGH it will activate the shutdown. So monitor that pin with the 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
-
Re: Viewsonic LCD VA1703wb
oh thanks again budm... Is there a chance to eliminate the current sensing?? I have confirmed the lamps are ok by connecting different lamps.Comment
-
Re: Viewsonic LCD VA1703wb
So you connect the good set of lamps to this board and they stay on? I am a little confused.
"I have confirmed the lamps are ok by connecting different lamps."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
-
Re: Viewsonic LCD VA1703wb
Hmmm .....
Pardon me for butting in ...
It's there for a good reason. Two minuses doesn't make a plus ... Best to figure out why current sensing cuts out.
I'm scratching me head as how can this deduction be possible ....Comment
-
Re: Viewsonic LCD VA1703wb
I think we need to see pictures of your boards
Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.
Please do not post inline and offsite as they slow down the loading of pages.
Examples of what is needed
https://www.badcaps.net/forum/attachm...1&d=1290283049
https://www.badcaps.net/forum/attachm...7&d=1280167246Please upload pictures using attachment function when ask for help on the repair
http://www.badcaps.net/forum/showthread.php?t=39740Comment
-
Re: Viewsonic LCD VA1703wb
thanks budm... I think i have confused you. Came to say even when a good set of lamps are connected to the board, problem persists. I came to say it is NOT problem with lamps. It should be problem with the inverter board. Will upload photos little laterComment
-
Hello, I came here after finding some similar questions asked on other monitors and hope someone here can help me get an ancient Viewsonic VP230mp (23" 4:3 LCD) back to working condition.
First a little background, I have a background in computer and electrical engineering, and I'm smart enough to know I know nothing about LCD displays and how they work. For this topic I'm as green as they come.
When the display is turned on the viewsonic logo displays in the uppper left for 2 seconds then the screen goes black, the power LED is green (on) and when a computer is connected... -
I just got this tv today and it appeared to have no backlight on. After taking off the rear cover and checking again in the dark I can see that MAYBE one quadrant is lit.. But still it's quite dim. I was going to check the LEDs with my tester, and I found LED 1 and LED 2 + pins on the wire from the inverter, but I couldn't identify a ground. Nonetheless I tried using a mounting screw on the inverter board and also the chassis as ground but regardless my tester reads 300 which is what it reads when there is no voltage draw.
I don't know how exactly to test the inverter itself. Is it... -
I have a tripp-lite aspint 3636vr inverter charger which blow some of mosfet transistors. I replaced them repaired also the driver circuit and tested but the mosfets burn again.
It work very well as inverter and also as charger if I let the rear switch in auto mode (inverter) and charger only(charging) but in auto when I connect the feed line 220V AC first time it pass ok to line and start charging the batteries but when I remove the feed line it pass to inverter mode and if I do it again the second time when passing from charging to inverter the Main transformer start making a...03-06-2023, 07:07 AM -
For some reason I'm just not going to let this 19" TV defeat me. I guess because I have a schematic to work from I feel like I'm oh so close.
History- while adding a turn-on circuit I let a small screw roll under the power board. Worked through all of that circuitry, probably replacing a MOSFET and PWM controller that were not bad but I was following the service manual. Finally figured out that the power supply is in working order when the inverter section (for the backlights) is disconnected. When the +12 supply to the inverter is disconnected the +12 and +5 will come up... -
hello everyone, I'm looking for the wiring diagram of this led monitor.
the model is DHI-LM19-L200, but I think that any other diagram of a DAHUA monitor could be equivalent.
I really hope that among you someone can help me to repair this monitor, the screen is black, it doesn't seem like a backlight problem.
I see the presence of 12 volts, 5 volts, but without a diagram the repair is very difficult.
thanks to those who will answer12-10-2024, 04:37 PM
Comment