ViewSonic vs11531 white screen

[idealmonster]

I need help!!! I have this viewsonic monitor that turns on but only displays a white screen. I replaced the logic board( the one with the video ins.)nothing.
I have checked the other board(the one that is on the lcd ) for bad caps or blown fuses...nothing that I can see. all the cables seem to be fine. what am I missing . I have scoured the forums many a days and decided a post might be helpful. Please help!


jenn

[Rtech]

Re: ViewSonic vs11531 white screen

Does the Power led change colour when you apply a signal from the Computer ??

[selldoor]

Re: ViewSonic vs11531 white screen

Are you saying you cant find any fuses or none that are blown
Was the replacement logic board EXACTLY the same part number and revision.
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/attach...7&d=1280167246

https://www.badcaps.net/forum/attach...6&d=1280167246

https://www.badcaps.net/forum/attach...4&d=1280167246

It will be useful if you can say a bit about yourself - skills tools etc.

[idealmonster]

Re: ViewSonic vs11531 white screen

I haven't really hooked it up to a computer because it has hdmi and rca's in so when I have either of those hooked up still nothing but white screen and the power led stays blue. I do hear an almost high pitched whining when the white screen comes on. I found all the fuses but none SEEM to be "open" or blown. I replaced the OLD logic board part #70-y2832500 (vx2835 r3.1) with new logic board part # 70-y2832600 (vx2835 r3.1) I see the difference but I was assured it "should work"
however if the "old logic board is in it does the same exact thing..so the problem must be elsewhere????
As my skill level I must say if there was ever a newbie that would be me. I just really appreciate that things can be fixed before being discarded. I'm very intrigued at all of you that do this stuff and only wish to learn more.
I will work on getting some pics of my boards asap.
thanks

[budm]

Re: ViewSonic vs11531 white screen

There should be a small surface mounted fuse on the integrated LCD panel/T-CON assembly. There should be either 5V or 12V on both ends of that fuse.

[idealmonster]

Re: ViewSonic vs11531 white screen

The fuse on the t-con board fuse label f-400 has no continuity no reading so it is bad..???? I will try to replace. Where is the best place to get these sm fuses??? I tried radio shack but no nothing. I would really like to get one asap as im very excited to see this monitor work!! The letter on the fuse reads N. I would have to replace it with the same exact one or as long as it has the same volts????
gosh I feel like such a newbie!

[budm]

Re: ViewSonic vs11531 white screen

Before puting in the new fuse, you need to use Ohm meter to check the resistance on each end of the fuse with ref to ground to make usre the fuse is not feeding short circuits, otherwise you will blow up the new fuse.

[idealmonster]

Re: ViewSonic vs11531 white screen

thanks budm.. as I said before im a totally newbie . I touched the mulitmeter black onside of fuse and red on the other side.. no reading..
I grounded the black and touch the right side of fuse reading was nothing and the left side was 1.09 this was having my meter set to 2k ohm... am I taking the readings right.? sorry Im totally a kindergarden that needs their hand held... please advise on the correct way to test...thanks again ...

[selldoor]

Re: ViewSonic vs11531 white screen

That looks ok apart from the fuse having two left sides?
N seems to often indicate 2 amp fuse. You can buy from digikey or mouser or ebay but are often expensive locally or take a long time from china.

For testing a lot of people use a Pico 2a fuse
http://www.digikey.com/product-detai...64TR-ND/700732
or sometimes solder a fuse holder to the existing fuse ends and use any 2a fuse that will fit the holder. I have even seen an auto fuse being soldered in but you need to be careful insulating it - one time someone did that and the fuse dropped off onto the board with dire results.

Whatever you decide you do not need to remove the old fuse first - just solder on top
First though measure the old one as you need to get one the same physical size length and width

[budm]

Re: ViewSonic vs11531 white screen

I myself use through hole PICO II fuse, juts have to bend the leg or trace out the copper traces for easy solder points.

[idealmonster]

Re: ViewSonic vs11531 white screen

ok so I guess ill order some of these and see what happens.
Budm any chance you have a pic of your soldered down pico fuse??? ...just for reference. Im not 100 % on my soldering and things that have pictures r always easier!!!
well wish me luck once I get the fuse solder in I will let u know the outcome..
once again thanku all
your brilliant

[budm]

Re: ViewSonic vs11531 white screen

http://s807.beta.photobucket.com/use...tml?sort=6&o=2

PICO fuse:
http://s807.beta.photobucket.com/use...y%20Littlefuse

You can also solder small wires to each end of the old fuse (no need to remove the old fuse), then solder the wire to the PICO fuse with the legs trimmed short enough to solder the wires to and tape it up.

[idealmonster]

Re: ViewSonic vs11531 white screen

thankyou budm you have been very helpful! Very helpful pics too! cant wait to try this out. As a newbie I was wondering when u say "You can also solder small wires to each end of the old fuse" what kindof wire ?why couldn't I just solder the legs of the new pico fuse directly on top of the sm fuse?? Ive been watching a lot of youtube turtorials..my brain hurts.. haha before im done I could be a novice ...

[budm]

Re: ViewSonic vs11531 white screen

If the fuse is mouted on the side of the board that will face the LCD chassis, it may not allow the board to lay down flat due to the body of the PICO fuse.

[idealmonster]

Re: ViewSonic vs11531 white screen

Well I put the new fuse in and it did the same exact thing.. white screen with blue power light. It kept blowing the fuse... time for a new t-con card???? part HannStar 70.72600.A14 T-Con Board.
Gosh and I so wanted this to work, guess ill still just be a newbie

[idealmonster]

Re: ViewSonic vs11531 white screen

So an update my new t-con came in today popped it in a volia its working!
I just wanted to thank all those who replied to my orginal post and especially budm for his help! I have a new found interest in circuit boards lol

[budm]

Re: ViewSonic vs11531 white screen

Glad you got it fixed!

[momaka]

Re: ViewSonic vs11531 white screen

Nice work!

The old t-con may still be repairable too if you care. The problem is usually a single multilayer ceramic cap (those tan rectangular components) going short circuit in the main power supply section of the t-con, which is what causes the fuse to blow. It's a bit tricky to find which ceramic cap is the shorted one since often there will be many others in parallel with it so they will all appear shorted. But it's do-able. I had 2 monitors with a white screen issue and no one thought me how to fix them. All it took me to figure it out was a multimeter, a very basic theory on electronic components (how they could/should measure on a multimeter in circuit) and lots of time and patience. If you provide good pictures, I may be able to help you troubleshoot the old t-con.