Strange problem with Acer V193W

[srbax]

Hello,

This monitor has strange problem to me.
When computer is booting there is a picture of start up and after that is gone.
When computer is up I have to press power button twice and I get the picture.
Picture is not all over the screen and lines are not straight and looks like it's floating.
I did some pictures of that.
When I change frequency at it's maximum 75 Hz, picture is gone.
This monitor was checked from one guy who is fixing tv, monitors, audio equipments etc and he told me that he replaced some capacitors and checked other components as well.
He suspect on processor and main board.
I want your opinion and help to solve this problem.

[retiredcaps]

Re: Strange problem with Acer V193W

Check the voltage regulator on the main/logic board.

[srbax]

Re: Strange problem with Acer V193W

I did it.
It has folloving values:
pin1=0
pin2=3.28
pin3=4.88
pin4=3.28
Could it be oscillator problem?

[selldoor]

Re: Strange problem with Acer V193W

Was the measurement taken when the fault was on screen and does the voltage stay steady at that.
Can you tell which caps were replaced and what make/series are they.
There is probably another long board on the back of the panel can you post picture of that . to get it big enough do it in 3 sections.
There may be a flat ribbon cable to this board - if it is removable take it out and clean the contacts then replace and try.

[srbax]

Re: Strange problem with Acer V193W

I made it to work steady at resolution 1024x768 and 60 Hz. It won't work at 75 Hz.
Picture was nice and clear.
It's native resolution is 1440x900 and 75 Hz and it won't work as I mentioned before.
When it's working voltages are:
pin1=0.012
pin2=3.26
pin3=5.012
pin4=3.26
I'm not sure which caps are replaced. I think that only big one is not replaced and I can't see letters on it.
I made some pictures of caps. I hope they are good.

[selldoor]

Re: Strange problem with Acer V193W

Wow! that is a horrible set of caps!! I dont think he has changed any or if he has he has changed them for previously used or old ones - its lucky its working at all.
My suggestion would be to make a list of all the caps on the board with a view to changing some/ most or all of them. Ugghh.

Right as you will have seen there is another voltage regulator on the panel board.
Can you test that as with the other one.

[Pentium4]

Re: Strange problem with Acer V193W

CapCon?! I bet the main cap is a Lelon. I'd replace all of them except the big cap. That JH cap is only 85C, could be dried out...

[srbax]

Re: Strange problem with Acer V193W

I've tested voltage regulator on panel board:
pin1=0
pin2=3.31
pin3=4.95
pin4=3.31
Now I worry if those caps has the right values.
Is it important for all of those caps to be with low ESR?
On main board all caps are Samxon. Should I replace them to? They look ok.

[selldoor]

Re: Strange problem with Acer V193W

Is it difficult /expensive to get good low esr caps in Serbia?
If so I would leave the main board for now and perhaps try replacing
just the medium sized caps on the power supply.

Have you another screen that will do 1440x900 at 75 I am just wondering if
the pc /video card can output at that?

[srbax]

Re: Strange problem with Acer V193W

Yes, it's difficult.
I have MSI 4850 video card and I'm using it on my Sony 40" tv in full hd.
Also I was connecting monitor on lap top with vga output to be sure that dvi to vga adapter is not a problem.
I'm using that adapter when I connecting monitor on my pc.
Lap top also has a good video card.

[srbax]

Re: Strange problem with Acer V193W

I bought new caps, Capcon,Capxon and something that I can't read
I will replace them all, not a problem.

[srbax]

Re: Strange problem with Acer V193W

I replaced all caps on ps board.
Nothing has changed.
Maybe I didn't mention, but even when I switch it to resolution 1024x768, I have to press power button 4 times to make it working.
Interesting is that power light is off when running normally and when picture is black it's amber.
Maybe it's normal for Acer monitors.
What now?

[Pentium4]

Re: Strange problem with Acer V193W

You recapped with CapXon?!

[srbax]

Re: Strange problem with Acer V193W

There is no better caps in Serbia.
Only things like Capxon, Capcon, Jamicon and maybe some other junk.
Very rarely Yageo.

[Pentium4]

Re: Strange problem with Acer V193W

I think Jamicon are better than CapXon. But they should work long enough for you to figure out the other issues.

[selldoor]

Re: Strange problem with Acer V193W

Hi - Hmm I have just been reading a thread with strating problem and led problem.
read this bit - not your set but maybe a dirty switch is part of the problem
https://www.badcaps.net/forum/showpo...&postcount=146

[selldoor]

Re: Strange problem with Acer V193W

Next as you have changed some caps can you re test the at the voltage regulators and can you also put the marking off the regulator with the results.
With it all connected up and working can you also test and post the voltages on the
connector at the top right of the power supply board list like this using what it says on the board for "should be"
Pin***Should be*****Is
1***** 15v*********14.91v

[srbax]

Re: Strange problem with Acer V193W

I've done testings.
Voltage regulator on main board:
pin1=0
pin2=3.29
pin3=5.09
pin4=3.29
AS1117L-33

Voltage regulator on screen panel:
pin1=0.06
pin2=3.38
pin3=5.08
pin4=3.38
50117K-F
when it's not working because of resolution there is some slight variation of voltages on both voltage regulators and on contacts below.

Something strange occurs.
With resolution 1024x768 and 60 Hz, wasn't good and it was working ok with it's native resolution and 75 Hz, but I had to power off/on monitor.
Voltages on output of PS board:
1. VCC5V 5.149V
2. VCC5V 5.149V
3. GND 0.03V
4. GND 0.03V
5. ON/OFF 3.25V
6. BRIGHTNESS 2.72V
7. VOLUME 0.085V
8. MUTE 3.21V
I was reading this post and maybe I have similar problem:
https://www.badcaps.net/forum/showth...ghlight=SCALER
Should I change some caps on logic board or all of them?

[selldoor]

Re: Strange problem with Acer V193W

It would be easy for me to say change them all but if your store is easy to get to and you can buy a few at a time perhaps buy 2 or 3 and try them on the part of the board that seems most connected to the screen cable socket.
( you have cleaned that thoroughly both ends and checked for bent /broken pins.)
If that doesnt change anything you could either buy another 3 or put the old ones back and try them in the places on the board
Sorry I have assumed all 6 are the same size if not that plan is sunk
perhaps buy 2 and so on.

P.S Voltages on the VRs are reasonable they are both 3.3v VRs

[srbax]

Re: Strange problem with Acer V193W

I changed all caps.
When I powered on monitor, it's behavior was the same as before.
After a while he began to behave differently.
Now lamps are working all the time, but there is no picture.
I even haven't "no signal" with disconnected signal cable.
All voltages are there.
When I was measuring voltages on logic board, I noticed that, when I was touching only one pin of oscillator, lamps started to blinking.
I tried to measure frequency of oscillator and I got very unstable values, from 5 to 50 Hz.
Is it possible to measure it like that and is it normal behavior.
What else can I check or do?