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Old 06-24-2014, 03:36 AM   #641
gordesky1
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Default Re: Hanns-G HG281D, LCD Monitor no power

Hmm so far the brightness problem is gone after taking it apart, It now lets me change everything with out a problem maybe it was a dirty connection between the buttons.

But i still have those very hard to see dots pretty much they run in vertical down the screen which they are blinking and moving. mostly ony on dark colors like gray.

So far its not turning off either.

would this still be related to the caps and not the t-con board?

But will see if i can replace the caps.
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Old 06-24-2014, 03:42 AM   #642
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Default Re: Hanns-G HG281D, LCD Monitor no power

As you can see they will probably need replacing eventually, bad caps can cause more expensive damage if left.
It could be the tcon you could try cleaning the lvds cable contacts and reseating it.
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Old 06-24-2014, 03:49 AM   #643
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Default Re: Hanns-G HG281D, LCD Monitor no power

just did another test, I went and got the hair dryer and when blowing hot air on it nothing changed, So i tried the cool air function, And after about 10 to 20secs the screen turn off and on and it started to turn off and on really fast like every 2secs.

This is when blowing on the power supply and main board metal plate that covers it.

I herd if the caps are bad hot or cold air will let you know if it is a bad cap. Is that true?
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Old 06-24-2014, 04:06 AM   #644
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Default Re: Hanns-G HG281D, LCD Monitor no power

believe it or not,
caps work slightly better when warm.

you can get a worn out cap, heat it and it will look good on a tester - cool it down and it's fucked again.
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Old 06-24-2014, 04:11 AM   #645
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Default Re: Hanns-G HG281D, LCD Monitor no power

Yep so far it seems like it is the caps, it stays on longer when i heat it up, Than when i put cold air on it, It goes on and off faster.

So will replace the caps as post 629 when i get the chance Will put the monitor back in the box till than cause i don't want to damage it anymore than it is.
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Old 06-24-2014, 09:14 AM   #646
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Default Re: Hanns-G HG281D, LCD Monitor no power

I just repaired one of these and the 2 caps. that were causing my power supply problem were C603 and C606 , they both looked ok and even the capacity when checked was not that bad.
Sometimes the monitor would come on, sometimes not and the standby +5 was around 4.6 volts and pulsing when looked at with the scope.
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Last edited by R_J; 06-24-2014 at 09:17 AM..
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Old 06-26-2014, 09:20 AM   #647
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Default Re: Hanns-G HG281D, LCD Monitor no power

I just replaced every cap on the power supply board, and c80 and c83 on the main board, and when I turn on the monitor, light is blue, i see a dull flash of white, then nothing... Any ideas?
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Old 06-26-2014, 09:32 AM   #648
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Default Re: Hanns-G HG281D, LCD Monitor no power

Quote:
Originally Posted by mack505 View Post
I just replaced every cap on the power supply board, and c80 and c83 on the main board, and when I turn on the monitor, light is blue, i see a dull flash of white, then nothing... Any ideas?
Are we supposed to just guess what it did before you replaced the caps.
Have you read the thread done any tests made any notes taken any pictures.
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Old 06-26-2014, 09:45 AM   #649
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Default Re: Hanns-G HG281D, LCD Monitor no power

Quote:
Originally Posted by selldoor View Post
Are we supposed to just guess what it did before you replaced the caps.
Have you read the thread done any tests made any notes taken any pictures.
Thanks Selldoor, the monitor started flickering intermittently about every 10 min or so for about 30 sec. It did this for a week or so until it just went black.

After reading several posts and looking at the pics, I replaced every cap on the power supply board, except the largest one, and replaced the 3 470uf/16V (c99, c98, c103) and c80 and c83 on the main board.

I didn't take pics or vid of the symptoms before I replaced the caps, unfortunately.
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Old 06-26-2014, 11:01 AM   #650
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Default Re: Hanns-G HG281D, LCD Monitor no power

There is more than one type of power supply in these sets - what is the number/revision/date
on yours. Does the power light stay blue when the screen turns black. When connected to a pc displaying a known picture cany you see it - it will be very dim - shining a flashlight
at an angle may help.
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Old 06-26-2014, 01:01 PM   #651
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Default Re: Hanns-G HG281D, LCD Monitor no power

Quote:
Originally Posted by selldoor View Post
There is more than one type of power supply in these sets - what is the number/revision/date
on yours. Does the power light stay blue when the screen turns black. When connected to a pc displaying a known picture cany you see it - it will be very dim - shining a flashlight
at an angle may help.
The power supply is a PSM-217-404-H-R. The monitor says Apr 2008 on it.

The blue power light does stay blue when the screen turns black. I will reconnect it to see if I can see a picture with a flashlight.
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Old 06-26-2014, 02:22 PM   #652
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Default Re: Hanns-G HG281D, LCD Monitor no power

Quote:
Originally Posted by mack505 View Post
The power supply is a PSM-217-404-H-R. The monitor says Apr 2008 on it.

The blue power light does stay blue when the screen turns black. I will reconnect it to see if I can see a picture with a flashlight.
When I power it up, the blue light comes on, there's a faint white flash on the screen, then black. The blue light stays on the whole time, but I see no faint picture with a flashlight.
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Old 06-26-2014, 02:49 PM   #653
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Default Re: Hanns-G HG281D, LCD Monitor no power

Quote:
Originally Posted by mack505 View Post
When I power it up, the blue light comes on, there's a faint white flash on the screen, then black. The blue light stays on the whole time, but I see no faint picture with a flashlight.
If the video source (hdmi) is removed, the light does go orange. Tested with a VGA source, and it just goes orange.

I am not able to get the menu to come up either.
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Old 06-27-2014, 03:21 AM   #654
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Default Re: Hanns-G HG281D, LCD Monitor no power

Ok - you need to do the tests mentioned in this thread (by the way recommend you do not treat hdmi as plug and play - switch off first.)
First quick test might be to unplug the cable form the main/logic board that goes to the panel then switch on and see if the back light stays on.
Next plug it back in and test the voltages on the connector between the power and main.
Do you have any spare ccfl lamps , an old screen of a laptop etc.
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Old 06-27-2014, 06:12 AM   #655
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Default Re: Hanns-G HG281D, LCD Monitor no power

Quote:
Originally Posted by selldoor View Post
Ok - you need to do the tests mentioned in this thread (by the way recommend you do not treat hdmi as plug and play - switch off first.)
First quick test might be to unplug the cable form the main/logic board that goes to the panel then switch on and see if the back light stays on.
Next plug it back in and test the voltages on the connector between the power and main.
Do you have any spare ccfl lamps , an old screen of a laptop etc.
With the main board disconnected to the panel, and no source plugged in, the screen goes all white for a second, before going dark and the indicator turns yellow/orange. If I have the hdmi plugged in, it quickly flashes white, then goes dark.

Testing voltage from power supply to main board is 5v DC.

Was there a concise test list on a specific post? Thanks!

I do not have a spare ccfl lamp :/

Last edited by mack505; 06-27-2014 at 06:20 AM.. Reason: added
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Old 06-27-2014, 06:42 AM   #656
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Default Re: Hanns-G HG281D, LCD Monitor no power

Sorry to Hijack this thread once more but I got some really good help in this thread.


I have a Dell 24 inch monitor that has a what at first seems one vertical line on the right side about 3 or 4 inches in from the edge. But upon further inspection it seems to be a color line like 3 colors possibly. It is only the one 3 color line. the rest of the monitor works perfectly

Does anyone know what causes this? I mean, Which part needs fixing, Tconn, PSU or Mainboard? OR is it something else? Can I just change out all the caps and fix this or is this indicative of another issue altogether?

Sorry but no one will answer anywhere else for some reason. This thread helped me save my Hanns.
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Old 06-27-2014, 06:54 AM   #657
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Default Re: Hanns-G HG281D, LCD Monitor no power

Mac 505
Testing voltage from power supply to main board is 5v DC.

5v on all pins?


Was there a concise test list on a specific post? Thanks!
No Just have to read through and when you get to one do it.
Did you read this : http://www.badcaps.net/forum/showthread.php?t=10419 start at post 19 - lots of tests mainly without power
Also if you have an ordinary cfl bulb you could try this:
http://www.badcaps.net/forum/showthr...x+dx-40l261a12
If you can get to the inverter transformers.
Do you have another monitor you could try plugging the lamps into?
If not and no test bulb then perhaps make one of these
http://www.badcaps.net/forum/showthr...er+testing+cfl

Also try lighting up the monitor with only one lamp plugged in at a time. It wont ever stay lit but if one lamp doesnt light at all then it or its wiring is bad. If you find one like that try in another lamp socket if it will reach.
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Old 06-27-2014, 08:02 AM   #658
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Default Re: Hanns-G HG281D, LCD Monitor no power

Quote:
Originally Posted by selldoor View Post
Mac 505
Testing voltage from power supply to main board is 5v DC.

5v on all pins?


Was there a concise test list on a specific post? Thanks!
No Just have to read through and when you get to one do it.
Did you read this : http://www.badcaps.net/forum/showthread.php?t=10419 start at post 19 - lots of tests mainly without power
Also if you have an ordinary cfl bulb you could try this:
http://www.badcaps.net/forum/showthr...x+dx-40l261a12
If you can get to the inverter transformers.
Do you have another monitor you could try plugging the lamps into?
If not and no test bulb then perhaps make one of these
http://www.badcaps.net/forum/showthr...er+testing+cfl

Also try lighting up the monitor with only one lamp plugged in at a time. It wont ever stay lit but if one lamp doesnt light at all then it or its wiring is bad. If you find one like that try in another lamp socket if it will reach.
V- DC
Black -.02
Brown -0
Green - 0
Red - 4.97
Orange - 0
Yellow - 0

Brown - 4.95
black - .05
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Old 06-27-2014, 08:18 AM   #659
selldoor
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Default Re: Hanns-G HG281D, LCD Monitor no power

See post 555/556 and try that if you have a resistor 500 - 1 k ohm.
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Old 07-31-2014, 06:50 PM   #660
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Default Re: Hanns-G HG281D, LCD Monitor no power

Hello All! Just got my hands a used Hanns G HG281D. The screen will sometimes stayed powered on for ~1+ hours, or only a few minutes. The main issue is the screen "flickers" and has these horizontal squiggly lines. When the screen goes black, the power light would stay blue. I replaced the c83 and c80 caps, but now the screen will not power on at all, no lights - nothing! I've even tried re-soldering the caps. Did I fry something?
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