Hanns G HG281D 2 second black screen and parts help

[nuhhht]

Ya I have starting searching for PlainBill's posts also and can't thank him enough. I will have to check out the electronic's for dummies. Thank you for sharing your info with me.

[retiredcaps]

I found this youtube channel good for beginners interested in TV repair. He has 10 tutorials.

http://www.youtube.com/user/GrantsPassTVRepairs

He goes through a lot like how to test such and such. I have watched each more than once and it is starting to sink in now.

Originally Posted by nuhhht

Ya I have starting searching for PlainBill's posts also and can't thank him enough. I will have to check out the electronic's for dummies. Thank you for sharing your info with me.

[nuhhht]

Awesome man, thank you for the link!

[nuhhht]

I just replaced all but 2 small caps (which I will order and replace) and the same problems still exist as in the original post. Upon boot up of the computer the wavy text and flickering gets better over time (75% of the time)

I am also now hearing a hissing sound coming from the rear of the monitor? Any ideas? Also, when I minimize a full screen window the sound makes a different noise from the rear of the monitor.

[PlainBill]

Originally Posted by nuhhht

I just replaced all but 2 small caps (which I will order and replace) and the same problems still exist as in the original post. Upon boot up of the computer the wavy text and flickering gets better over time (75% of the time)

I am also now hearing a hissing sound coming from the rear of the monitor? Any ideas? Also, when I minimize a full screen window the sound makes a different noise from the rear of the monitor.

The hissing sound is probably either one of the CCFLs or it's wiring harness, or a problem with an inverter transformer.

The other problem may be a bad cap on the logic card. It's ESR is dropping as it heats up. Possibly carefully check each cap on the logic card to see if one seems warmer after a few minutes. (It's a long shot).

PlainBill

[nuhhht]

If I remeber correctly the inverter and the power supply were
the only compents with caps on them. I will take it apart and double check.

Why would the bulbs all the sudden start going out? Colors
and contrast seem fine.

[PlainBill]

Originally Posted by nuhhht

If I remeber correctly the inverter and the power supply were
the only compents with caps on them. I will take it apart and double check.

Why would the bulbs all the sudden start going out? Colors
and contrast seem fine.

Lead free solder, fine gauge wire, the metal used to make the pins on ccfls, etc are not a good combination. One common problem is a loose wire due to a bad solder joint.

PlainBill

[nuhhht]

I used 60/40 lead/tin. I will double check all the connections

[nuhhht]

Here are some quality photos of the power supply board. I did find some cold solders that I will have to redo.

Can you guys spot anything unusual or give me a direction to check next.

The green boxes on the caps are the ones I've replaced and the red's are the ones I haven't (yet)

If you guys want more pictures let me know.

[dipstick]

nuhhht

Just wondering if you got this figured out yet?

I have the same monitor but mine just turns black after about 10 sec, and the power light stays on. Doesn't matter if I hook it up VGA or HDMI, to a pc or a blu-ray, all the same. I tried the flashlight trick and its pitch black until I power off the monitor then I can see the light????? This was not a cheap monitor to just toss in the trash and replace. I have fixed other monitors before but this one has me stumped. Please lmk your progress. Thanks

[PlainBill]

Originally Posted by dipstick

nuhhht

Just wondering if you got this figured out yet?

I have the same monitor but mine just turns black after about 10 sec, and the power light stays on. Doesn't matter if I hook it up VGA or HDMI, to a pc or a blu-ray, all the same. I tried the flashlight trick and its pitch black until I power off the monitor then I can see the light????? This was not a cheap monitor to just toss in the trash and replace. I have fixed other monitors before but this one has me stumped. Please lmk your progress. Thanks

The question in every case like this is 'Is it a backlight problem or a logic card problem?". Every monitor I have seen has some leakage from the backlights, visible when the back of the monitor is off, or maybe even in a dark room. If the CCFLs are off, troubleshoot the inverter system. If they are on, it would be a problem with the video processing system.

PlainBill

[dipstick]

Originally Posted by PlainBill

The question in every case like this is 'Is it a backlight problem or a logic card problem?". Every monitor I have seen has some leakage from the backlights, visible when the back of the monitor is off, or maybe even in a dark room. If the CCFLs are off, troubleshoot the inverter system. If they are on, it would be a problem with the video processing system.

PlainBill

Thanks Bill, I will give that a shot. I did end up testing the caps on the logic card with a ohm meter and the small ones dont seem to be working correctly. Im going to replace them today and get it put back together to check if the ccfls are on or not when the screen goes black.

[josesantiago1983]

answer is the logic card had same problem so i bought a new hannsg hg281d. and tested by doing switch so power supply is good but when i put the new logic card then the flickering is gone and wont turn off wont go to sleep mode like it did before .now it work great so i order a logic so the problem is not power supply

dude to many people will get you confuse
so the power supply look good by looking at the caps dont mess with its
you need a new logic card winch cant be fix
only hannsg got it in stock

[QUOTE=nuhhht]Hey guys,

I have a Hanns G HG281D 28" 1920x1200 5ms monitor that has recently started to show symptoms of a bad inverter ie: the screen would show grey lines of brightness (flickering kind of) the icons on the desktop would look as if they were being shaken. Also, randomly the screen would turn off but the power led light would stay on.

[avetcj]

Hi,
Where can I order a new logic card? Thanks



[QUOTE=josesantiago1983;115014]answer is the logic card had same problem so i bought a new hannsg hg281d. and tested by doing switch so power supply is good but when i put the new logic card then the flickering is gone and wont turn off wont go to sleep mode like it did before .now it work great so i order a logic so the problem is not power supply

dude to many people will get you confuse
so the power supply look good by looking at the caps dont mess with its
you need a new logic card winch cant be fix
only hannsg got it in stock

Originally Posted by nuhhht

Hey guys,

I have a Hanns G HG281D 28" 1920x1200 5ms monitor that has recently started to show symptoms of a bad inverter ie: the screen would show grey lines of brightness (flickering kind of) the icons on the desktop would look as if they were being shaken. Also, randomly the screen would turn off but the power led light would stay on.

[bosnia58]

did anybody try to get power board anywhere online that would be easy fix just put new board and done instead changing capacitors or some other parts.

[PlainBill]

Originally Posted by bosnia58

did anybody try to get power board anywhere online that would be easy fix just put new board and done instead changing capacitors or some other parts.

By the same logic, why mess around changing oil, buying new tires, or adding gas to a car - just buy a new car when the gas tank gets empty.

PlainBill

[PCBONEZ]

Replacement cards usually get you fresh BAD caps.
.

[gretti]

So I had the same problem with the backlight turning off and squiggly lines. At first I re-capped the power board which did not fix the problem. Then I found two 100uf 16v by the two power transistors that were bad. Problem fixed after I replaced them.

[allanlloyd]

As a NEW member ,the posts are great with the exception of all the values of the caps are given but not the circuit location such as C1,C2 etc. They are all marked for the circuit reference and if quoted will make it easier to get to the correct caps . The 22/450v cap is the start up

[bjrothman]

Originally Posted by gretti

So I had the same problem with the backlight turning off and squiggly lines. At first I re-capped the power board which did not fix the problem. Then I found two 100uf 16v by the two power transistors that were bad. Problem fixed after I replaced them.

Sorry to resurrect a old thread, but I was having this issue too and replacing all 3 of 100uf 16v caps on the logic board fixed the issue for me. I salvaged some caps from an old usb2 pci card, so with a little extra work, it cost me $0.00. woot!