Hanns-G HG281D 28" TFT - Multiple Problems

[stevekasian]

Hi, all. It's been over a decade or so since I posted here. In that time, I'm sure certain folks have passed away or otherwise disappeared.
I remember this being a business, where the person running the board did repair work for hire, whilst helping DIYers at the same time.
Is there still a patriarch here who would be willing to replace my caps for hire if I send my board in?

I acquired another Hanns-G HG281D which eventually fell victim to some bad cap issues. I would love to replace the caps myself, but I've since developed Parkinsons tremors, and can no longer do board work as a result.

Thanks!

[jd101506]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

I should also note: I can "adjust" the backlight via the menu. As in, the brightness bar itself will go up and down at command but it doesn't affect the backlight itself.

I can post pictures if need be, but I haven't touched any of the backlight stuff itself. I've also left the monitor on for 20-30 minutes with no change.

[jd101506]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

Hey all, new to the forums and it seems like we have some pretty great knowledgeable users. I have a HG281D Rev 2 (MFG date: 2009) that I've replaced the caps on.

Prior to the replacement the monitor would turn on briefly and then I'd lose picture. It would stay "on" but there was no picture. After waiting for roughly 25 minutes with it on, the picture would return. I was able to play games, surf the web, and use as normal. Wanting this to be permanent... I replaced the PSU caps with the kit from LCDAlternatives. This didn't fix the issue. So I went ahead (Being stubborn) and replaced the caps on the logic board. The monitor came on! It works great now aside from one glaring issue... It is stuck at minimum brightness.

The monitor will come on, and it allows me to adjust brightness but nothing actually happens. Very odd. I know the backlight works as it comes on 100% for 1/4 second before going dim. I can adjust the contrast, picture hue, and everything else BUT backlight. Is there a specific cap that controls this? The backlight was working prior to replacing the caps on the logic board.

Any pointers would be awesome. Thanks all!

[budm]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

Great and thanks for the follow-up.

[gordesky1]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

Have great news!!!.

Monitor works like brand new now! Was much easier than on the computer board, Every problem is now fixed the interference lines and the white dots, And also the monitor brightness controls, Now i can finally turn the brightness down now lol

At first i thought it was something else causing that problem like the button board. But nope was those 2 caps that budm said!

Thank you very much for the help budm!!! If it wasn't for you i wouldn't even know if the caps was even bad or those 2 was the problem ones lol


I posted some pics and of my soldering, Not the best but i don't think its bad well i hope not lol.

[budm]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

It looks OK from the pictures. The MB is more than 10 layers board, so it will be a little easier for the main board of the monitor which may be 4 layers at most. Using extra flux also a big helps.

[gordesky1]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

Did i do any damage to the board in the pics? i didn't bother cleaning any flux off sense the board pretty much wont get reused. Just want to make sure before i do the real deal hehe.


Yea im going to try and get a better soldering iron, Tho for some reason this 30watt one is pretty good if i leave it sit for 20mins, As soon as i touch the solder it melts. when i did what you told me pretty much the caps pretty much came right out as soon as i touch the solder.

[budm]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

BTW, to clear the solder holes, you can use a small sewing needle attach to a wood stick, push the needle one one side of the board while heating the opposite side with the soldering iron, to make the job easier without damaging the board is to use 50~60W iron with 3mm wide tip.

[gordesky1]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

just tried that now while putting very little pulling with needle noses and got 2 of the caps off that i need Thanks


Also i posted a couple cause i wanted to make sure if i did it right with out damaging the board before i start on the monitor board, Don't want to damage that.


Pretty much this is the first i did this on a board lol

[budm]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

Adding solder to legs of the parts will make it easier to remove while moving the soldering tip back and forth between the two legs.

[gordesky1]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

cool As soon as i can get a solder sucker pump cause with out one its a pain in the ass lol

Was practicing on the dead board getting the bad swollen caps off i got them off but was a bit of a pain, Than trying to get the smaller caps that i need off it is pretty much impossible for me with out a pump.

The wick works but ony to a point.

Having a 30watt iron doesn't help either:/ It melts the solder tho.


Will give a update on it when i do it Hopefully in a day or 2.

thanks.

[budm]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

Same or higher Voltage will be fine, the one that is connected to the output of the regulator can be 10V.

[gordesky1]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

I have a old foxcon motherboard that's bad, And the caps on it are rubycons which i did a search and saw they are decent?

Im wondering if i can use them off that to replace those 2 with?

Tho it needs to be the same voltage right 16v? So far i do see 1 16v on the board, Mostly all the others are 10v...



Edit there's couple 16vs rubycon a0640 Will those work?

[budm]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

The two caps on the main board should be replaced, see my picture of the board in post 151 above. Bad cap can look normal.

[gordesky1]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

I posted about my 281 before in another thread, But i had really bad problems, Like the display will go off and come back on and also had these 3 other problems which i still do.

3 days ago i needed a monitor cause i had to put the tv i was using as a monitor in my bedroom again, So i decided to try this beast again, So far it never goes off now and looks perfect.

But i still have the vertical lines of shimmering pixels that would rapidly "sparkle" as the thread starter said in his post. Than i have another problem that i cant adjust the brightness from 100 unless i keep messing with it and i can get it to go down. Currently at 70.

And sometimes will have wavy lines like interference. When i first turn it on from cold you can see it pretty good, But when its on for hours its hard to see but its there.

I had this monitor apart months ago and i couldn't find a problem that i can see, But it still can be a bad cap even tho its not bulged.


i wonder what cap or part that will cause these 2 issues?

Pretty much the screen is flawless other than those 3 issues.

Would like to get it perfect sense these screens are wonderful. I have a 27inch screpture 1080p which i replace this monitor with back than because of these issues and mainly when it was going on and off. And lets say that monitor cant even compare to this monitor!

[Lumberjack777]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

Try replacing the two caps on the logic board, use low esr caps.
http://s807.photobucket.com/user/bud...?sort=3&page=1

budm was talking about the main/logic board. That's what causes the flicker. Not the power board.

I took apart the monitor yesterday just to see which caps it has.

Ok. That's the power board. Since you have lights, picture, and on screen video. That part is working. The flickering is caused by the main/logic board. I'll attach a picture from budm where he shows which 2 caps to replace. This is through hole soldering. A bit more difficult. But feel free to ask questions on it. Just replace those 2 caps and you should be good to go

[taktikz]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

I took apart the monitor yesterday just to see which caps it has. Since I couldn't really tell, I took pics in case the BadCaps community might recognize them. Here they are:

[budm]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

100uF 16VDC is what you have , right?
FR: http://www.digikey.com/product-detai...391-ND/2433525
FC: http://www.digikey.com/product-detai...1198-ND/356102

[selldoor]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

As budm says - Panasonic FM/FC/FR series will be fine. you need to read the V and UF
off the existing caps and look them up - you need to get ones that will physically fit
so same height and diameter if possible

[taktikz]

Re: Hanns-G HG281D 28" TFT - Multiple Problems

http://www.digikey.com/product-search/en/capacitors

I've never done this before. Any specific ones I should look at?