Hanns-G HG281D, LCD Monitor no power

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

I had a HannsG HG281D up on eBay defective and someone called me and told me that I could fix it easy based on my description of the problem on eBay.
2007 model
I took the monitor apart and I cant find any caps that are not flat.

I am wondering if it could be something else causing the problem?

1. The monitor takes a few seconds before the screen comes on sometimes and other times it takes 30 seconds or longer or I have to keep turning the button on and off.
Also sometimes I hit the button and it doesn't come on and I have to hit it again.

2. when it works( I get it to come on every time) it works flawlessly for 45 minutes. It is always playable with a game but light blues start to get this noise in it. Also other colors do too but the light blue seems to be the easiest to see the noise. What I mean by noise is like light snow or light flickering pixels though I don't think its pixels doing it but I Could be wrong.

I cant seem to find bad caps or any reason why its doing this.
Unless a cap can be bad without swelling up high and just every so slightly imperfect would do all of this.


Do I need to junk this Monitor? Could the panel be bad?


It seems I have all the issues from the last few posts.

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

I took the monitor apart and I cant find any caps that are not flat.

Just because a cap looks flat and "good" doesn't mean that it really is. The only way to tell is with an ESR meter and the cap out of circuit (and there are a few cases where even the ESR meter can get fooled) - but ESR meters are fairly pricy to justify buying for just a few repairs.

The logic board on these monitors is know to have several small caps fail without any visual signs - I think it was C80 and a few others. And if I remember correctly, some people did have very similar problems to yours. So I would suggest you go ahead, read the thread (at least the first few pages), and change the affected caps on the logic board, as well as a few on the PSU that are also common failure parts for other.

Sorry for not being able to be more specific. It's been a while since I posted any help on this particular thread, and it has escaped my head which caps are exatly the problem. I'd like to search the info and find it for you and point it out again, but it's 1:20 AM here, so maybe not today.

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

Here are the boards to my Monitor.

I took it apart last night on the bench and my brothers three kids are here so I am a bit concerned.
I circled a socket in Purple on the PSU. Well it isn't a circle. But its a purple attempt at a circle.
Can anyone tell me if there is a wire that plugs into that socket?
I do not have a wire anywhere on the monitor this morning to connect to that socket and I cannot remember if I disconnected something from it last night.
If I had disconnected a wire from it then it would be sitting with the monitor as everything else is unless the kids decided to play games. I am wondering what that socket goes to and if I am going to need to now buy a replacement wire for this.

Also, Can anyone visibly see any bad caps on these boards or any other potential problems?

I believe the guy who sold me this monitor already attempted a repair on it. I just think he tried to cheap his way through it.

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

Can anyone tell me if there is a wire that plugs into that socket?

Not sure. But judging by the pictures in the post below, looks like no (so you should be okay):
https://www.badcaps.net/forum/showpo...&postcount=145

I believe the guy who sold me this monitor already attempted a repair on it. I just think he tried to cheap his way through it.

Indeed he/she did. Those green and purple caps on the power supply board (on the first picture you posted) are definitely NOT original. Moreover, they look like cheap general purpose caps, and with all of the heat in an LCD monitor, they won't last long at all. And worst of all, he didn't even replace the caps that create the start-up problems on this power supply.

Reading previous pages from the thread, it seems that the offending caps on the power supply that need replacement are C603, C606, and C707 (all small caps between the two heatsinks in the center of the board).
However, I also suggest replacing C605, C108, C111, and C114 for good measure.

You will also need to provide us with everything that is written on the bigger caps on the right side of your board because I see some vent stamps that aren't typical, and if previous owner replaced caps with improper ones, they will need to be changed too.

Here's a cap diagram, courtesy of mooses
https://www.badcaps.net/forum/attach...2&d=1341463821
If you don't want to waste time figuring out what the previous owner replaced, you might as well replace all the caps #11 throuhg #22 on that diagram above.

Preferred replacement capacitor choice is Panasonic FC, FR, and FM series. Nichicon PW, PM, PS, and HE series, Chemicon KY, KZE, LZY, or LXZ series, or Rubycon ZL, ZLH, and ZLJ series are great too.

Also, Can anyone visibly see any bad caps on these boards or any other potential problems?

Yes.
The slow startup time and/or artifacts on the image for these monitors is caused by bad caps on the logic board (the 4th picture you attached). If you look at the top left corner in that picture, you'll see two black rectangular components (where it says V33S and V18S) - those are linear voltage regulators, and in this monitor they run HOT. This cooks the small surrounding caps over time, so you'll have to replace them. C80 is one of those caps that I remember very well now, is affected.

So replace at least C80, C83, C74, and C77. In my opinion, replace all in that area for a good measure. It's only 3 more caps anyways - C8, C13, and C14.
The two bigger ones (C80 and C83) are 16V, 100uF. Feel free to use caps 16V or 25V -rated caps if they fit. As for the capacitance (uF rating), if you really can't find 100 uF, the next very common size up (220 uF) should be okay. The smaller caps are 16V, 10 uF. Their value isn't very critical, so get replacements that are rated for at least 16V (16V, 25V, or 50V are all fine), and 10uF, 22uF, or 47 uF should all work fine.

Sounds like a lot of work, I know, but it isn't THAT much actually.

Other posts I found useful so far (posting for myself for future reference):
https://www.badcaps.net/forum/showpo...6&postcount=64
https://www.badcaps.net/forum/showpo...3&postcount=80
https://www.badcaps.net/forum/showpo...6&postcount=81
https://www.badcaps.net/forum/showpo...&postcount=104
https://www.badcaps.net/forum/showpo...&postcount=336
https://www.badcaps.net/forum/showpo...&postcount=396

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

Not sure. But judging by the pictures in the post below, looks like no (so you should be okay):
https://www.badcaps.net/forum/showpo...&postcount=145


Indeed he/she did. Those green and purple caps on the power supply board (on the first picture you posted) are definitely NOT original. Moreover, they look like cheap general purpose caps, and with all of the heat in an LCD monitor, they won't last long at all. And worst of all, he didn't even replace the caps that create the start-up problems on this power supply.

Reading previous pages from the thread, it seems that the offending caps on the power supply that need replacement are C603, C606, and C707 (all small caps between the two heatsinks in the center of the board).
However, I also suggest replacing C605, C108, C111, and C114 for good measure.

You will also need to provide us with everything that is written on the bigger caps on the right side of your board because I see some vent stamps that aren't typical, and if previous owner replaced caps with improper ones, they will need to be changed too.

Here's a cap diagram, courtesy of mooses
https://www.badcaps.net/forum/attach...2&d=1341463821
If you don't want to waste time figuring out what the previous owner replaced, you might as well replace all the caps #11 throuhg #22 on that diagram above.

Preferred replacement capacitor choice is Panasonic FC, FR, and FM series. Nichicon PW, PM, PS, and HE series, Chemicon KY, KZE, LZY, or LXZ series, or Rubycon ZL, ZLH, and ZLJ series are great too.


Yes.
The slow startup time and/or artifacts on the image for these monitors is caused by bad caps on the logic board (the 4th picture you attached). If you look at the top left corner in that picture, you'll see two black rectangular components (where it says V33S and V18S) - those are linear voltage regulators, and in this monitor they run HOT. This cooks the small surrounding caps over time, so you'll have to replace them. C80 is one of those caps that I remember very well now, is affected.

So replace at least C80, C83, C74, and C77. In my opinion, replace all in that area for a good measure. It's only 3 more caps anyways - C8, C13, and C14.
The two bigger ones (C80 and C83) are 16V, 100uF. Feel free to use caps 16V or 25V -rated caps if they fit. As for the capacitance (uF rating), if you really can't find 100 uF, the next very common size up (220 uF) should be okay. The smaller caps are 16V, 10 uF. Their value isn't very critical, so get replacements that are rated for at least 16V (16V, 25V, or 50V are all fine), and 10uF, 22uF, or 47 uF should all work fine.

Sounds like a lot of work, I know, but it isn't THAT much actually.

Other posts I found useful so far (posting for myself for future reference):
https://www.badcaps.net/forum/showpo...6&postcount=64
https://www.badcaps.net/forum/showpo...3&postcount=80
https://www.badcaps.net/forum/showpo...6&postcount=81
https://www.badcaps.net/forum/showpo...&postcount=104
https://www.badcaps.net/forum/showpo...&postcount=336
https://www.badcaps.net/forum/showpo...&postcount=396

Maybe I am missing something, But you are referencing the caps by numbers and letters. How do I know which is which? Is it stamped on the board somewhere? As of yet I haven't been able to find any numbers that have been referenced.

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

I finally found the reference numbers.

The only issue I have now is knowing where can I purchase all these caps and parts?

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

Sometimes I miss things from reading quickly.

I see completely that you did show me where the caps were. I just didn't look thoroughly.

I just did the very same thing I detest that others do on forums!!

[Lumberjack777]

Re: Hanns-G HG281D, LCD Monitor no power

On a megathread such as this, it's tough to read through everything. Confusing even.
If you go back a few pages, then read to the end; you'll see I post a pic of the caps needing replacement on the power board, and budm shows the 2 caps that need replacing on the main board.

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

The only issue I have now is knowing where can I purchase all these caps and parts?

Mouser.com
Digikey.com
https://www.badcaps.net/store/ (this place , although you may not find all of the small caps you need for this monitor)

On a megathread such as this, it's tough to read through everything. Confusing even.

Indeed.
Even I had to start back at page 1 and go forward till I found all of the info I needed. But it's all good. I mean, what else is there to do on a Saturday night for a college student that doesn't like to party .

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

Are these PCB's 6 layer like a Motherboard?

What I mean is, How important is it that the solder must make a solid connection all the way through the hole?
I say this because I wonder if the caps the person who fixed this board before me used were just not soldered correctly.

It appears to me that in the second picture in on my post #603, the soldered pin for the large aluminum cover appears to have been removed and
re-soldered like an amateur. It appears to show some copper like his iron melted the PCB's top green layer a bit.

It doesn't appear to have gone through the copper layer underneath but it certainly melted through the green top coating. That I can clearly see looking through it with a jeweler's loop but you cant see it in the picture because the picture blurs a bit in that spot.

Do you think this could have caused the issues I am having?

If you need a really super clear picture of that specific spot I will attempt to get one of it. MY camera has a 26x zoom and it can get some serious detail if I make the effort.

I am just curious if with this issue there are other layers in these PCB boards and knowing the guy who fixed this is a jacka$$ is there a chance I am wasting my time trying to fix his work?

Because the truth is, He fixed this monitor for the purpose of selling to me and I can surmise that he fixed a bigger issue of the monitor not coming on and didn't know about this problem since maybe he checked to see if the monitor worked and never used it for more than 45 minutes and assumed he had fixed enough or maybe he tried to fix this problem too and in the end couldn't.

I know this is a mess of a bunch of considerations but of course that is what you get when you are trying to fix someone else's mess. Which I have made a living doing in the construction industry.
It is frustrating to have incomplete data on his originally purposed repair job in a subject I am not familiar with. If I knew exactly what he tried or did fix I would feel more secure that changing out these caps is going to fix the issue.

But if you guys who know your stuff (so far momaka and Lumberjack777) tell me that his shoddy spot work on that one lead is ok I will certainly feel secure in doing this fix myself.

[Lumberjack777]

Re: Hanns-G HG281D, LCD Monitor no power

Ok. I'm going to make this simple for you. I have repaired many of these.

I can't quite tell the area you are talking about but it's ok if some of the green coating is missing as long as there is no break in the copper trace. If there was a break it wouldn't turn on at all.

To put it simply. He replaced the WRONG CAPS on this power board. The ones you need to replace are the little ones in the middle. They dry up. Every time. I attached a picture with the caps you need to replace. They are circled in red. The power board is not a "through hole" board like motherboards. The capacitors are connected with the solder to the copper trace on the bottom of the board. When you are desoldering make sure to heat the solder on the cap lead and pull straight out. Wiggling back and forth CAN break the copper trace. Just pull straight out.

The 2nd picture (the main board) IS a "through hole" soldering board. You need to replace the 2 caps budm mentions on that picture.

You can find good caps at Digikey. Try for Panasonic FM or FR series.

That's it. Just replace those 5 caps, and you are good to go.

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

If there was a break it wouldn't turn on at all.

Indeed

To put it simply. He replaced the WRONG CAPS on this power board.

Yes.
But I still encourage abeeftec to replace even those wrongly-replaced caps because it looks like the original owner got some real "cheap-and-dirty" caps either from eBay or a local store. And given how hot these PSUs run, they are bound to fail sooner rather than later.

So not just the little ones but all of the caps on the output side of the power supply. It would run you maybe $10 extra, but it's well worth it. That is, replace #11 through #22 on this diagram:
https://www.badcaps.net/forum/attach...2&d=1341463821
The originals were Chemicon KY, which are very good quality capacitors. But you can use any of the other capacitor choices I suggested. Panasonic FM and FR are excellent!

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

Thank you both! I appreciate it greatly.

I will let you know how it goes but it could be a while as I just got pounded with work.

I will post back when completed.

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

Indeed


Yes.
But I still encourage abeeftec to replace even those wrongly-replaced caps because it looks like the original owner got some real "cheap-and-dirty" caps either from eBay or a local store. And given how hot these PSUs run, they are bound to fail sooner rather than later.

So not just the little ones but all of the caps on the output side of the power supply. It would run you maybe $10 extra, but it's well worth it. That is, replace #11 through #22 on this diagram:
https://www.badcaps.net/forum/attach...2&d=1341463821
The originals were Chemicon KY, which are very good quality capacitors. But you can use any of the other capacitor choices I suggested. Panasonic FM and FR are excellent!

I just wanted to let you know that one of those caps, the large purple one is 1000uF 16v and all of the green ones are 470uF 16v.
Greens say Jaro or Japo on them. And the purple one says, ceS

Are these way bigger than what was initially on this board?

Also,

I had a question about Soldering irons. I have three of them. a 30w 40w and 45w.

Two are from Radio Shack and one is the exact same iron but not labeled Radio Shack.

I attached a picture of them.

I got the soldering iron a few years ago with the solder sucker tool. And recently I acquired the other iron while purchasing a laser printer that came with 7 bottles of toner refill and two cartridges.

The one with the soldering tip is the 30w
The one with the solder sucker tip is 45w
And the one with the hole maker is 40w.

Are the Solder sucker and soldering iron set up with the right wattage already?
That is how they came new.

I just want to make sure I am not making mistakes before I start.

I am going to practice on a bad motherboard and a couple bad circuit boards before I do this on my PSU and Mainboard.

Sorry for all the questions but I am a total solder noob.
I tried once to put a power jack back on a laptop and it worked intermittently with the jack completely just sitting there but once I soldered it that made it not work. But I think I put too much heat on it and didn't let the irons sit long enough before trying it. The laptop never started again.

So, because of that I will become a solder pro before I do this.

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

Ok,
I am now including a picture of something I found on the PSU that is very suspect but I need an opinion. Q601


This voltage regulator(Q601) appears burnt. Especially when I compare it to the guys on the first page!
I cant even read my Q601 all the way and had to look at the board on the first page just to get the number and letter completely.
Could this cause all the issues I described in my first post?

I know I am a pain aren't I? My apologies. Just worried about spending money to fix all those caps and still having the same issues(Plural)I was having.

I took three pictures at different distances in case. I don't know if this is normal for a voltage regulator or not.

There is clearly a darker spot on the other side of the board where it looks like the board took some heat there. Is this normal?

[Lumberjack777]

Re: Hanns-G HG281D, LCD Monitor no power

I just wanted to let you know that one of those caps, the large purple one is 1000uF 16v and all of the green ones are 470uF 16v.
Greens say Jaro or Japo on them. And the purple one says, ceS ..........

So, because of that I will become a solder pro before I do this.

I'll answer these 2 first. Those are the wrong caps. You need to change them with good ones of the right size and type like momaka mentioned.

If you want to become good at soldering. Yes, it's good to practice. Totally smart. Also make sure to watch this video. Credits to retiredcaps for this link.
http://www.youtube.com/watch?v=I_NU2ruzyc4

It's hard to tell on the Q601. What's the exact part number; so we can tell you how to test it.

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

I'll answer these 2 first. Those are the wrong caps. You need to change them with good ones of the right size and type like momaka mentioned.

If you want to become good at soldering. Yes, it's good to practice. Totally smart. Also make sure to watch this video. Credits to retiredcaps for this link.
http://www.youtube.com/watch?v=I_NU2ruzyc4

It's hard to tell on the Q601. What's the exact part number; so we can tell you how to test it.

How would I find the part number? That is a voltage regulator correct?

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

I had a question about Soldering irons. I have three of them. a 30w 40w and 45w.
...
The one with the soldering tip is the 30w
The one with the solder sucker tip is 45w
And the one with the hole maker is 40w.

Are the Solder sucker and soldering iron set up with the right wattage already?

Technically, you should be able to do the recap with any of these. However, since you say you are a "first-timer" more or less, I would say take the tip from the 30W iron and put it on either the 40W or 45W iron. The extra 10 to 15W will make the solder melt a little easier.

The most important thing, though, is to let the iron heat up for a good 5 to 8 minutes before you try to use it. When heating up a joint, it will usually help if you add fresh solder to it. Better yet, buy some no-clean electronics flux (both gel and liquid will work fine... just avoid plumber's flux, that's all) and put it on all joints you intend to solder. It will greatly help with the heat transfer from the iron to the joint. Don't heat solder joints for more than 10 seconds. Usually 3 to 5 is enough. If solder is not melting, try adding more flux (or solder, if you don't have flux).

Generally, this is the "walking/rocking" method I use for removing caps:
https://www.badcaps.net/forum/showpo...7&postcount=23

For the power board, however, you may use the 45W iron with the solder sucker bulb. Instead of the above method, just put the solder sucker iron tip over each cap's leg, let it heat and melt the solder fully (for maybe 3 to 5 seconds), then release the bulb and the solder should get sucked out.

For the logic board, I suggest using the "walking/rocking" method as it has multiple layers and the 45W solder sucker iron may not work too well with it. In fact, what I often do with multi-layer boards like that is I never try to clear the holes completely after removing the caps. Instead, I just use a cork board tack/pin, heat each joint, and then make indentations in the solder holes on the othe side as I am heating the solder with the iron. Then I pre-cut the leads on the new caps and place them over the indentations (pro tip #351: always check that polarity on cap matches the board... nothing more embarasing than installing it in reverse, then noticing your mistake... I've done it quite a few ). Then I use the "walking/rocking" method in reverse.

Could this cause all the issues I described in my first post?

Not the "funky pixels" issue.
It appears this is on the power supply board, so if something was wrong with this transistor, your monitor very likely would not have powered on at all.

The issue with the image is caused by the caps near the regulators on the logic board (C80 and surrounding caps).

That is a voltage regulator correct?

Transistor (either MOSFET or BJT). The "Q" prefix from the "Q601" label on the board gives you this info. Voltage regulator usually has "IC" or "U" prefix.
But like I said, you need not worry about it if the monitor powers on right now. I think the original owner has tried to resolder it and that's why there's a burn mark. The solder on its terminals doesn't look like from the factory to me.

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

Indeed


Yes.
But I still encourage abeeftec to replace even those wrongly-replaced caps because it looks like the original owner got some real "cheap-and-dirty" caps either from eBay or a local store. And given how hot these PSUs run, they are bound to fail sooner rather than later.

So not just the little ones but all of the caps on the output side of the power supply. It would run you maybe $10 extra, but it's well worth it. That is, replace #11 through #22 on this diagram:
https://www.badcaps.net/forum/attach...2&d=1341463821
The originals were Chemicon KY, which are very good quality capacitors. But you can use any of the other capacitor choices I suggested. Panasonic FM and FR are excellent!

I feel like I haven't had more questions for something in all my life!

But this one at least isn't a question about how to!

On the link attacked in the quote above there is a cap 5 6 and 7

Cap 6 is identified below as 100v uF.

There is no uF rating! Any Idea what rating that cap is?

[abeeftec]

Re: Hanns-G HG281D, LCD Monitor no power

I feel like I haven't had more questions for something in all my life!

But this one at least isn't a question about how to!

On the link attacked in the quote above there is a cap 5 6 and 7

Cap 6 is identified below as 100v uF.

There is no uF rating! Any Idea what rating that cap is?

#6 is 100v 1uF

I took it out of the board to figure out it. It was the only one I couldn't see on the board because it was sandwiched between two other caps and it is the only one without a uF rating on the chart.