Hanns-G HG281D, LCD Monitor no power

[sosueme]

Greetings from a newbie....I have the same problems (originally had to hit switch over and over to get screen to fire up...now I have nothing for either screen or light)....this may be a sin on this board (an if it is please accept my apologies!) but would one of you who has done the capacitor replacement and knows all the part numbers be willing to look at my boards, replace what you think needs replacing and bill me accordingly?

[retiredcaps]

Originally Posted by sosueme

but would one of you who has done the capacitor replacement and knows all the part numbers be willing to look at my boards, replace what you think needs replacing and bill me accordingly?

If you are not willing to do any of the work, then you can buy "kits" from ebay sellers. I'm not a fan of them because they often cheap out and inexplicably leave out some caps for the sake of cutting their costs by $1 and/or boosting their profits. In addition, manufacturers often have different revisions of the same board so caps are added, removed, and/or modified.

If you have problems with the kit, contact the seller for technical support and help. They get the $$$ so they should get all the support questions that go with the $$$.

If you are willing to do the work, then see my standard answers for examples on how to order the caps below. It is a "give a man a fish and you feed him for one day, teach a man how to fish and you feed him for life" approach.

The kit is the former and my examples are the latter.

http://www.badcaps.net/forum/showpos...84&postcount=3

Take your pick. There is no right/wrong approach.

[mooses]

I'm reading it as he doesn't have the know how or equipment to do the fixing (soldering and stuff) which is why he's asking if someone else could repair it for him.

[retiredcaps]

Originally Posted by mooses

I'm reading it as he doesn't have the know how or equipment to do the fixing (soldering and stuff) which is why he's asking if someone else could repair it for him.

If I go by that interpretation, then that is definitely a NO NO here if you go strictly by the rules. It is best to ask Topcat (the owner) if such a "one of" is okay or not since he normally doesn't recap lcd power boards (usually only computer motherboards).

From the owner himself ...

http://www.badcaps.net/forum/announcement.php?f=24

Badcaps.net IS A BUSINESS!!! If you are a servicer, service center, or vendor of any kind in the computer/capacitor industry, you are NOT permitted to advertise, link, promote, or plug your business on this forum in ANY way! NO EXCEPTIONS!! If I see you doing that, your post will be edited or deleted, and you warned. If it happens again, you will be banned. There will be no vending of capacitors or recapping services permitted on this forum!! The only exceptions are the references to the companies quoted in the FAQ which the administration have added for the convenience of those around the world who have difficulty to source caps for their repair.

This also includes using this forum's private message system to solicit business. Members, if you receive a PM from anyone offering repair services or components, please alert me immediately! Myself or any of my moderators, will never private message a user soliciting business, for Badcaps.net, or any other servicer/vendor. If you PM me about repairing your device, I will reply and take care of you, however, I will not message you first.

[rrogers]

Hi, I came across this thread when I had a problem with my HG281D and thought I'd post my experience for future users.

I had the same problem as the OP. After switching the display off for the 1st time in about 3 years. No response from the switch and no blue or orange LED. Measured the 5VSB and found it to be fluctuating between 4.2V and 4.9V with the PSU not connected to anything. I dont have the kit to test the caps so replaced all 7 around the small tansformers that seems to derive the SB voltage. Now 5VSB rock solid and all working again.

I'm in the UK and got the parts from R.S for about £17 (although only came in packs of 5 each so have plenty of spares if it goes again)

Many thanks to all who contributed on this thread, it's a long read but worth it.

[rrogers]

With regard to my above post, it was only 6 caps changed out

[Vizor]

Anyone got a extra Main board they wanna sell?

[Technigogo]

where do I get the replacement capacitors? I suspect C603,606 and 707 as well.

[usbdevice]

Hello all

First I'd like to thank everyone who has contributed to this thread and shared their experiences repairing this particular monitor.
Second, sorry for the long post. This is a success story so you might not even want to read this.

I bought my Hanns.g 4 years ago and it started showing first signs of failure about one year ago. The monitor would go black for a second or two, and then the image would come back.
For a couple of months now, when booting my pc the image would be fine, but a few seconds after logging in the screen would go black a take anywhere up to a minute or two before the image came back. Afterwards it would mostly run fine (even for an entire day) without going to black. Sometimes I'd see image distortion but never for very long, a couple of minutes maximum.
It seemed to me the problem was dependent on the signal the monitor was fed. I'm using Ubuntu Linux and for those of you not familiar with Linux, besides the graphical user interface there are text-only interfaces called consoles. When I'd switch to one of the 6 consoles, I'd never have the problem. In fact, I often successfully used this trick to get the picture back quickly, by switching to one of the consoles after the screen goes black, waiting a few seconds and switch to the Desktop again I would get the image back.

So, the symptoms: black screen, power LED always on (blue) even when screen was black, symptoms probably linked to input signal. When the screen was black, I could not see an image when shining on the screen with a bright flashlight.

Having read through this entire thread I took some measurements.
With only the PSU connected to AC power, I got 4.99V on the 5VSB rail, looks good.
Next I hooked up the main/logic board and the switches to the PSU. With AC power connected, I still got 4.99V on the 5VSB, still good.
When I hit the power button, the blue LED comes on, after 1-2 seconds all voltages appear, 5.11V on the 5VDC, 12.2V on the 12VDC and 23.98V on the 24VDC rails respectively. Where I'm not sure is the PSON signal, I was reading 3.12V there. Is that what it is supposed to be, I was expecting that to be 5V too? Maybe someone can comment on this?
After another second or two, the monitor goes into standby (amber LED) and all the rail voltages go back to 0V except for 5VSB.
I also measured the voltage across the large input cap C3 which was 380VDC which seemed fine too.

I didn't take any more measurements at this point.

It seemed to me the PSU was fine, at least the rails are where they are supposed to be.

I remembered reading this post earlier in this thread.
This sounded pretty much like what I was experiencing. And since I also noticed signs of heat on my logic board in that spot, I decided to give this a try first. I replaced C80 and C83 (all the electrolytics on my logic board are CapXCon by the way) both are 100uF/16V.
Success! The symptoms have completely disappeared.

Anxious to see if I had resolved the problem, I forgot take any measurements before I hooked up to monitor again. I really wanted to check the PSON signal again to see if the voltage had changed, I guess I will still do that soon.
The only thing I made sure of was that I had not created a solder bridge when replacing the caps by checking for a short between the two terminals of each cap.

On the topic of removing these caps, they were a b*tch to remove. The negative terminals are likely connected to the ground plane of the pcb and I had to turn up the heat on my iron quite a bit. Having had a couple of bad experiences with cheap pcbs in the recent past I didn't feel too sure about this but I managed to pull it off without damaging the board or traces.

The next time I have to order parts I will order a complete set of low ESR replacements for all both boards as I think it's just a question of WHEN the next caps will fail as opposed to WHETHER they fail at all.

I am including some pictures. What I forgot was to write down the revision numbers of the boards. The pictures aren't too good as I only have DSLR and no lens with a macro function and I had to shoot from quite a distance to get them into focus - and then there's not much depth of field.
I did label all the electrolytics with designations and values on the top view images though. Maybe this will be helpful to someone.
The PSU is the Phihong PSM217 404-h-r. As I wrote above, I'll include the revision nr. as soon as I can.

Again, thanks to everyone for posting here. This has been very educating!

Cheers
Lenny

[retiredcaps]

Originally Posted by usbdevice

Having read through this entire thread I took some measurements.

The "regulars" thank you for reading through everything. Almost everything that can go wrong with this monitor has been discussed in this megathread or its variants at least once.

Where I'm not sure is the PSON signal, I was reading 3.12V there. Is that what it is supposed to be, I was expecting that to be 5V too? Maybe someone can comment on this?

PSON is generated by the main/logic board. It is usually > 3V.

[Jacky60]

Originally Posted by cody_hb85

In search of a solution to the screen flickering, no power issue I've been having with my hanns g hg281d I came across this site. So I have been reading this thread and after everything is all said and done, I have gone ahead and completely replaced EVERY cap on my power supply with caps from Digi-Key. The blue light comes on now and stays on, goes into standby when no input is plugged in, comes back from standby and recognizes the input device when plugged in. Disply works, back light come on, everything is fine...... until...... the screen starts to get fuzzy, especially around desktop icons and dialog boxes. I've also read in this thread that it could possibly be the caps on the logic board? Please advise me on where to start! I will post whatever pictures you may need as soon as I get home from work this evening. Thanks in advance!

I have done exactly the same thing replacing all the caps on my power board. The monitor boots fine in safe but when I try and run it normally the same flickering fuzzy screen returns (there is much reduced flicker in safe). Not sure what to do next.

[selldoor]

Hi hopefully you will have used good quality low esr caps for the power supply.

Read this http://www.badcaps.net/forum/showthread.php?t=23592

and http://www.badcaps.net/forum/showthread.php?t=24000

Try replacing the two caps first but also check the voltage regulators

[Jacky60]

Does anyone know which caps the logic board requires (HannsG 281D) as I'd rather buy em in the UK rather than order them from USA.

[budm]

Please see here, I used Panasonic FM series: 100uF 16VDC
http://s807.photobucket.com/albums/y...t=DSC00085.jpg

[selldoor]

if you were unable to tell from the posts I suggested you will need to post pictures of your mainboard so we can be sure.
Welcome to the forum-
front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
http://www.badcaps.net/forum/attachm...1&d=1290283049

http://www.badcaps.net/forum/attachm...7&d=1280167246

It will be useful if you can say what the supposed fault was and a bit about yourself - skills tools etc.

[Jacky60]

I chose to look at the capacitors closely to see what they were, I was just being lazy asking, for the record my HannsG 281D logic board has:
3 x 16V 470mf
12 x 25V 10mf
5 x 16v 100mf

Is it OK to use caps with slightly higher voltage rating, I make sure I disconnect monitor when I am not using it as I doint want to burn down my flat?

[jetadm123]

Originally Posted by Jacky60

I chose to look at the capacitors closely to see what they were, I was just being lazy asking, for the record my HannsG 281D logic board has:
3 x 16V 470mf
12 x 25V 10mf
5 x 16v 100mf

Is it OK to use caps with slightly higher voltage rating, I make sure I disconnect monitor when I am not using it as I doint want to burn down my flat?

Yes, you can go higher in voltage. Just be aware that going higher in voltage may result in a physically larger cap. This can cause a potential problem if you have many caps clustered together.

[herbal718]

I have this same board and would like to replace all the capacitors in this picture. Would someone be able to find the right ones for me on digikey? I don't want to make a mistake and order the wrong ones. I am guessing to go with the Panasonic ones, or are there better ones, any help will be greatly appreciated, thank you.

[herbal718]

I found a bunch of these capacitors, the only difference I can spot among them is that they have different Ripple Current (mA) and Impedence (Ohm). Should I go with Rubycon caps instead of these Panasonic ones?

http://www.digikey.com/product-detai...1250-ND/356152
http://www.digikey.com/product-detai...0316-ND/266325

[selldoor]

FC s should be good for these smaller caps Two are close together and the 100L is 1mm wider