Hanns-G HG281D 28" TFT - Multiple Problems

[NeilH]

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

Ok, thank you for that offer, it's really good of you. I'll have a look online first to see if I can find somewhere else in Cardiff, surely Maplin can't be the only company here. especially if they're dodgy.
I've just put the monitor back together till after the weekend and it's working again at the moment so I didn't manage to break anything.
I'll be sure to let you know how I get on but there doesn't seem to be any components near those caps so I think I should be OK with a small soldering iron so a trip to Maplin might be on the cards regardless.

Right, I'm off to bed.
Goodnight Tom and take care.

[Vizor]

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

i will never again buy a Hanns-g have this monitor to and it Main Board went out last night smoking came back on with a red screen.

[retiredcaps]

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

I think Retiredcaps said something about these Chemicons drying up because these monitors run hot, but I'm not sure.

Somewhere either in the megathread or its various forks (I lost track)

https://www.badcaps.net/forum/showthread.php?t=11329

I came to the conclusion after helping others with this monitor (also manufactured under other brands) from day 1 that this monitor runs temperature hot and drys out caps on BOTH the power and main board.

This is the only monitor where I recommend a COMPLETE recap of every electrolytic capacitor on ALL boards. The caps might cost $20 to $25, but you are saving a 28 inch monitor.

This model alone is the 10th most viewed thread in the troubleshooting computer lcd forum so you know there are a lot of problems with it.

[deguello2003]

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

Gentlemen Thnkyou for all your help on repairing my monitor. I am having a major problem locating a replacement mother board for this computer. I have found several on line but all are sold if anyone has a spare or know where I can find one. I need it right away. If you do not know which board it is, it is the board next to power supple under the metal box with the ribbon cable to the monitor control board. Thanks Bill R Also a good source for caps with no minimum is Allied Electrical in Fort Worth Texas and they ship everywhere. Thanks again.

[Staubach]

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

Just read this and the other thread about the Hanns G issues, and I wanted to say thanks to everyone for the information.

I will give an update once I get the new caps!!

[Bartman]

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

It could be a number of problems causing this - as you say caps could be one and it could be the power supply the main board or both. It could also be the voltage regulators.
First thing perhaps would be to remove and reseat any connectors especially if their is a flat one to the panel which might need a clean.
Have you tried a different hdmi cable..
Have you tried it with a different pc.
As it says these run on the hot side so even if caps have no visible damage they could
still be dried out. As it is a 28 inch screen has to be worth investing in good new
caps. Start with the power supply and if no improvement test the voltage regulators
then re cap the main board. If you didnt want to do all the caps on the main board I would start with the ones near to the voltage regulator.

I checked with a different 'PC' (Pandaboard) and cable and this all seemed to go well allbeit with low resolution (640x480). I had to arrange a few things to be able to check my own computer (Macbook Pro) with a different cable. Mini Displayport to HDMI adapters are not very common and therefore pricy, so I did not want to buy a new one without knowing what the problem was. I finally arranged one and all looks fine. So it appeared to be the cable that was causing the problem! I reported to the seller and got a refund.
I checked on different forums and reviews and it appears that many MDP to HDMI adapters and cables are faulty. Not at first, but after a few weeks or months. The symptoms (screen blanking, garbled images, etc.) are identical to bad caps.
So I want to advise all of you who have a Mac to check your cable first before opening your screen or replace the capacitors!

And of course thanks to selldoor for his advice. This has really helped me.

Regards, Bart.

[pauloconnor]

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

Hi Guys, I've been having trouble with my hannsg monitor for about a month, it started by flickering on and off for about 5 minutes when the monitor was first turned on, after the 5 minutes it was perfect, occasionally the picture would be distorted but once the monitor was turn off and on again the screen would return to normal.

The monitor stopped working completely this week and will not power up at all, I had a look at the boards and there seems to be a burnt out fuse on the back of the main PSU board. if someone could advise me on where to get replacement parts I would really appreciate it. I've attached pictures of the board with the area circled, you can see quite clearly that the board around the affected fuse (at least I think it's a fuse) is darker. I was thinking that the cap on the opposite side could be the cause, perhaps dried out, it's looks perfect though.

[pauloconnor]

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

<a href="https://www.flickr.com/photos/paul_oconnor_photography/14400275010" title="board2 by Paul O&#x27;Connor, on Flickr"><img src="https://farm4.staticflickr.com/3911/14400275010_7fc40d9309_h.jpg" width="1161" height="1600" alt="board2"></a>

<a href="https://www.flickr.com/photos/paul_oconnor_photography/14586925145" title="board1 by Paul O&#x27;Connor, on Flickr"><img src="https://farm6.staticflickr.com/5474/14586925145_4e96837e80_h.jpg" width="1600" height="1241" alt="board1"></a>

<a href="https://www.flickr.com/photos/paul_oconnor_photography/14400523887" title="board0 by Paul O&#x27;Connor, on Flickr"><img src="https://farm4.staticflickr.com/3887/14400523887_6ddc21ade7_h.jpg" width="1600" height="1068" alt="board0"></a>

[pauloconnor]

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

Sorry about the messy post.... had a little trouble attaching the images

[jez_h]

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

Hi, wonder if anyone can help - please?

I have a Hanns G HZ281z which suddenly stopped turning on (no sound or anything - just switched itself off one day). I've taken it apart and can't see any problems (like bulging capacitors or anything).

I can post photos of the inside if that helps?
Is it likely to be one of the internal fuses that has blown?
Any ideas, help or advise really appreciated!

[Lumberjack777]

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

If the power board looks like the one pictured above. Try replacing the 3 caps that are circled in red. (in my picture) That fixes them most of the time. These caps are not bulged. They get dried up inside.

[jez_h]

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

If the power board looks like the one pictured above. Try replacing the 3 caps that are circled in red. (in my picture) That fixes them most of the time. These caps are not bulged. They get dried up inside.

Thanks. the board looks a bit different. Any ideas please?[/URL][/IMG]

[Lumberjack777]

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

Please don't post pictures inline, it slows the loading of the page. Use "Go Advanced" and "Manage Attachments" to post pictures.

Wow. That's one board? Power supply and inverter? I have never seen one that big before.

Looks like we are going to have to track this down the old fashioned way. You need to check the DC voltage on the 2 leads from that big capacitor circled in blue. Should be around 170v I think. ******Be careful. That is high voltage. ***** I usually brace my elbows on the table when checking those.

I'm suspecting it's your startup capacitor circled in red.

So first we are making sure you are getting voltage to that big capacitor. If so, I'd probably start by replacing that startup capacitor.
Others can help you do more diagnostics if you need it.

[selldoor]

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

I thought that start up cap looked a little rounded on top.
If you want to start testing something a little less exciting there are two fuses I can see - they are red rectangular box ones one is in the bottom right corner
and going straight up another one in the corner wher the board expands.

There should be another near the mains plug but cant tell which it is
possibly the black cyclinder that is on end - check if that has a F*** designation on the board beside it.
Or is could be the black rectangular box in the same area - what does it say on top of that?
Whole board needs a good dusting - brush and vacuum.

[jez_h]

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

Thanks both - appreciate the help. I'll have a look over the weekend.

(and sorry about posting pictures in the thread directly! Newby error I guess!)

[budm]

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

OK, so yes, we need to find out if you do have about 330VDC on the two legs of the main filter cap (around 170VDC for USA, around 330VDC for EURO).
You can also try heating those two caps I marked with hair dryer for 2~3 minutes before plugging the board into the out to see if the standby voltage will come back. We also need good clear straight shot of the bottom side of the board and also in 4 sections (closed up) so we can clearly see the traces.

[Lumberjack777]

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

I see budm. He's from the UK. Not US. His voltage will be much higher at the main filter cap. Thanks for catching that!

I'm headed off to have my eyes checked. J/K

[jez_h]

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

Many thanks for all the replies. I've uploaded some more photos to see if they help (including close ups of some of the caps you've mentioned).

yes from the UK so should be 330VDC I guess.

I've checked those 3 fuses and all seem good (zero resistance).

Budm - I assume I'd need to remove the caps from the board before heating them with the hairdryer?

Can't see any bulging - but hopefully it's more clear in the latest photos (if I can get them uploaded).

Selldoor - not certain which "black rectangular box " you're referring to please?

Lumberjack777 - I haven't tried tracing yet - as I've had to disconnect the board to check the fuses.

Again, really appreciate the time you guys are taking to help!


...it's throwing errors when uploading my photos - so will try and post later

[selldoor]

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

Pictures need to be jpg and less than 3mb ( sometimes I think that is in total if you are trying to upload a few all together) try one at a time.

I will add a pic to this showing the possible fuses check back for it

Nooooo dont remove caps to warm them up

[jez_h]

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

Think that explains it - the pics are 6mb!

Any idea about getting them down to 3mb please?

Thanks about warming them up. Guess I'll be borrowing the Mrs's hairdryer then!