Hanns_G HG281D with flashing/blinking screen problems

[herbal718]

Re: Hanns_G HG281D with flashing/blinking screen problems

I'm sorry to bump this old thread. I have the same exact problems as Barq posted, same monitor. However my monitor is past it's warranty phase. I was wondering if any moderator could send a message to Barq asking if he knows what they fixed.

I did have the monitor apart and inspected all the caps, they are in good condition and I suspect they are dry caps. I need to run some voltage tests on them as soon as I can I'll try to get the info here, again I'm sorry that I bumped this old thread instead of starting my own, as the symptoms matched exactly my own I figured it would be a good to continue the discussion in this thread. I will try and get all the info and pictures in the coming days up in this thread, if that's an issue I'll start a new one.

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

Well guys Im back. I decided to call Hanns-G and they are going to honor the warranty on parts and labor even though I have opened the case and fiddled around. I was amazed by thier willingness to help me when I explained that I thought it was not under warranty anymore and I was wondering wahat parts would cost they took my info and decided to honor the warranty which was actually 3 years not 2 as I thought.. So I am going ot send it back and get it fixed as I have way to many other alternative energy projects going on to make time for this. I wil however, be sure to post back and let you know what they came up with as far as what was wrong. btw I told them that i had opened it and that I had worked in a tv shop when I was young and was going to fix it so they wrote the rma up as me having been a tech. so warranty not voided for opening the case. A trick some one might want to remember in the future. All in all I they were anxoius to keep me as a customer in the future and I was surprised at the courtisy. If I get it fixed and all I pay is shipping I will defenately recommend them to other in the future. I like corps. that care about customer satisfaction. Thanks for all the help from what I can see you guys are busy with a crud load of others with bad viewsonics. You guys are the best.

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

Will do. I cant get to it tonight but I want to know exactly what it is too.

[retiredcaps]

Re: Hanns_G HG281D with flashing/blinking screen problems

However while I have it apart I see no reason not to just replace all the caps on the power supply as they seem easy to get to and are larger and I dont want to take it apart again later because one of them failed. Also, I will test the caps on the logic board on the side where the hdmi port is. I may just order all the caps on the logic board and get rid of those too.

I think to replace all your caps (inverter, power, and logic) would probably cost around $20 from digikey. For me, I would spend $20 to try and fix a 28 inch monitor.

If you choose to recap everything, may I suggest recapping just the logic board and retesting for flashing on/off? I would like to find the root cause. Then, afterwards, you can recap everything else.

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

btw It used to always make a pop/click sound when I turned it on so Im pretty sure its a cap some where and it just dont show.

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

Hey guys thanks for all the help. Im afraid I have to put it on the backburner today as I am working on my van today. Tonight I will do what I can to get it flashing then I will test voltages again to be sure as it wasnt flashing then. Retiredcaps I think you are right. However while I have it apart I see no reason not to just replace all the caps on the power supply as they seem easy to get to and are larger and I dont want to take it apart again later because one of them failed. Also, I will test the caps on the logic board on the side where the hdmi port is. I may just order all the caps on the logic board and get rid of those too. If it fails this has been a great learning experience for me. I will also be looking for broken screen monitors like mine to buy for parts. But I will do all the testing first. Be back later.

[PlainBill]

Re: Hanns_G HG281D with flashing/blinking screen problems

Good points, retiredcaps. It had slipped my mind, but one of the first monitors I repaired (A VP211b, if I recall) had a flakey signal card. It wouldn't run at maximum resolution when it got warm. I never did solve that one, but the signal board from another VP211b worked fine. There were over a dozen surface mount electrolytic caps on the signal card, and I didn't care to try and replace all of them.

PlainBill

[alexanna]

Re: Hanns_G HG281D with flashing/blinking screen problems

ok heres the volatages

Something is really bugging me about your monitor, when you are using HDMI your back lights are flashing on and off. But you indicate that all the voltages are steady.
When you measured the voltages where the back lights flashing?

[retiredcaps]

Re: Hanns_G HG281D with flashing/blinking screen problems

Ill check back tommorrow and see what else you got for me, guess I need a whole new logic board?

Most here at badcaps try to do component level repair versus board swapping. It is cheaper and you get way more satisfaction. It is too early to say you need a replacement logic board.

I do have one idea. Since you are an electrican, you may have access to a multimeter than can measure capacitance?

See why you may need one by reading PlainBill's explanation at

https://www.badcaps.net/forum/showpo...13&postcount=7

"If memory serves, a year or more ago someone substituted a higher value cap in the power supply of his signal card and discovered it wouldn't work at the higher resolutions. Installing the proper value corrected that."

It might be possible that one or more of the caps on the logic board is not measuring up to their rated uF. For example, a 330uF 25V cap might only measure 100uF which *might* be causing the lcd not being able to support the higher resolutions.

We know the lcd is rock solid at the low resolution BIOS screen and we know it is rock solid for VGA input.

I, however, cannot begin to tell you which caps might be in th HDMI "circuit path". It is possible that certain caps or components are separated. That is, one for VGA and one for HDMI.

The caps on the logic board are normally not low ESR caps (more likely general purpose). So if you want to take a chance, I might recommend using Panasonic FC caps for replacements. FC are "entry level" low ESR caps, but I think they should work fine in the logic board.

Also the sparkle comment was mentioned in this post and resolved by replacing the caps on the logic board. See

https://www.badcaps.net/forum/showpo...5&postcount=51

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

Well darn ater restarting it a couple times it went back to not working and then I reset it to lower than HD setting and restarted and it works fine. so I think you figured it out. must be HD logic circuit? Ill check back tommorrow and see what else you got for me, guess I need a whole new logic board?

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

WEll guess what? I set up a dual scren display and turned the res down on the LCD and restarted. It quit flashing and hasnt flashed since. I turned back up to 1900x1200 and its not flashing. wierd. Its like by turning the res down it recalibrted or something. Im not thinking its fixed though. Im gonna cut a hole in the back of the case for a small fan with a good filter on it so I dont blow dust in to it. and hole so I can get to it and blow it all clean.

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

ok, I have been running it at 1280x1024 while testing so Ill try lower resolutions but too low and it wont work. brb

[retiredcaps]

Re: Hanns_G HG281D with flashing/blinking screen problems

just checked my adapter is capable of 2560x1600

For fun, can you set the HDMI adapter to 1280x1024 and see if the display is stable for 60 seconds?

If yes, go up on "notch" in the resolution setting until the lcd blinks off/on.

Conversely, if it flashes on/off at 1280x1024, can you go down to the next lowest resolution?

I'm trying to see if the HDMI is stable at certain resolutions or not. We know at the BIOS screen, the HDMI port works reliably.

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

just checked my adapter is capable of 2560x1600

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

ok ran it with vga cable, No Flashing screen stable. As far as HDMI max res, Im not sure anymore but its much higher than 1920x1200. I can set this vga monitor to 2048x1536 .

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

I have 2 4hd 4870's in or out of crossfire it still flashes. It is capable of much higher resolutions than this monitor can support. I run the monitor at 1920x 1200 and the same with vga I will do the test but I know it wont flash. The monitor Im on right now is vga and it doesnt flash. remember one thing if this matters at all. My video cards have dual dvi ports and anything else is done by an ati adapter dvi-hdmi, dvi-vga. One other thing, I always thought the video from the bios is analogous till the OS kicks in? ok gonna do the test BRB

[retiredcaps]

Re: Hanns_G HG281D with flashing/blinking screen problems

OK I tired that and the bios screen did NOT flash on and off with the HDMI cable

1) Okay, one other test. Hookup Vista computer using VGA. Set the adapter to the highest resolution (tell us what it is). Leave it on for 5 minutes. Does it flash on/off?

2) What is the highest resolution on the adapter for the HDMI port?

After this test, I have one theory and will see if others agree or not.

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

OK I tired that and the bios screen did NOT flash on and off with the HDMI cable

[Barq]

Re: Hanns_G HG281D with flashing/blinking screen problems

ok I will after dinner.

[retiredcaps]

Re: Hanns_G HG281D with flashing/blinking screen problems

Was there a result for this test?

Hookup via HDMI, put your computer into BIOS setup mode and leave it on that screen for 5 minutes. Does the lcd flash on/off?