Hanns-G HG281D, LCD Monitor no power

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

and here is the digikey cart sharing (i think this will work)
http://www.digikey.com/short/7rb0vr
Is everything in the digikey cart accurate?

Panasonic FM, FR, and FC are excellent choice of capacitors, so you are good there.
I didn't check if the sizes you picked will work for you, though - mainly because I've never repacced one of these monitors myself and I don't have a list of caps and their diameters. But if you have verified that yourself, you should be good then.

I see only one problem:
The 2x 1000uf 35v caps (P12405-ND) appear to be on back-order - and it will likely take a very long time before you get them. So you may have to pick some other brand and/or series of caps. Try:
Panasonic FR
Nichicon PW, HE, or HW
United Chemicon KY, KZE, or KZN

Also, for the 1000 uF, 16V caps (P12366-ND), it is cheaper to order 10 of them than to order 7 due to price break .

[fightforlife]

Re: Hanns-G HG281D, LCD Monitor no power

Basically, you're trying to see if the PC "sees" the monitor as connected.

Ive tested multiple PCs with different HDMI cables and one VGA cable.
None of them detected the monitor. But the monitor knows when a cable is connected oder disconnected (no signal message)

[krestic]

Re: Hanns-G HG281D, LCD Monitor no power

Wooff, that was a long thread. So, my story: +5VSB only, no PSON. +5VSB stable if the main board detached, and fluctuating +-0.25v if the main board is connected.
shorting +5VSB and PSON with 3.3K powers the power block on but there is some ticking coming from the power board 3-4 ticks per sec. Voltages are fluctating appr. +-0,3. Then the ticking slows down and after appr. a minute stopes. So does the voltage fluctuation.
Than the main board: The signal from the power button goes to RTD2120l MC, and doesn't go any further. I mean there is no outgoing signal changes when you press the power button. Could that be a problem?
All caps on main board are changed as well as smaller ones on the power board.
Appretioate any advice.

[mj2301]

Re: Hanns-G HG281D, LCD Monitor no power

Hey I looked at your soldering work and it looks bad. Some of the joints are missing a good portion of solder. You have to remember that the only thing connecting the capacitors are solder, and if the joints are missing a lot then you will run into stability issues. I had that issue with the logic board giving me lines across the screen. Once I re-soldered the joints the monitor worked perfectly fine.

[avioni]

Re: Hanns-G HG281D, LCD Monitor no power

great discussion. I replaced the 3 known to fail caps on the logic board 100uf 16v my screen was just loosing image randomly but now i must have messed something up bad i only get a red screen. i try reconnecting everything and even resoldering everything but still red screen. any ideas?

[fightforlife]

Re: Hanns-G HG281D, LCD Monitor no power

So I made some unsuspected progress with my hd281D.

long story short:
i didnt get any input on hdmi or vga with different pcs and cables.
After changing all the caps on both boards the problem persists.

Now the news:
i just got a Fire Tv Stick and tried it on the broken monitor and voila. There is a picture! Its not the best quality and the maximum resolution is 720p, but atleast there is some life.
So I tried the Stick with and without extension cord and both is working in 720p. (1080p is not supported by the monitor, it says)
When I try the same extension cord on a working pc with hdmi, there is still no input detected....

How is that possible... any ideas?`Thanks in advance

[feil]

Re: Hanns-G HG281D, LCD Monitor no power

Hello.
i hope this reads anyone^^

i have also one of the hg218d become from a friend, that was not working anymore.
i have changed all the caps on the power board and all the 470uf 16V and 100uf 16V on the logic board.

the monitor was fine working now for about 1 months and now i have the problem that hes running about 10 minutes and then he screen goes dark,
after it has cooled off, it also works for about 10 minutes and then the screen goes dark.
the power led stays blue

from what i can hear is that the lcd controller board is making noises.
but only when the screen goes dark,
before that eveythings fine and no noieses or anything.

could it be the inverter board or the caps from that?
or that i have get a bad cap somewhere else?

it would be nice if someone has an advice


and sry for my bad english,
I Am from Asutria

[Lumberjack777]

Re: Hanns-G HG281D, LCD Monitor no power

Your english is fine. I understand you perfectly.

When the screen goes dark, you'll need to shine a flashlight on it, in a dark room; and see if you can see a picture on the screen. Then it would be the inverter board or a lamp.

[feil]

Re: Hanns-G HG281D, LCD Monitor no power

Hello.
yes you see the screen and windows desktop, so inverter or lamps, should i try a new inverter board?

it would cost me about 35 dollar. or only the caps on the inverter board?

and lamps changing is that even possible?
and thanks

[Lumberjack777]

Re: Hanns-G HG281D, LCD Monitor no power

Hello.
yes you see the screen and windows desktop, so inverter or lamps, should i try a new inverter board?

it would cost me about 35 dollar. or only the caps on the inverter board?

and lamps changing is that even possible?
and thanks

Before you buy a new inverter board; you need to test and make sure it's getting the proper voltages.

Unplug the plastic connector to the inverter board. Then turn on the monitor (make sure you have video input attached). The connector has 12 holes. Using a digital multimeter test the voltages inside the connector. I have small pins soldered to my dmm leads so they fit inside. Place the black (negative) lead on a screw on the frame. And put the red (positive) lead in each of the holes. Here's my readings, with brown wire on the left side; black wire on the right side.
3.3v, 4.8v, 0v, 0v, 0v ,0v, 0v ,24.2v ,24.2v, 24.2v, 24.2v, 24.2v

The important thing is that it's getting 24 volts on those a 5 connections.

If you are getting the proper voltages to the inverter I'd probably try a cheap repair first. It's good practice.

If a lamp was bad, you'd at least get some sort of flash on the screen before the monitor shut down due to a faulty lamp (2 seconds to black)

[feil]

Re: Hanns-G HG281D, LCD Monitor no power

hello
i get the 24Volts, but im missing the 3,3 and 4,8V and from whats on the inverterboard stands, i think thats to start the inverter board.
so something on the power supply , a bad cap maybe? i have changed all of them and it was working for about 1 months.

do you maybe now what caps are for the 3,3 or 4,8 volt ?

thanks for your help.

[Lumberjack777]

Re: Hanns-G HG281D, LCD Monitor no power

I'd have to take the monitor apart. I just have the back cover off. Sorry.

If you can, try and trace the 3.3v and 4.8 circuit back and see what components (or caps) are in that circuit. I'm really not an expert in circuits. Maybe an expert like budm or another can help you trace that.

Until then, I'd check for faulty solder connections. Sometimes they will last for a few weeks or a month and then give out if they are faulty.

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

i have also one of the hg218d become from a friend, that was not working anymore.
i have changed all the caps on the power board and all the 470uf 16V and 100uf 16V on the logic board.

the monitor was fine working now for about 1 months and now i have the problem that hes running about 10 minutes and then he screen goes dark,
after it has cooled off, it also works for about 10 minutes and then the screen goes dark.

What brand and series of capacitors did you use for the recap. I see some new caps on the power board that I cannot identify as one of the known good Japanese brands. If you used cheap caps, it is possible that this could be the cause of your problem again, even though the symptoms are different.

[feil]

Re: Hanns-G HG281D, LCD Monitor no power

What brand and series of capacitors did you use for the recap. I see some new caps on the power board that I cannot identify as one of the known good Japanese brands. If you used cheap caps, it is possible that this could be the cause of your problem again, even though the symptoms are different.

hello. most of them are jamicon caps, und some yaego.
i had the jamicon before in other satelitte receiver and no probs with them.

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

@ feil: Yageo = Teapo, and Teapo are quite unreliable, especially in hot environments.

Sat receivers and set-top boxes usually don't run as hot as LCD monitors, so that's why those Jamicon and Yageo caps may work fine there. But this particular monitor (HG281D) is known to run hot, so I would recommend you do it with high-quality Japanese caps. Panasonic FM and FR are common online, among other brands. Probably best to avoid eBay auctions with sellers from China and HK, except for seller egekecu.

[Wester547]

Re: Hanns-G HG281D, LCD Monitor no power

^ May want to avoid egekecu as well, based on this:

http://www.ebay.com/itm/12-Pcs-Nichi...item439b7f07ef

I think those Teapo are actually resleeved G-Luxon with that X-shaped vent. G-Luxon aren't very good either, though...

[feil]

Re: Hanns-G HG281D, LCD Monitor no power

i have now orderd some panasonic caps, and i change them when tehy are here and tell you if it has worked.
thanks so far for the help.

[feil]

Re: Hanns-G HG281D, LCD Monitor no power

now i have changed the caps on the power supply with panasonic caps, but after some minutes it also gos dark, and makes noises^^

could it also be some caps on the logic board? because i have changed there some too,
and i also could try to change the caps on the inverter.
and if i turn it off and on, it works for abaout 30seconds to 1 minute then dark again

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

^ Yes, the caps on the logic board need to be replaced too. They run really hot next to those linear regulators, and if they are not a good brand, they can die quickly.

[feil]

Re: Hanns-G HG281D, LCD Monitor no power

i have now replaced them too, and for now its working.
i also have added two 40mm fans so thaht they can blow some air up in there^^
i hope that his now working for longer than 1 month^^

thanks @ all for your help.

regards
clemens