Hanns-G HU196D monitor not coming on.

[Bampot]

Hi Folks……. I think it is a fantastic site and service you have here and I hope you are rewarded with a long and happy life. From reading a few threads and doing a bit of research I think I can say I may have the symptoms of a bad-cap. My 19” Hannstar HU196D monitor began just not coming on straight away and the green light would flash and the speakers would give a short crack sound in unison (the sound speakers often make when you turn a device off) so I assumed the monitor was switching itself on and off because the screen was failing to come on. The problem got progressively worse until it would take several minutes to start. I found if I left the power on and came back later it would start quicker and I put this down to everything and the room warming up a bit. Eventually I was warming it up a little with a fan heater before it would start. Now there are no signs of life at all.

My replacement monitor is a very similar Hanns-g HC194D and it has also started doing the exact same thing, so I'm hoping I can fix at least one of them. I'm a complete novice to this and so I was wondering if anyone could give me a clue as to which capacitors would be the best candidates for replacing first. There are no signs of leakage or bulging on any of the capacitors and it all looks clean and new with no sight or smell that anything has ever been overheated. Could the problem be something other than a capacitor?

On looking for replacements I discovered that not all capacitors are the typical cylindrical shape, so could my problem be something other then the obvious capacitors on the boards? All the cylindrical ones are either Elite or Lelon, except perhaps the great big one as I can't see a name on it. By the way the big one is marked as 400v and so am I right in believing I need to treat it with a bit of respect when it is charged? Should I check it is discharged and how would I do that? A few decades ago before I knew what a capacitor was I got a kick from a TV and I have no desire to be reminded how that felt.

Regards
Brian.

[retiredcaps]

Re: Hanns-G HU196D monitor not coming on.

The problem got progressively worse until it would take several minutes to start. I found if I left the power on and came back later it would start quicker and I put this down to everything and the room warming up a bit. Eventually I was warming it up a little with a fan heater before it would start.

First of all, those are great clear well lit pictures. It helps a lot when remote troubleshooting.

The symptoms you describe above sound like dried out caps with high ESR (ohms). As the the monitor warms up, the cap's ESR drops and the monitor works.

There are no signs of leakage or bulging on any of the capacitors and it all looks clean and new with no sight or smell that anything has ever been overheated.

Capacitors die from age, heat, and shoddy build quality. Capacitors DO NOT have to be visibly bloated in order to bad. They can be out of tolerance uF (a 1000uF measures 20uF) and/or have high ESR (ohm). A multimeter will be insufficient to test for ESR. For that you need an ESR tester which costs between $50 and $300.

On looking for replacements I discovered that not all capacitors are the typical cylindrical shape, so could my problem be something other then the obvious capacitors on the boards?

The blue caps rarely fail.

By the way the big one is marked as 400v and so am I right in believing I need to treat it with a bit of respect when it is charged? Should I check it is discharged and how would I do that?

If you live in the USA and depending if the monitor has PFC or not, DC voltages at the big cap can reach 360 to 370V DC. Most big caps in the lcd monitor discharge themselves in about 60 seconds. If you have a multimeter, you can measure across the big cap to see if it is discharged before working on the monitor.

Steps to take.

1) If you have a multimeter, measure the secondary DC voltages at the 4 pin connector at the bottom of your picture. At least one of those voltages should be stable and steady 5V DC. Report your voltages especially when the monitor is not working.

2) If you don't have a multimeter, then members will recommend that you replace all the capacitors on the power board as Elite and Lelon don't have a stellar reputation. Members here like Panasonic FR, FM, and FC in that order.

PCBONEZ will if I don't explain that when replacing caps, you want the same or more ripple and the same or less ESR (ohms) as per

https://www.badcaps.net/forum/showpo...47&postcount=3

[PlainBill]

Re: Hanns-G HU196D monitor not coming on.

Good pictures make it easier for us. Thanks for these.

I don't see any signs of bad caps, but the symptoms you describe are classic for bad caps. Also, there are some signs of components overheating, so let's make some rudimentary tests before replacing anything. These tests will require use of a DMM; if you don't have one you have a choice - you can go in 'blind', or you can purchase one. Frankly, the odds are pretty good that a cap replacement will do the job.

These tests will be done with power on, disconnect the signal card before connecting power. I've marked up the picture of the top of the power supply. Be very careful not to touch the heat sink circled in red. Once power is disconnected there should be no danger in touching that or the large cap.

Set your DMM to the 20 volt DC range. Measure the voltage from the grounding tab circled in black (lower left corner) to either of the leads circled in orange. Do the same with either of the leads circled in yellow. One of those readings should be about 5 volts, the other should be higher, about 12 volts would be my guess.

Now disconnect the power, wait a few minutes, connect the signal card to the power supply and repeat the tests. If you no longer get voltage readings, or they fluctuate, it's time to identify the caps.

I've circled the caps on the power supply that should be replaced in blue. For each of those, record the capacitance, the voltage, and the diameter. Also record the height of the highest cap, or if the transformer (the boxy object wrapped in yellow tape) is taller, record that height.

This thread has a procedure for selecting replacement caps. After you have done that, post the information you collected in the above paragraph and your selected caps. Someone will verify your choices.

PlainBill

[Bampot]

Re: Hanns-G HU196D monitor not coming on.

Hi retiredcaps, and thanks for your comprehensive reply.

I’m afraid I’m not failure with most of the technical stuff and wouldn’t be sure about checking voltages and have no clue about PFC and ESR or ripple etc. As far as I got was that I need to match the uF value for my replacement capacitors and the voltage needs to be the same or higher. The soldering job itself is well within my capabilities.

I’m in the UK and I’ve got a few links to suppliers from other threads here. I’ll certainly be trying to get quality items. I’ll do a bit more reading and study of PCBONEZ advice and see what I can find here in the UK and then post back for conformation that I’ve found the correct capacitors.

I take it the power board is the bigger one of the two. I see 10 caps on there and I don’t mind replacing them all as a first step. Could the big one be involved and is it worth just replacing that as well? What about the smaller board, could any of them be involved in my problem and would you advise just replacing all 7 of them while I‘m at it?

Thanks
Brian.

Wow, thanks PlainBill, you got in there while I was replying to retiredcaps. Let me read your post a few times and reply.

[Bampot]

Re: Hanns-G HU196D monitor not coming on.

I did manage to find my old DMM and after replacing the battery remembered that it had developed a faulty display. So I’m just going to forget about testing and go for replacing the caps. I’m out of my depth with the testing anyway and don’t really have the time or enough free brain cells to get involved at the moment.

Thanks for reminding me about the height of the caps PlainBill, I might have overlooked that important detail. When I started looking for matching caps I discovered just what a selection there is and what a pain it was going to be to hunt down what I want. I then noticed that badcaps.net do international orders, so what better way to get them.

There are three different caps on the power board and here are all the numbers on them and their size.

470uF 25v - ES(M) 105c (c )0640 - dimensions 10 x 17mm
1000uF 10v - ES(M)105c (c )0618 - dimensions 10 x 17mm
100uF 50v RXK105c A604(m) - dimensions 8 x 11mm

Would this one do for the 470uF 25v
https://www.badcaps.net/store/produc...products_id=72

Which of these two would be best to replace the 1000uF 10v
https://www.badcaps.net/store/produc...products_id=68
https://www.badcaps.net/store/produc...roducts_id=164

I can’t see a suitable one on BadCaps Master List for the 100uF 50v - Is there another stock list that I’m missing?

I hunted some down in the UK - would any of these be suitable?
http://uk.rs-online.com/web/p/aluminium/3654284/
http://uk.rs-online.com/web/p/aluminium/2286903/
http://uk.rs-online.com/web/p/aluminium/5261597/
http://uk.rs-online.com/web/p/aluminium/7083894/

Thanks again for your time guys.
Brian.

[PlainBill]

Re: Hanns-G HU196D monitor not coming on.

https://www.badcaps.net/store/product...products_id=72 is excellent for the 470uF 25v.

I'd go with this to replace the 1000uF 10v: https://www.badcaps.net/store/product...products_id=68

And either of these http://uk.rs-online.com/web/p/aluminium/5261597/
http://uk.rs-online.com/web/p/aluminium/7083894/ would work for the 100uF 50v.

PlainBill

[retiredcaps]

Re: Hanns-G HU196D monitor not coming on.

I then noticed that badcaps.net do international orders, so what better way to get them.

If you are going to make an international order, you might as well take apart the other Hanns monitor that might be dying and make a capacitor list/order to save yourself future shipping costs.

[Bampot]

Re: Hanns-G HU196D monitor not coming on.

Thanks ever so guys…. I can now be confident I’m getting the right parts and that I’m heading in the right direction by changing the capacitors. Of course you are right retiredcaps and I’ll have a look in the other monitor before I order anything. Its going to be at least next week now before I can get round to that as I have already spent too much time on this over the last couple of days. I will of course come back and updated this thread with reports of how I got on.

Thanks.
Brian

[Bampot]

Re: Hanns-G HU196D monitor not coming on.

Hi Guys……well I managed to get new capacitors from the guy in the back of an old TV repair shop just 2 hundred yards from my house - go figure. Unfortunately it did not work for the monitor in question here, but I did have complete success with my replacement monitor that was starting to play up as well. I guessed I was on to a possible winner with this monitor as soon as I took it apart - see the attached photo. Out of 11 capacitors 8 were badly bulging on top and one had burst at the bottom! Hard to believe it was still working.

Anyway…….I replaced all the caps on the power board of the first monitor and it made no difference at all, still dead. I'm starting to think that perhaps there was a second fault that finally ended the life of this monitor, as now not even the power light shows on the on/off switch. I did discover if I switch the power on and off at the wall a few times I can get the power light to come on green for a few seconds, and sometimes it will flash red and/or orange. Also occasionally the whole screen will light up pure white for a second or two. And just a couple of times I got wide vertical bands that flashed and moved and were mostly white but did have some texture to them.

Does any of those symptoms point to another possible fault? Would you recommend replacing the caps on the smaller board? The monitor does have both VGA and DVI input and I've tried both but it makes no difference.

I'm just chuffed I managed to fix one of them.
Thanks, Brian

[retiredcaps]

Re: Hanns-G HU196D monitor not coming on.

Does any of those symptoms point to another possible fault? Would you recommend replacing the caps on the smaller board?

At this point, you will probably need a multimeter to proceed.

[PlainBill]

Re: Hanns-G HU196D monitor not coming on.

Hi Guys……well I managed to get new capacitors from the guy in the back of an old TV repair shop just 2 hundred yards from my house - go figure. Unfortunately it did not work for the monitor in question here, but I did have complete success with my replacement monitor that was starting to play up as well. I guessed I was on to a possible winner with this monitor as soon as I took it apart - see the attached photo. Out of 11 capacitors 8 were badly bulging on top and one had burst at the bottom! Hard to believe it was still working.

Anyway…….I replaced all the caps on the power board of the first monitor and it made no difference at all, still dead. I’m starting to think that perhaps there was a second fault that finally ended the life of this monitor, as now not even the power light shows on the on/off switch. I did discover if I switch the power on and off at the wall a few times I can get the power light to come on green for a few seconds, and sometimes it will flash red and/or orange. Also occasionally the whole screen will light up pure white for a second or two. And just a couple of times I got wide vertical bands that flashed and moved and were mostly white but did have some texture to them.

Does any of those symptoms point to another possible fault? Would you recommend replacing the caps on the smaller board? The monitor does have both VGA and DVI input and I’ve tried both but it makes no difference.

I’m just chuffed I managed to fix one of them.
Thanks, Brian

This "get new capacitors from the guy in the back of an old TV repair shop" is a red flag; I'm surprised retiredcaps didn't catch it. It brings up several more questions.

What brand and series did you get? Did you replace ALL the caps, or only those that are obviously bloated?

I agree with retiredcaps - get a DMM. A few minutes will give us a wealth of information.

PlainBill

[retiredcaps]

Re: Hanns-G HU196D monitor not coming on.

This "get new capacitors from the guy in the back of an old TV repair shop" is a red flag; I'm surprised retiredcaps didn't catch it.

3.5 hours of sleep last night/this morning.

[Bampot]

Re: Hanns-G HU196D monitor not coming on.

Hi Guys, thanks again for your time.

I think I'm going to leave the old monitor for now seeing as how its replacement is fixed and working great again. I've spent so much time on this already it would probably have made better financial sense just to have bought a new monitor.

I appreciate what you are saying about the quality of the caps and I must confess I did not recognize any of the manufactures' names on them and I can't now recall what they were. On the still dead monitor I did change all the caps on the power board, but with the one now working again I had to leave a couple of really small ones I did not have replacements for - they did look fine.

I retire in ten years time (hopefully) and I would love to get myself a decent workdesk and really learn and play with electronics - I've always wanted to know more about that stuff. Perhaps I'll fix that monitor then if there is still a need for such things as personal PCs.

Kind Regards
Brian.

[Haran]

Re: Hanns-G HU196D monitor not coming on.

Hi Bampot, i'm here to ask you a favor would you please let me know the values of the following smt resisters on the power supply closes to the FET
R819
R818
R817

i really appreciate your help thank you in advance god bless
Haran

Hi Folks……. I think it is a fantastic site and service you have here and I hope you are rewarded with a long and happy life. From reading a few threads and doing a bit of research I think I can say I may have the symptoms of a bad-cap. My 19” Hannstar HU196D monitor began just not coming on straight away and the green light would flash and the speakers would give a short crack sound in unison (the sound speakers often make when you turn a device off) so I assumed the monitor was switching itself on and off because the screen was failing to come on. The problem got progressively worse until it would take several minutes to start. I found if I left the power on and came back later it would start quicker and I put this down to everything and the room warming up a bit. Eventually I was warming it up a little with a fan heater before it would start. Now there are no signs of life at all.

My replacement monitor is a very similar Hanns-g HC194D and it has also started doing the exact same thing, so I'm hoping I can fix at least one of them. I'm a complete novice to this and so I was wondering if anyone could give me a clue as to which capacitors would be the best candidates for replacing first. There are no signs of leakage or bulging on any of the capacitors and it all looks clean and new with no sight or smell that anything has ever been overheated. Could the problem be something other than a capacitor?

On looking for replacements I discovered that not all capacitors are the typical cylindrical shape, so could my problem be something other then the obvious capacitors on the boards? All the cylindrical ones are either Elite or Lelon, except perhaps the great big one as I can't see a name on it. By the way the big one is marked as 400v and so am I right in believing I need to treat it with a bit of respect when it is charged? Should I check it is discharged and how would I do that? A few decades ago before I knew what a capacitor was I got a kick from a TV and I have no desire to be reminded how that felt.

Regards
Brian.

[Haran]

Re: Hanns-G HU196D monitor not coming on.

Hi Bampot, hi a have sentimental value on my Hanns G monitor and your power supply could fix mine if you are willing to sell the power supply board alone to me how much will charge? please contact me

Haran

Hi Folks……. I think it is a fantastic site and service you have here and I hope you are rewarded with a long and happy life. From reading a few threads and doing a bit of research I think I can say I may have the symptoms of a bad-cap. My 19” Hannstar HU196D monitor began just not coming on straight away and the green light would flash and the speakers would give a short crack sound in unison (the sound speakers often make when you turn a device off) so I assumed the monitor was switching itself on and off because the screen was failing to come on. The problem got progressively worse until it would take several minutes to start. I found if I left the power on and came back later it would start quicker and I put this down to everything and the room warming up a bit. Eventually I was warming it up a little with a fan heater before it would start. Now there are no signs of life at all.

My replacement monitor is a very similar Hanns-g HC194D and it has also started doing the exact same thing, so I'm hoping I can fix at least one of them. I'm a complete novice to this and so I was wondering if anyone could give me a clue as to which capacitors would be the best candidates for replacing first. There are no signs of leakage or bulging on any of the capacitors and it all looks clean and new with no sight or smell that anything has ever been overheated. Could the problem be something other than a capacitor?

On looking for replacements I discovered that not all capacitors are the typical cylindrical shape, so could my problem be something other then the obvious capacitors on the boards? All the cylindrical ones are either Elite or Lelon, except perhaps the great big one as I can't see a name on it. By the way the big one is marked as 400v and so am I right in believing I need to treat it with a bit of respect when it is charged? Should I check it is discharged and how would I do that? A few decades ago before I knew what a capacitor was I got a kick from a TV and I have no desire to be reminded how that felt.

Regards
Brian.