Hanns-G HG281D, LCD Monitor no power

[selldoor]

Re: Hanns-G HG281D, LCD Monitor no power

FC's are good enough - problem mentioned before see post 104/105

[MicroBell1]

Re: Hanns-G HG281D, LCD Monitor no power

I've uploaded a few pics (sorry for quality) before I order the parts but can someone confirm that some of these caps look like they were replaced once?

The orginals I think said L-Tec but I can't make out the name of some of the others.

Asking because this unit was a replacement unit as I had trouble with the orginal monitor and had to send it in for warranty repair so I'm assuming this was a replacement item.

[Lumberjack777]

Re: Hanns-G HG281D, LCD Monitor no power

I've uploaded a few pics (sorry for quality) before I order the parts but can someone confirm that some of these caps look like they were replaced once?

The orginals I think said L-Tec but I can't make out the name of some of the others.

Asking because this unit was a replacement unit as I had trouble with the orginal monitor and had to send it in for warranty repair so I'm assuming this was a replacement item.

Those look like the originals alright. Another clue is the glue attached to the caps. Repairs don't normally add the glue back on. Only the original manufacturer uses it. I can see those very caps you need to replace in the center. They tend to dry up. And those 2 on the main board. And you should be fixed up real good.

[MicroBell1]

Re: Hanns-G HG281D, LCD Monitor no power

And those 2 on the main board. And you should be fixed up real good.

Thanks LJ7.

That would be C80 and C83 (Both 100U/16V) on the main board correct? He had a few more highlighted on the back of some of his pics but those were the ones he seamed to be working on in that link you posted and I put this monitor back together so I just need to confirm those cap ratings and locations.

C80 and C83 100U/16V http://www.digikey.com/product-detai...391-ND/2433525

Open to another choice if that one is incorrect.

[MicroBell1]

Re: Hanns-G HG281D, LCD Monitor no power

Almost forgot. Since I've been paying so much attention to getting this power issue fixed there was 1 other issue I forgot to mention about this monitor. When it starts and the bios loads there is a click sound and when windows loads it clicks again. Does not do this when changing resolutions and has done this since I got it back from Hanns-G warranty repair.

I don't remember this issue on my orginal monitor so I'm hopeing it's tied into this cap issue so it gets solved in the process or maybe it's normal and I just remember incorrectly but I thought I would mention it.

[selldoor]

Re: Hanns-G HG281D, LCD Monitor no power

Thanks LJ7.

That would be C80 and C83 (Both 100U/16V) on the main board correct? He had a few more highlighted on the back of some of his pics but those were the ones he seamed to be working on in that link you posted and I put this monitor back together so I just need to confirm those cap ratings and locations.

C80 and C83 100U/16V http://www.digikey.com/product-detai...391-ND/2433525

Open to another choice if that one is incorrect.

Yes C80 and C83 are usually the ones to change on the main board
They are 100uf16v and the ones in the digikey link will be fine.

[Lumberjack777]

Re: Hanns-G HG281D, LCD Monitor no power

Yes C80 and C83 are usually the ones to change on the main board
They are 100uf16v and the ones in the digikey link will be fine.

Thanks selldoor. I don't always make it back out here as much as I'd like to. That's the 2 on the main board budm mentioned alright.

Microbell. As far as the clicking noise goes. Lets replace those small caps in the middle of the PSU and see if everything works well. The clicking may be related to the small startup cap you are going to replace.

And last. My favorite link retiredcaps ever posted. How to solder correctly. Excellent tutorial - http://www.youtube.com/watch?v=I_NU2ruzyc4

MB. Come on back with a followup as to how the repair went. OK? Thanks. L-J-7

[MicroBell1]

Re: Hanns-G HG281D, LCD Monitor no power

MB. Come on back with a followup as to how the repair went. OK? Thanks. L-J-7

You bet LJ7. I'll be addressing this in the next few weeks and will update this post as to the outcome. Thank you guys for helping me ID the issues with this monitor! This threads been quite helpful and you guys so knowledgeable!!

[MicroBell1]

Re: Hanns-G HG281D, LCD Monitor no power

Well this just keeps getting better and better. The monitor would not come up today so I tore it apart again today to see if something came unpluged as I had it apart a day or so ago getting cap ratings.

I'm still pretty sure my issue is related to the caps on the PSU and I have them (8 on PSU 2 for LB) on the way, but discoverd a mess today on the logic board (see pics). As I stated before this monitor was already in for warranty repair for a "Fuzzy Screen" issue so I'm asumming this is their fix.

On the logic board it looks like they already replaced 3 caps judgeing by the mess they left on the board.

C80 With a 100u 25V
C83 With a 100u 25V
C69 With a 100U 25V

Now besides the mess what concerns me is the voltage regulator U7 (Img_0611). Measuring voltages this is what I got (Regulator upright-legs down pin 1-3 reading left to right)

U7 (Part# AC 84-33 06301L)
Pin1= 0V
Pin2= 2.9-3.1V (fluctuating on both Pin and Pad)
Pin3= 3.91-4.58V (fluctuating)

U8 (Part# AC 7BoL 17-18L)
Pin1= 0V
Pin2= 1.68-1.82V (fluctuating)
Pin3= 2.9-3.1V (fluctuating)

Lead power to the LB from PSU connections

CN7= Red wire 3.52-4.59V (fluctuating)
CN5= Brown wire 3.87-4.49V (fluctuating)

Now why I think it's still a power issue is because there is no stable 5V across the rail to these componets but this mess around U7 is quite questionable as I can't figure out why the middle leg (Pin2) is disconnected and the pad under it still reads (2.9-3.1V (fluctuating)) as does the non connected pin above it.

It looks like it was cut (not burned away) and the solder pad refloated to smooth it out. Is that normal? It also looks like that whole corner of the logic board under U7 is running hot judging by the discoloration on that corner of the board.

Anyway my parts won't be here till mid week due to the holiday but I wanted to get your input on this issue and suggestions on what I can do to clean up the mess these warranty repair guys left on that board and how, or should I just leave it alone once the PSU is fixed (asumming the cap replacement fix's the power up issue) and should I still replace C80 and C83 since it's already been done?

Thoughts?

*Note* After putting that monitor back together and running through the "heating up process" again it's on and working and I'm on it now....ROFLMAO
On a side note the missing U7 pin may be normal as looking through other pics in this thread they also don't look to be connected.

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

The brown "mess" on the logic board is just left over flux from when they changed the caps under the warranty repair. Doesn't help nor hurt the board in any way, so it can be left alone. If you want to clean it, you can use isopropyl alcohol.

As far as changing caps C80, C83, and C69 - that depends on what caps they used for the replacements. Judging by the color, they look like Chemicon KY or KZE to me. If not, let us know what they are. I would also suggest to replace the 3 small 10uF 16V CapXon caps (C74, C77, C8) right under the the voltage regulator - they likely got cooked.

Also that 22uF 35V small L-tec cap on the power board.

[MicroBell1]

Re: Hanns-G HG281D, LCD Monitor no power

Thanks Momaka. I could not find anything on the caps that said Chemicon but I did see the KY so that's likely them. As for that 22u/35v on the power board that's already on the list to be changed out.

I figured that "Mess" was just flux and won't deal with it unless I decide to change those caps out but I'll have to decide what to do about those other three you mentioned (C74, C77, C8) as I didn't see them being so problematic on this thread so I didn't order them for this power issue so I may wait and see what becomes of the first fix.

[Lumberjack777]

Re: Hanns-G HG281D, LCD Monitor no power

Anyway my parts won't be here till mid week due to the holiday but I wanted to get your input on this issue and suggestions on what I can do to clean up the mess these warranty repair guys left on that board and how, or should I just leave it alone once the PSU is fixed (asumming the cap replacement fix's the power up issue) and should I still replace C80 and C83 since it's already been done?

Thoughts?

The "mess" is the flux left over from their soldering. A little alcohol and a Q-tip or paper towel will clean that right up. They actually did a decent job soldering. I'd leave the ones on the main board.

The reason for the intermittent startups is because that little startup cap is probably almost dried out. Once you replace the 8 on the power board you'll be fine. Not sure about your soldering skill; but if you need to, you might wanna practice up until the caps arrive. Sincerely, L-J-7

[MicroBell1]

Re: Hanns-G HG281D, LCD Monitor no power

Not sure about your soldering skill; but if you need to, you might wanna practice up until the caps arrive. Sincerely, L-J-7

Way ahead of ya LJ7... already got my ole KA7-100 Abit mother board out to practice a bit cause it's been awhile.......lol.

[marts_8]

Re: Hanns-G HG281D, LCD Monitor no power

hi! Im new to this forum but I have been reading this thread for awhile now. I have a couple of 19" Hanspree New York that I'am trying to fix. Since Hanspree is also a brand of Hanns-G, I posted my problem here maybe you are more familiar with looking at it.

The first one, I think, has a problem with the logic board since I swapped the power board in a working unit and it was working. When i turn on the power button, it goes white then slowly goes to backlight (not totally black). I have changed one capacitor (encircled in red) already but same results.

The other one that needs fixing has a problem with the power board, I think, since I swapped its power board into a working unit and its not working. When I push the power button, it goes green for a few secs then 1 sec orange then no light then green again for a few secs then 1 sec orange. The cycle goes on and on for 20 mins until it says "No Signal Input" that's when I can only power up my computer to use it. there is no physical bloating of any caps and I dont have an ESR meter to test them.

hope someone can help...

[selldoor]

Re: Hanns-G HG281D, LCD Monitor no power

Marts8 - It is extremely annoying that you have posted in this thread regarding a 19" set that you dont give the model number of, that doesnt have any resemblance to the
monitor being discussed either in the size or either of the main board or power supply.
It will only confuse other members looking for information on either monitor.
Please start your own thread show the model number in the title and report your post to the mods for deletion by clicking on the red triangle.

[mc900fthanna]

Re: Hanns-G HG281D, LCD Monitor no power

As per lumberjacks suggestion I'm going to replace the following 8 caps on the power supply board in an effort to fix the slow power on issue (Blue LED blinks intermittently w/delay until caps are heated then poof solid blue and on) I'm having and need someone to confirm I'm getting the right caps.

Board Locations-CAP-Link to product from digikey


C406=10u/50V http://www.digikey.com/product-detai...1250-ND/356152
C603=22U/35V http://www.digikey.com/product-detai...1230-ND/356133
C606=1U/100V http://www.digikey.com/product-detai...0765-ND/285717
C605=47U/50V http://www.digikey.com/product-detai...0321-ND/266330
C707=22U/35V http://www.digikey.com/product-detai...1230-ND/356133
C108=10U/35V http://www.digikey.com/product-detai...5161-ND/245020
C111=22U/35V http://www.digikey.com/product-detai...1230-ND/356133
C114=2.2U/50V http://www.digikey.com/product-detai...0313-ND/266322

*Note* I could not find a FM or FC series for C108 so chose M series

If these choices are correct then ok. If I've chosen "unwisely" then please suggest a replacement from digikey. Thanks Gents!

So, I have a power supply that is blowing the 4A 250V fuse repeatedly. This occurs without anything connected to the power supply but the power, so i am pretty certain a problem lies there. As a first cheap step - I am going to replace the above caps and see if my results change.

I have gathered from some of the other posts here that a bad Mosfet can be a culprit - anything else that can be tested easily on this board to narrow down whats causing the fuse to blow (instantly once power is connected). I have an awesome multimeter (Fluke 9x v4) so i can measure most things fairly accurately. Thanks in advance.

[selldoor]

Re: Hanns-G HG281D, LCD Monitor no power

I would start with testing the bridge rectifier.

Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) 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

https://www.badcaps.net/forum/attach...7&d=1280167246

https://www.badcaps.net/forum/attach...6&d=1280167246

https://www.badcaps.net/forum/attach...4&d=1280167246

It will be useful if you can say a bit about yourself - skills tools etc.

[MicroBell1]

Re: Hanns-G HG281D, LCD Monitor no power

OMG what a nightmare I got myself into.

Where to start... Well the caps arrived in the mail today so I decided to go ahead with the recap job. As I told LJ7 I've spent the last few days practiceing on a few motherboards but also on a few ATX power supplys as those are single side boards which this PSU is so I was pretty much ready.

So what happens on the first cap desolder..... BAM!! Lift the solder pad breaking the trace right off the board using the needle method to open the hole. Solder was cool and solid but it stuck to the stainless steel as I spun it so I was pretty pissed and it was the first cap.

I could not believe how fast the board solder melted (less then 1 sec almost on contact) and this was using a cheap ass 20watt iron. The other boards I practiced on were not anything like that. Needless to say I screwed up two pretty bad and had to build some bridges to a few componets while checking continuity between them.

I was also suprised that several of the caps had the zig/zag pattern in the hole and the ends folded over on the bottom side which made their removal a little more difficult.

The three that gave me the most trouble I thought would be the easiest and they were C406, C707, C114. Anyway long story short after the repair was done I thought I would "Plug in the AC...hit the switch and hear the pop". I did check the 5V rail before power and it was rock solid so I asummed once it kicked the 12V-24V rails on it would pop.

Low and behold hit the power button and the DAM THING WORKED!!

So for those looking through this thread this is what fixed my issue which was "Slow startup, blue light blinks here and there and taking 5 min to 5 hours to come on and no sleep mode"

Replaced caps C406, C603, C606, C605, C707, C108, C111, C114 with quality panasonic caps from digikey.com. Fast delivery and total cost was $6.02 including shipping.

So special shout out to JL7, Selldoor, Retiredcaps, jetadm123 and momaka for all their help and to many others beforehand that went through the process as this produced the knowledge to save another HG281-D from the garbage can. Thanks Guys!!

*Note* The monitors been up and running for the last 5 hrs but I'm not entirely secure yet on those bad traces I had to redo/remake so I'll be watching them for any changes during the heat/cool cycles to make sure they don't pop loose or shift.

[retiredcaps]

Re: Hanns-G HG281D, LCD Monitor no power

Needless to say I screwed up two pretty bad and had to build some bridges to a few componets while checking continuity between them.

Good job on the repair.

If I think desoldering will be difficult due to multiple layers or lead free sholder, I check for continuity to other bigger components before I start desoldering.

I have lifted 3 or 4 pads over the last 2.5 years so I learned to check and document beforehand. It helps to have a multimeter with a fast continuity checker.

[momaka]

Re: Hanns-G HG281D, LCD Monitor no power

Congrats MicroBell1!

Yeah, I've screwed a few solder joints too over the years - in which case I just used wire or some other flexible conductor to extend the trace again. Never had problems with those fixed items again, though. If you used leaded solder, I think your joints will be fine for a long time.