Hannspree HSG1064 5 seconds on then blank screen

[PlainBill]

Re: Hannspree HSG1064 5 seconds on then blank screen

What i ment by "connecting the 20" inverter output to the 25" ccfl is that when i do this the 20" monitor shuts down after 2 seconds. The same thing happens to the 20" monitor when i just disconnect one of the ccfl tubes from the inverter and dont connect it to anything. So connecting one of the 20" inverter outputs (there are 4 since i have 4 bulbs) to one of the 25" ccfl tubes seems to be equivalent to just disconnecting one of the 20" ccfl bulbs.........thus i am not able to "test" the 25" ccfl bulbs.........this is what i ment by does not work..........

in the past i was able to use such a setup to "test" the bulbs of a monitor that did not work. If my test-monitor shut down after 2 secs then i knew that the bulb of the monitor-under-repair was bad. But in this case i am unable to test the bulbs of the 25" monitor.

So in a little while i will try and connect the 20" ccfl to the inverter output of the 25" monitor and see what happens. see if i learn anything useful or not.

Again, if we assume the bulbs of the 25" monitor are ok......what else should i look at to determine what is causing the 25" monitor to shut down. Just wondering if i can do a few things in parallel as far as trouble shooting.

Ah!! Thanks for the clarification.

You could compare voltages on the return line, but that is difficult unless you have a monitor that stays on more than a few seconds.

PlainBill

[Rtech]

Re: Hannspree HSG1064 5 seconds on then blank screen

Looks like my reply got lost.As Plain Bill says no damage should occur,so go for it....ALL 20" tubes onto the 25" Inverter,and lets know what happens...

[Welchs101]

Re: Hannspree HSG1064 5 seconds on then blank screen

Rtech, your reply did not get lost. I was just a little confused as all. Thanks for responding.

Update:
I used the 20" ccfl tubes to test the monitor and got some very interesting results. I cant figure out which bulb, if any, is bad. Rather than try to describe verbally what i did i created a picture of what i did hoping that this would better describe it (see enclosed pic).

If you guys would review the enclosed pic and let me know what you think i would be greatly appreciated. I cant figure out which bulb is bad, if any.

If you want me to try any other combinations just let me know and i will.

My first thought was bulb 3 of the 25" might be bad but in one of my tests bulb3 of the 25" was plugged in and 25" monitor did not shut off ......so i dont know what to think at this point.

Could it be something other than a bulb?

[alexanna]

Re: Hannspree HSG1064 5 seconds on then blank screen

Rtech, your reply did not get lost. I was just a little confused as all. Thanks for responding.

Update:
I used the 20" ccfl tubes to test the monitor and got some very interesting results. I cant figure out which bulb, if any, is bad. Rather than try to describe verbally what i did i created a picture of what i did hoping that this would better describe it (see enclosed pic).

If you guys would review the enclosed pic and let me know what you think i would be greatly appreciated. I cant figure out which bulb is bad, if any.

If you want me to try any other combinations just let me know and i will.

My first thought was bulb 3 of the 25" might be bad but in one of my tests bulb3 of the 25" was plugged in and 25" monitor did not shut off ......so i dont know what to think at this point.

Could it be something other than a bulb?

It's really hard on your monitor because we're not comparing apples to apples.
One other thing you should try, is to figure out a way to plug the bulbs 1 and 2 into sockets 3 and 4.
And bulbs 3 and 4, into the 1 and 2 sockets. Then repeat your test with a test bulb.
We are looking for the problem to follow the bulbs.
Al.

[Welchs101]

Re: Hannspree HSG1064 5 seconds on then blank screen

alexanna,

I would be happy to do the test. Just a little confused as to what exactly you want me to do and i think its because i have a 20" and 25" with bulbs. So if you could specify exactly what you want connected i will do the test. ie...if you want bulbs 1 and 2 of the 25" plugged into positions where bulbs 3 and 4 of the 25" are connected and similaryly bulbs 3 and 4 of the 25" plugged into the postions where bulbs 1 and 2 of the 25" are located .....i can do this.

Just specify monitor as well as bulb.....well, you get the idea.

[alexanna]

Re: Hannspree HSG1064 5 seconds on then blank screen

Concentrate on the 25” monitor, Use the 20”bulbs for testing the 25”
Al

[alexanna]

Re: Hannspree HSG1064 5 seconds on then blank screen

Please note my edit of the bulb length.
Al

[Welchs101]

Re: Hannspree HSG1064 5 seconds on then blank screen

alexanna,

not sure i understand what it is you want me to do. I am really sorry......just a little confused. Also, what edit are you referring to and how would i know where to find it.

again, sorry i dont understand ..........i am sure what you do tell me i will be going "duhhh...of course that what was ment".

[Welchs101]

Re: Hannspree HSG1064 5 seconds on then blank screen

quick note:

On the 25" monitor. There are 4 bulbs. Two at top and two at bottom. If i move the board upward, so that i can connect the two top bulbs to the "bottom" connections i wont be able to connect the bottom bulbs to the top connections..........electrical lines are just not long enough.

[alexanna]

Re: Hannspree HSG1064 5 seconds on then blank screen

I am doing my best to try to explain what to try.
On the 25” monitor plug in bulbs 1 and 2 into the 3 and 4 sockets of the 25” monitor, and plug in 3 and 4 bulbs into the 1 and 2 sockets of the 25” monitor.
Then substitute the 20” bulb one at a time into each socket of the 25” monitor
I am hoping that you will see the problem you are having follow your test bulb.
As far as the lengths of the ccfl wiring goes, Flip the panel over
You do not have to hook up the ribbon cable from the logic board to the LCD panel,Please just make sure you let any of the pins of the ribbon touch a ground.
Al.

[Rtech]

Re: Hannspree HSG1064 5 seconds on then blank screen

Looking at the thumbnails of your testing,the outcome that seems apparent, is that as soon as you have the bottom 25" bulbs(from the lower 3 diagrams shown), plugged in that is when the problem occurs.and the thing switches off,SO perhaps the voltage to those sockets on the Board is not enough to strike the 25" BUT are OK on the 20".I have just has something similar on a TV, and going over the supposed faulty Inverter transformer and the little caps on the secondaries,and the pins on the lamp sockets,with a soldering iron and a small amount of solder, lo and behold, I must have had a dry(high resistance joint) which I could not see, and it fixed the problem.....must be worth a go methinks ??

[Welchs101]

Re: Hannspree HSG1064 5 seconds on then blank screen

alexanna, good suggestion......had not thought about flipping the board over. Good suggestion. Also, i understand what it is your saying to do now.

Rtech, i also liked your comments. I will try alexanna's suggestion to collect additional data but I am hoping its not a bulb thing at all.

thanks ....i may not get to trying this today but by tomorrow for sure.

thanks.

[Welchs101]

Re: Hannspree HSG1064 5 seconds on then blank screen

ok. This morning i was able to "flip" the board and redo the tests. I have posted a picture to help explain the results.

BUt again.......its a little confusing.

Any ideas?

[alexanna]

Re: Hannspree HSG1064 5 seconds on then blank screen

ok. This morning i was able to "flip" the board and redo the tests. I have posted a picture to help explain the results.

BUt again.......its a little confusing.

Any ideas?

If I understand your test results correctly. It looks like when you replace either bulbs 1 or 2 with a test bulb, the monitor will stay on, no matter what side of the inverter they are installed in?
Al.

[PlainBill]

Re: Hannspree HSG1064 5 seconds on then blank screen

If I understand your test results correctly. It looks like when you replace either bulbs 1 or 2 with a test bulb, the monitor will stay on, no matter what side of the inverter they are installed in?
Al.

Seems to me that would indicate a problem with the wiring for the CCFLs, or possibly the CCFLs themselves.

PlainBill

[Welchs101]

Re: Hannspree HSG1064 5 seconds on then blank screen

If you look at ALL the combinations..........ALL of the bulbs at some time or another are "on"............its ONLY when bulbs 1 and 2 are connected together that there seems to be a problem. But this does not seem like a bulb problem ...........does it?

Any thoughts on what could be wrong with the wiring for the ccfls that would cause this? Again, ALL of the bulbs come on at one time or another if you look at all the combinations.

Rtech had mentioned the following:
"SO perhaps the voltage to those sockets on the Board is not enough to strike the 25" BUT are OK on the 20".I have just has something similar on a TV, and going over the supposed faulty Inverter transformer and the little caps on the secondaries,and the pins on the lamp sockets,with a soldering iron and a small amount of solder, lo and behold, I must have had a dry(high resistance joint) which I could not see, and it fixed the problem.....must be worth a go methinks ?? "

Based on this any ideas on things to try?

[alexanna]

Re: Hannspree HSG1064 5 seconds on then blank screen

Welchs101,I am sorry i can't get into alot of detail right now.
But a ccfl can light and look normal during the two second to back problem and still cause problems,an example would be to have a return wire that has only one or two strands of wire making conection.
Al

[Welchs101]

Re: Hannspree HSG1064 5 seconds on then blank screen

whats interesting to me is that for various combinations i can get all the lamps to come on and STAY on.........very interesting.

[alexanna]

Re: Hannspree HSG1064 5 seconds on then blank screen

whats interesting to me is that for various combinations i can get all the lamps to come on and STAY on.........very interesting.

From the test results you posted I think you have a problem with bulbs 1 and 2.
Here is what I think may be going on, this type of inverter was discussed in another thread. The inverter transformers are dependent on 2 ccfls because it's like a series circuit.
I think there is either a ccfl that has aged or a wiring problem causing them to require more voltage to light or stay on, and it's tripping the voltage protection. When you substitute the 20” bulb there is enough change in voltage requirement that even the marginable longer bulbs from the 25” monitor will work.
These are just my thoughts, Dose anybody else have any ideas?
Al.

[PlainBill]

Re: Hannspree HSG1064 5 seconds on then blank screen

From the test results you posted I think you have a problem with bulbs 1 and 2.
Here is what I think may be going on, this type of inverter was discussed in another thread. The inverter transformers are dependent on 2 ccfls because it's like a series circuit.
I think there is either a ccfl that has aged or a wiring problem causing them to require more voltage to light or stay on, and it's tripping the voltage protection. When you substitute the 20” bulb there is enough change in voltage requirement that even the marginable longer bulbs from the 25” monitor will work.
These are just my thoughts, Dose anybody else have any ideas?
Al.

I have a similar explanation. The CCFLs have aged to the point they are drawing additional current. By substituting a shorter CCFL, the current draw is reduced.

In either case, it is time to open the panel and check the tubes and the wiring.

PlainBill