hi,
i have a strange problem.
i disassembled my benq 567s to and put it on my ohp. the only thing, the screen does when i turn it on is a short flashing
then a few seconds nothing after that it flashes again and so on. no real picture gets displayed. i reassembled it, because
it thought that i might have broken it, but when assembled it works fine.
what i haven't done (when it was disassembled) was to ground the power-supply with the display-controller and to the circuit
board which is directly connected (with flexible cables) to the screen. another thing i was unsure of, were the polarization
sheets. i removed the aluminium frame to seperate the screen from the backlight. between the screen and the backlight were
some of these polarization sheets and filter sheets, which i left in the backlight-case because i thought that i won't need
them for first tests. are they that important, that i won't get a picture without them ?
but then why do i see the screen flash (in regular intervalls of a few seconds) ?
thanks in advance for anyone that helps me out 🙂
cu,
cyberdemon
btw.: could someone please give me the link to the homepage, where that nec screen got disassebled, maybe they
say something abount grounding and the polarization sheets
i have a strange problem.
i disassembled my benq 567s to and put it on my ohp. the only thing, the screen does when i turn it on is a short flashing
then a few seconds nothing after that it flashes again and so on. no real picture gets displayed. i reassembled it, because
it thought that i might have broken it, but when assembled it works fine.
what i haven't done (when it was disassembled) was to ground the power-supply with the display-controller and to the circuit
board which is directly connected (with flexible cables) to the screen. another thing i was unsure of, were the polarization
sheets. i removed the aluminium frame to seperate the screen from the backlight. between the screen and the backlight were
some of these polarization sheets and filter sheets, which i left in the backlight-case because i thought that i won't need
them for first tests. are they that important, that i won't get a picture without them ?
but then why do i see the screen flash (in regular intervalls of a few seconds) ?
thanks in advance for anyone that helps me out 🙂
cu,
cyberdemon
btw.: could someone please give me the link to the homepage, where that nec screen got disassebled, maybe they
say something abount grounding and the polarization sheets
TN (twisted neumatics) TFT LCD's only work with polarizers, because they use polarizing for adjusting the amount of light that goes through. They do that by actually twisting the liquid crystals.
Check if your LCD has films glued to both sides of the glass. If so then the needed polarizing films are there, if not I'll eat my OHP( veeeeeeeeery unlikly).
Cyberdemon :
See my site. I explain (in french) how to dismantle the FP567s.
http://kolimavp.free.fr/
With my 'portable computer', the LCD don't work : Maybe a 'ground' problem.
rapsac and mhelin:
I don't really understand ....
There's a film glued on the front side of the LCD.
On the other side the films can be removed.
Must we keep them ???
See my site. I explain (in french) how to dismantle the FP567s.
http://kolimavp.free.fr/
With my 'portable computer', the LCD don't work : Maybe a 'ground' problem.
rapsac and mhelin:
I don't really understand ....
There's a film glued on the front side of the LCD.
On the other side the films can be removed.
Must we keep them ???
Actually the TN TFT need two polarizers, the front and the back (backligh fils is horizontal and the fron vertical, so no light goes through the panel without crystals). The crystals actually "modulate" the polarization of the light, a subpixel is light when the crystal twistes the polarization of the light 90 degrees. So it should work whichever way, but there may also be other filters (front glass, IR etc.).
exactly,
on the frontside of the display ist a
transparent green polarizing film (i think ?)
when removing the backlight, the other filters
are just squeezed in between the backlight
and the back of the display (not glued, etc.).
so do you think that i should put the polarizing
sheets, filters, etc. also onto the ohp, or should
the display itself (with the front polarizer) be
enough ?
i still don't understand, why it flashes periodically 🙁
on the frontside of the display ist a
transparent green polarizing film (i think ?)
when removing the backlight, the other filters
are just squeezed in between the backlight
and the back of the display (not glued, etc.).
so do you think that i should put the polarizing
sheets, filters, etc. also onto the ohp, or should
the display itself (with the front polarizer) be
enough ?
i still don't understand, why it flashes periodically 🙁
kolima said:Cyberdemon :
I don't really understand ....
There's a film glued on the front side of the LCD.
On the other side the films can be removed.
Must we keep them ???
Yes.
I can tell you that im 100% sure it has nothing to do w/ the polarization sheets. AND, I can tell you how you can test if its a grounding problem. For grounding, try running it with all the boards attatched to the original chassis. Everything should work even though that one pcb on the LCD is not grounded. If it doesnt work, then I doublt the whole situation is a grounding problem.
well, i hope that it will be a grounding issue (but on kolima's page (great page btw., helped me to renew my french 😉) there is a setup of the same screen without any grounding at all).
I retried it today, opened the case layed the screen on the ohp connected the driver board and power supply, turned it on, and..........
nothing 🙁
screen flashes again every few seconds or so, no real picture appears, rebuilt the screen (removed some dust i inserted accidentally while dismantling the first time while doing so 🙂).
turned it on again (this time fully assembled) and it still works.
this seems to be a hard one to find out 🙁
but now i'll know what to do this weekend 😉
I retried it today, opened the case layed the screen on the ohp connected the driver board and power supply, turned it on, and..........
nothing 🙁
screen flashes again every few seconds or so, no real picture appears, rebuilt the screen (removed some dust i inserted accidentally while dismantling the first time while doing so 🙂).
turned it on again (this time fully assembled) and it still works.
this seems to be a hard one to find out 🙁
but now i'll know what to do this weekend 😉
Cyberdemon said:
Thanks...
My setup is without grounding, but the LCD don't work with my portable computer (no ground).
I must use my tower.
The LCD works, as soon as i connect the VGA connector (the computer is OFF !!!)
Strange ....
it gets even stranger 😉
when i had disassembled my screen, i used my laptop to test it, and it won't work with it (just like yours won't), but when it is halfway assemled it does also display a picture with the notebook (not only the normal pc). this leads me to two things, to test next :
1.) disassemble the whole stuff again (third time for now 🙂 ) and this time don't test it with the notebook, but with a "normal" computer, if it works i'm curious what the difference between my pc and my notebook is (remember, it does work with the notebook, when it's halfway assembled).
2.) if it also won't work with my pc, when it's disassembled and on the ohp i'll have to reassemble it step by step and catch the moment when it displays a picture again. this way i hope to detect the error i can't quite see for now 🙁
@kolima : could you describe how the "not works with notebook" looks ? (i know, this sounds strange 😉 ) for me it is just a black screen, when it's turned on with occasional flashes on the screen (seems like to display is doing it's autosync-thing and won't properly negotiate with the notebook's graphic-card).
damn, i want to watch ghostbusters on a 120" screen, this marshmallow man's gonna be huge 😀
when i had disassembled my screen, i used my laptop to test it, and it won't work with it (just like yours won't), but when it is halfway assemled it does also display a picture with the notebook (not only the normal pc). this leads me to two things, to test next :
1.) disassemble the whole stuff again (third time for now 🙂 ) and this time don't test it with the notebook, but with a "normal" computer, if it works i'm curious what the difference between my pc and my notebook is (remember, it does work with the notebook, when it's halfway assembled).
2.) if it also won't work with my pc, when it's disassembled and on the ohp i'll have to reassemble it step by step and catch the moment when it displays a picture again. this way i hope to detect the error i can't quite see for now 🙁
@kolima : could you describe how the "not works with notebook" looks ? (i know, this sounds strange 😉 ) for me it is just a black screen, when it's turned on with occasional flashes on the screen (seems like to display is doing it's autosync-thing and won't properly negotiate with the notebook's graphic-card).
damn, i want to watch ghostbusters on a 120" screen, this marshmallow man's gonna be huge 😀
thinking about it, it does make sense 🙂
let's say that this flash/blinking stuff is really the display trying to negotiate which the graphic-card (about which refresh refresh rate to use, etc.) and it can only succesfully (interferences ?) do so, when it's properly grounded.
your display only works when connected to the tower --> the graphic card in your pc (grounded by the pc) controller shares it's grounding with the lcd-controller, so both are grounded and you get a picture. when connecting the laptop, the laptop itself has no ground (as far as i know there are only two wires going from the power supply into the laptop), so the laptop's graphic adapter is unable to provide grounding to the screen-controller, so nothing is grounded and they can't negotiate --> no picture.
what made me think is, why it does work with the notebook, when assembled. but when assembling, it reconnected the lcd-screen's ground (to the metal plate, the screen controller resides on). so this time the screen controller is able to share it's ground with the laptop's graphic card --> picture 🙂
i hope that this will solve my problem, can't wait to get home, to try it 😉
let's say that this flash/blinking stuff is really the display trying to negotiate which the graphic-card (about which refresh refresh rate to use, etc.) and it can only succesfully (interferences ?) do so, when it's properly grounded.
your display only works when connected to the tower --> the graphic card in your pc (grounded by the pc) controller shares it's grounding with the lcd-controller, so both are grounded and you get a picture. when connecting the laptop, the laptop itself has no ground (as far as i know there are only two wires going from the power supply into the laptop), so the laptop's graphic adapter is unable to provide grounding to the screen-controller, so nothing is grounded and they can't negotiate --> no picture.
what made me think is, why it does work with the notebook, when assembled. but when assembling, it reconnected the lcd-screen's ground (to the metal plate, the screen controller resides on). so this time the screen controller is able to share it's ground with the laptop's graphic card --> picture 🙂
i hope that this will solve my problem, can't wait to get home, to try it 😉
So the system (Kolimas) works when it's grounded via LCD's and PC's power supplies.
Btw. shouldn't that green wire to be connected somewhere???
Btw. shouldn't that green wire to be connected somewhere???
Im having the same experience with my FP557s. Took it all apart and nothing. Put it back together and it was working. Something needs to be grounded.
i got it 😀
it seems to have really been a grounding issue, it does work with my normal pc 🙂 (even though, it displays an "out of range" error message, but this may be, because i booted the system with another monitor, so maybe it didn't like the refresh rate).
anyone knows, if the screen itself is encased in protective glass from both sides ?
it is obviously on the front side, cause this side is exposed when using the screen, as one is supposed to do 😉
but what about the back side, i got some dust "behind" the screen, and didn't dare to wipe it away, because it thought i might damage the display doing so.
for now it is reassembled (need to build a protective frame and arrange some fans to cool it down, i also need to buy a metal hallide bulb, because i just got the standard ohp bulb). so the dust is still in the assembled display, does it damage the screen in some way, if there is dust on the backside of the screen (i think if there's protective glass it won't).
Thx for your support,
cu,
Cyberdemon 😉
it seems to have really been a grounding issue, it does work with my normal pc 🙂 (even though, it displays an "out of range" error message, but this may be, because i booted the system with another monitor, so maybe it didn't like the refresh rate).
anyone knows, if the screen itself is encased in protective glass from both sides ?
it is obviously on the front side, cause this side is exposed when using the screen, as one is supposed to do 😉
but what about the back side, i got some dust "behind" the screen, and didn't dare to wipe it away, because it thought i might damage the display doing so.
for now it is reassembled (need to build a protective frame and arrange some fans to cool it down, i also need to buy a metal hallide bulb, because i just got the standard ohp bulb). so the dust is still in the assembled display, does it damage the screen in some way, if there is dust on the backside of the screen (i think if there's protective glass it won't).
Thx for your support,
cu,
Cyberdemon 😉
Cyberdemon: there's some protective surface in the back because i wiped both sides to clean. I noticed that a little more link sticks to the backside so its definitly not the same surface as the front. Anyways, yah, I wiped the back and it still works fine.
This might be the grounds that were missing. The third prong from the plug grounds the metal board, so connect these three together. It should work without using the computer as a ground. I have a few more things to make and mount, so I might not be able to try this for a few days.
An externally hosted image should be here but it was not working when we last tested it.
The controller board needs to be grounded with the PCB that is connected to the panel itself. I did it with my disassembled FP557s and now it works well, before just flashed when turned on.
Here's attached picture that shows what I did (Just in case you can't understand my poor english 😀)
Here's attached picture that shows what I did (Just in case you can't understand my poor english 😀)
Attachments
Here's the pic:
An externally hosted image should be here but it was not working when we last tested it.
The panels seem to be a bit different (mine is a 567s). I left the power supply and controller on the metal frame, they originally were and connected the display pcb to the controller with the two flexible cables (these are the only connection between controller and display-pcb). It works 😀
I'm still waiting for my mh-bulb. I tested my setup with the original OHP-bulb and it produced a rather good picture, but ran to hot. I built a protective case for the screen. It is made of 2 picture-frame-glassplates and a windows-isolation-tape, which runs around the borders of each glassplate.
You take the top plate off, put the screen in and put the screen-pcb on the window-isolation tape. Then you put the top glassplate onto it, so no dust gets on the screen (that's what the window-isolation-tape is for).
The glassplates are about 1-2cm seperated from each other. My problem with this setup is now, that the glass-plates seem not to let enough light through, so that my picture got very dark 🙁
I hope, the MH-bulb will fix this issue, cause i would like to keep the protective-glassplates around the display.
btw. does anyone know, if you can buy a longer version of the flexible cables which connect the controller to the display-pcb ?
The problem i'm also facing is, that when i connect the display-pcb to the controller, the power-supply gets a bit in the way
(sits on top of the display-pcb), i saw that kolima and pezku both build a cable to move the power-supply away from the controller to solve this,
I think this will be the easiest way though 🙂
cu,
Cyberdemon
I'm still waiting for my mh-bulb. I tested my setup with the original OHP-bulb and it produced a rather good picture, but ran to hot. I built a protective case for the screen. It is made of 2 picture-frame-glassplates and a windows-isolation-tape, which runs around the borders of each glassplate.
You take the top plate off, put the screen in and put the screen-pcb on the window-isolation tape. Then you put the top glassplate onto it, so no dust gets on the screen (that's what the window-isolation-tape is for).
The glassplates are about 1-2cm seperated from each other. My problem with this setup is now, that the glass-plates seem not to let enough light through, so that my picture got very dark 🙁
I hope, the MH-bulb will fix this issue, cause i would like to keep the protective-glassplates around the display.
btw. does anyone know, if you can buy a longer version of the flexible cables which connect the controller to the display-pcb ?
The problem i'm also facing is, that when i connect the display-pcb to the controller, the power-supply gets a bit in the way
(sits on top of the display-pcb), i saw that kolima and pezku both build a cable to move the power-supply away from the controller to solve this,
I think this will be the easiest way though 🙂
cu,
Cyberdemon
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