Problems with Hyundai ImageQuest L50A LCD

[Scenic]

bought this thing on eGay... (30€ including shipping)

15" Hyundai ImageQuest L50A LCD made in sep. 2001

the power LED was flashing on and off all the time (sometimes green, sometimes orange)..

i opened up the external PSU and well.. thats what i found in there
(notice the almost black crap between those 16V 1000uF Daewoos)

http://bambooz.pytalhost.net/badcaps...i/daewoo-1.jpg
http://bambooz.pytalhost.net/badcaps...i/daewoo-2.jpg
http://bambooz.pytalhost.net/badcaps...i/daewoo-3.jpg
http://bambooz.pytalhost.net/badcaps...i/daewoo-4.jpg

cleaned the pcb and put some new OSTs in there (i didnt want to waste much money on that thing )

well.. the voltage still drops from 12V to about 8 to 9V as soon as i connect the LCD -.-
and the 5V rail drops to a bit more than 4V.

resulting in the LCD instantly turning off when the backlight should turn on (too much load i guess) and then back on... endless loop...

the only cap i couldn't replace was that "king-size" 400V 68uF Daewoo because i had nothing similar rated here and the next electronics store is about 30minutes by bus

well.. then i remembered that i had an external USB HDD case with a f**ked up controller (recognized as "unknown USB device")..
bingo! 12V 2A and 5V 2A

desoldered the connector of the original psu pcb and soldered the cables to the USB HDD case psu...
LCD turns on... "No Signal"
ugly solution (cable mess) but it works

but hey... i was way too optimistic.. i connected my old Pentium 100 Laptop (really handy for testing as the battery still lasts 2 hours ^^) with a test-picture in fullscreen..

whoa.. everything messed up
http://bambooz.pytalhost.net/badcaps/hyundai/001.jpg
http://bambooz.pytalhost.net/badcaps/hyundai/002.jpg
http://bambooz.pytalhost.net/badcaps/hyundai/003.jpg

and within windows.. (not on that P100 laptop )

http://bambooz.pytalhost.net/badcaps/hyundai/004.jpg
http://bambooz.pytalhost.net/badcaps/hyundai/005.jpg

looks like some kind interference.. mostly horizontal..

hmmm.. but why the hell does the OSD show up without this interference!? o.O

http://bambooz.pytalhost.net/badcaps/hyundai/OSD.jpg

really weird... and the Auto-config doesn't help..

any suggestions for the PSU (what to search for or what to check because the voltage still drops with new caps) or the interference on the LCD...?

[Scenic]

Re: Problems with Hyundai ImageQuest L50A LCD

hmmm.. strange...

i wanted to turn the LCD on today with the USB HDD PSU.. and i got the same problems as with the original psu before i recapped it.. turning on and off all the time in an endless loop -.-

but after it got warm it turned on without problems o.O wtf

looked for bad solderpoints and the caps (inside the LCD) and resoldered some that seemed to be a bit weak..
and it has polymer caps everywhere (!).. so that shouldn't be the problem.. (i guess)

and for this distortion... when i set the screen refresh rate to the maximum the monitor supports officially (85Hz) it works almost fine (slight distortion still, but you won't notice it if you don't know it)...

but the lower i set the refresh rate the more distortion appears o.O

and the OSD always shows up without this fuzzing interference/distortion... so i guess the problem is somewhere in the analog input area... but where..!?

this thing kinda drives me mad

[willawake]

Re: Problems with Hyundai ImageQuest L50A LCD

doubt they are polymers. just lytics without sleeve which are too small to require vents.

[Scenic]

Re: Problems with Hyundai ImageQuest L50A LCD

hmm... now i put this thing back together i cant take pics ..

but i bet i have to open it up again very soon (forgot to connect 1 backlight CCFL )

[Fizzycapola]

Re: Problems with Hyundai ImageQuest L50A LCD

doubt they are polymers. just lytics without sleeve which are too small to require vents.

Too true.



These cost 1p each retail price!
Solid cost 100p each.

Great if you want people to think you've used solid polymers.

Bought some for myself yesterday for 0.5p each to make my soundcard "look" the sh*t! as it were. Most people won't know the difference.

[Scenic]

Re: Problems with Hyundai ImageQuest L50A LCD

all caps inside seem to be fujitsu polymers (red marking/writing) like in this pic


some caps (3 or 4 of them) are yellow ones with a T vent and marked with an |F| so they seem to be fujitsus too..

it does look a bit weird inside that LCD.. because the metal plate that covers up the PCB is full of holes where the caps are
just like a swiss cheese ..

[Scenic]

Re: Problems with Hyundai ImageQuest L50A LCD

crap.. too late to edit -.-

edit: all of them are through-hole caps..

and here's a pic of those yellow polys (or hybrid polys/lytics because of the T vent!?)


i bet this LCD was extremely expensive back then..
but they also extremely cut the costs down with that el-cheapo PSU they shipped with it (daewoo caps, poor layout, barely enough solder to hold everything on the PCB, etc. ...)

and i've never seen a LCD with just a 5V and a 12V input (both only 2A)

i almost forgot..
1 single cap is (was) a unknown brand ("NCK" !?! never heard of that before) 25V 1000µ lytic at the 12V input.
i replaced it with a 1200µ 16V nichicon (laying parallel to the PCB because its physically too big (too high and the diameter doesnt fit into the hole in the metal plate that covers the PCB))


and BTW: good night
its 4:30 AM here right now