Good evening guys,
Here I have a W2242PKT display which started to have the nasty 2-seconds-to-death issue back a few weeks ago.
Thing is, after a few turn-on-turn-off cycles the monitor would stay on until I turned the PC off - so this is how I fared the last weeks.
Anyways, this grew quite annoying so I thought I might aswell fix it.
As is said, 2-sec-to-black. If I turn the monitor off and on sometimes it will stay on until I cut the power (reboots are fine). Since last week the monitor would flicker but stay on if I try long enough. Also it emits high-pitched noise while flickering or if I set the brightness low.
Speaking of which, trying to set the brightness right after the monitor gets out of the black-screen-loop does nothing. Brightness=0 is the same as Brightness=100 - preceived brightness is 100.
I went out to measure the T301 transformer (since it is directly at the CCFLs), but I have trouble to interpret the readings from my VC130 voltmeter (set to 2kOhm):
Measuring Pin 1 to Pins 2-6 gives me a 001, basically a resistance too low to measure
(going down to 200 Ohm gives me 00.3 which is the min resistance the bloody thing can measure)
Same results if I measure pins 2, 3, 4, 5 and 6
Measuring any pin to pins 7 or 10 gives me 0L, so no connection
The only proper reading I get is between pin 7(EL21) and 10(EL22): 422 Ohm
With a continuity test I get 422 between 7 and 10 (no beep) and 0+beep between 1 and 6.
Measuring T101 I get no proper reading at all:
Pins 7(EL20) and 12(EL19) show 001 to 8,9,10,11,12 and 0L to 1(EL16),2,4(EL17),6(EL18)
Pin 1 shows 001 only to 2; pin 4 only to Pin 6
It looks like I am measuring rubbish >.>
So folks, this is where I need your help.
Where exactly are the primary and secondary windings here?
Do the symptoms indicate a bad transformer at all? Or is it a capacitor?
Display Markings http://imgur.com/ZlwPo3u http://imgur.com/5ONXLe7
Inverter Board Front http://imgur.com/VkkEGtx Back http://imgur.com/VU2nqj2
T101 http://imgur.com/3EP1uCE T301 http://imgur.com/rZUn44z
Logic Board Front http://imgur.com/P8GnM4I Back http://imgur.com/t6KN1EM
Cheers,
UPDATE:
Plugged in the monitor while disassembled, to test the CCFLs acording to the guide.
Plugged in only the lower one, black after 2sec, as expected.
Plugged in both and the monitor came online instantly, without 2sec-to-black.
But I was able to make an observation: buzzing sound in the upper left corner (if viewed from the front) - basically in the area where the ribbon cable is connected.
No such thing in the other corners.
Normal behaviour? Or is it an indicator for a dying CCFL since the lower one does not emit such sound?
UPDATE2: the buzzing can be heard across all the upper edge, not only in one corner.
UPDATE3: the longer I look into it, the weirder: as long as the monitor lies flat, face-down on the table, it works. As soon as I lift it, 2sec2black. A short somewhere?
Here I have a W2242PKT display which started to have the nasty 2-seconds-to-death issue back a few weeks ago.
Thing is, after a few turn-on-turn-off cycles the monitor would stay on until I turned the PC off - so this is how I fared the last weeks.
Anyways, this grew quite annoying so I thought I might aswell fix it.
As is said, 2-sec-to-black. If I turn the monitor off and on sometimes it will stay on until I cut the power (reboots are fine). Since last week the monitor would flicker but stay on if I try long enough. Also it emits high-pitched noise while flickering or if I set the brightness low.
Speaking of which, trying to set the brightness right after the monitor gets out of the black-screen-loop does nothing. Brightness=0 is the same as Brightness=100 - preceived brightness is 100.
I went out to measure the T301 transformer (since it is directly at the CCFLs), but I have trouble to interpret the readings from my VC130 voltmeter (set to 2kOhm):
Measuring Pin 1 to Pins 2-6 gives me a 001, basically a resistance too low to measure
(going down to 200 Ohm gives me 00.3 which is the min resistance the bloody thing can measure)
Same results if I measure pins 2, 3, 4, 5 and 6
Measuring any pin to pins 7 or 10 gives me 0L, so no connection
The only proper reading I get is between pin 7(EL21) and 10(EL22): 422 Ohm
With a continuity test I get 422 between 7 and 10 (no beep) and 0+beep between 1 and 6.
Measuring T101 I get no proper reading at all:
Pins 7(EL20) and 12(EL19) show 001 to 8,9,10,11,12 and 0L to 1(EL16),2,4(EL17),6(EL18)
Pin 1 shows 001 only to 2; pin 4 only to Pin 6
It looks like I am measuring rubbish >.>
So folks, this is where I need your help.
Where exactly are the primary and secondary windings here?
Do the symptoms indicate a bad transformer at all? Or is it a capacitor?
Display Markings http://imgur.com/ZlwPo3u http://imgur.com/5ONXLe7
Inverter Board Front http://imgur.com/VkkEGtx Back http://imgur.com/VU2nqj2
T101 http://imgur.com/3EP1uCE T301 http://imgur.com/rZUn44z
Logic Board Front http://imgur.com/P8GnM4I Back http://imgur.com/t6KN1EM
Cheers,
UPDATE:
Plugged in the monitor while disassembled, to test the CCFLs acording to the guide.
Plugged in only the lower one, black after 2sec, as expected.
Plugged in both and the monitor came online instantly, without 2sec-to-black.
But I was able to make an observation: buzzing sound in the upper left corner (if viewed from the front) - basically in the area where the ribbon cable is connected.
No such thing in the other corners.
Normal behaviour? Or is it an indicator for a dying CCFL since the lower one does not emit such sound?
UPDATE2: the buzzing can be heard across all the upper edge, not only in one corner.
UPDATE3: the longer I look into it, the weirder: as long as the monitor lies flat, face-down on the table, it works. As soon as I lift it, 2sec2black. A short somewhere?