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Hi fbone.
Do you see the vertical bars when in composite mode ?
I have a samsung 15khz crt that shows this exact vertical bars but only when rgb is enabled, composite and osd menu are clean.
I already tried that and it does change the G2 a bit, +- 10V.
I think it's either the flyback or something on the board that's messed up.
When i press the front menu buttons it has an effect on the clicking.
Maybe an IC chip is messed up ... i don't know.
I paid 10€ for this monitor so it's not...
R912 and L911 are ok.
I checked the caps all seem ok.
G2 wire disconected from the neckboard shows 22V, so it's not related to the neckboard i think.
Regards,
Rade
R412 = 11V
R413 = 88V - 92V (fluctuating).
G2 at neckboard is 22V.
Also heatsink where Q419 is placed and Q419 itself get very hot after like 15-20 seconds. It's untouchable.
The HOT is also getting very hot after a very short time. I don't know if this is normal ?
Regards,
Rade
No worries.
So i placed the HOT properly.
Now it's clicking.
Voltage at rails without touching the VR801:
-D817 Cathode = 82V
-D813 Cathode = 54 - 56V
-D814 Cathode = 11.2V
-Q813 Collector = 11.2V
-Q811 Collector = 06.2V
-D810 Anode = -11.6V.
I guess these are good readings ?
VR801 adjust...
Did that and there was no change at all at both directions,
i switched it till the end with no effect. The voltage remained the same 65.8V at D817 Cathode.
Also, why when i tested the bulb method with the HOT properly connected, the voltage at D817's cathode was between 72.4V - 74.9V ?
and...
L803 connected.
D402 connected.
HOT's base and emitter connected to board, collector is lifted not connected to the board.
Bulb is lit.
No clicking.
-D817 Cathode = 65.8V
-D813 Cathode = 50.2V
-D814 Cathode = 09.7V
-Q813 Collector = 09.7V
-Q811 Collector = 05.2V
-D810 Anode = -09.9V.
Regards,
Rade
I already did this test using multimeter but now i did it again, this is what i did :
HOT
-I disoldered the HOT from the board.
Multimeter at Diode mode:
-Base to emitter = 354
-Base to collector = 330
-Emitter to base = 1
-Collector to base = 1
-Emitter to collector = 1
-Collector to...
This is what i did :
-I reconnected L803.
-Placed a wire between base and emiter of HOT like this :
-Clicking stoped and there is no image.
-Reconnected the bulb :
-There is no clicking.
-Measured voltage at D817's cathode was 65.6V.
-Bulb is lit and not blinking.
You have already suggested...
So i did the test with a 240V 75W halogen bulb.
These is what i did :
The result was :
-First the bulb was lit and then it started clicking.
-The bulb was blinking rapidly (at the rate of the clicking i think).
-Voltage at D817's cathode was between 72.4V - 74.9V (Fluctuating).
What's...
Did that, and same thing happens.
G2 still at 20v - 25v which is too low.
From what i can hear the clicking is coming from the flyback.
Anyways now i dont't even see a proper image only whitish screen. I probably messed up something else inside while i was trying to troubleshoot.
Maybe it's...
I checked for sparks in a completely dark place with the monitor not emitting any light (G2 wire disconnected from the neck) and I didn't see any.
Regards,
Rade
Hello,
So i checked if the x-ray protection was kicking in and it isn't.
What i did next was to measure the G2 voltage.
I desoldered the G2 wire going to the neckboard and discovered that the voltage was too low around 20v-25v dc.
So now i'm realy suspecting a bad flyback.
That would explain...
Thank you for all your help.
I was looking for an identifier on the board and found that it's " C1770NSL".
There are other brands that used this same board on their monitors and i think i found the shcematics for it.
There is another person who had this same problem on his monitor but found no...
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