Hello, Back with something new. Have a Dell 1901FP monitor with no signs of life. Connected to AC, cycled power button, no LED or anything visible, audible or smellable.
Dis-assembled. Saw no evidence of bulging CapXon capacitors on power supply board or anything anywhere else which looked out of the ordinary. Used ESR meter and found 2 caps suspect. C809 – 22uf 50V read 68 and C824 – 22uF 50V read 17. From past experience and countless suggestions on Badcaps I ordered and replaced all electrolytic on power board with Panasonics, except for the big one. I will list all caps and values, not for my benefit but maybe will be handy to someone someday.
C805 – 50uF 400V big one, did not replace
C101 – 1000uf 25V, C109 – 220uF 25V, C809 – 22uF 50V, C810 – 47uF 50V, C813 – 1000Uf 10V, C814 – 1000uF 10V, C820 – 1000uF 25V, C821 – 1000uF 25V, C822 - 1000uF 25V, C824 - 22uf 50V, C830 – 10uF 16V, C831 – 1000uF 10V, C832 – 1000uF 10V, C839 – 680uF 25V. Again, these are all the electrolytic on the power supply board.
When I received the new caps I measured .23 on the replacements for C809 and C824 which was considerably better from 68 and 17 originally measured. Replaced the caps and took pictures of the boards while they were available.
Then I totally assembled the monitor again, minus the chassis and attempted to power it up. I expected something wonderful but got nothing more than originally stated. So to repeat, now with all connected, cycling power button does absolutely nothing.
With meter got .2 across fuse F801 on Power board so connected AC to power connector again. Measured 163.2 DC across large cap and measured 10 pin connector going to Main board and got nothing on any pin. Board says connector should be:
Pin 1 Blue – 5.1 V, Pin 2 Purple – 5.1 V, Pin 3 Yellow – Gnd, Pin 4 Green – Gnd, Pin 5 Black – BRI Out, Pin 6 Brown – INV ON, Pin 7 Red – Audio ON, Pin 8 Orange – Audio DETECT, Pin 9 Gray – Gnd, Pin 10 White – Gnd. The Gnd Pins are grounded to the ground screws but no voltage present.
Not knowing what else to do, I played around with the ribbon cable coming from the switches and was able to get continuity across Pin 1 & 2 – Gnd and Pin 6 when cycling the power button. So figuring the on/off signal goes through the Main board I traced Pin 6 through and ended up at the big Genesis on Pin 46. So in layman's thinking, I figured the Genesis has to somehow tell the Power Board to let the DC come out to play, but that is the end of my reasoning. I attached the data sheet for the chip, but I don't know what I am looking at.
I think I have a pretty good start, but my knowledge is lacking enough to continue. Would appreciate some guidance.
Dis-assembled. Saw no evidence of bulging CapXon capacitors on power supply board or anything anywhere else which looked out of the ordinary. Used ESR meter and found 2 caps suspect. C809 – 22uf 50V read 68 and C824 – 22uF 50V read 17. From past experience and countless suggestions on Badcaps I ordered and replaced all electrolytic on power board with Panasonics, except for the big one. I will list all caps and values, not for my benefit but maybe will be handy to someone someday.
C805 – 50uF 400V big one, did not replace
C101 – 1000uf 25V, C109 – 220uF 25V, C809 – 22uF 50V, C810 – 47uF 50V, C813 – 1000Uf 10V, C814 – 1000uF 10V, C820 – 1000uF 25V, C821 – 1000uF 25V, C822 - 1000uF 25V, C824 - 22uf 50V, C830 – 10uF 16V, C831 – 1000uF 10V, C832 – 1000uF 10V, C839 – 680uF 25V. Again, these are all the electrolytic on the power supply board.
When I received the new caps I measured .23 on the replacements for C809 and C824 which was considerably better from 68 and 17 originally measured. Replaced the caps and took pictures of the boards while they were available.
Then I totally assembled the monitor again, minus the chassis and attempted to power it up. I expected something wonderful but got nothing more than originally stated. So to repeat, now with all connected, cycling power button does absolutely nothing.
With meter got .2 across fuse F801 on Power board so connected AC to power connector again. Measured 163.2 DC across large cap and measured 10 pin connector going to Main board and got nothing on any pin. Board says connector should be:
Pin 1 Blue – 5.1 V, Pin 2 Purple – 5.1 V, Pin 3 Yellow – Gnd, Pin 4 Green – Gnd, Pin 5 Black – BRI Out, Pin 6 Brown – INV ON, Pin 7 Red – Audio ON, Pin 8 Orange – Audio DETECT, Pin 9 Gray – Gnd, Pin 10 White – Gnd. The Gnd Pins are grounded to the ground screws but no voltage present.
Not knowing what else to do, I played around with the ribbon cable coming from the switches and was able to get continuity across Pin 1 & 2 – Gnd and Pin 6 when cycling the power button. So figuring the on/off signal goes through the Main board I traced Pin 6 through and ended up at the big Genesis on Pin 46. So in layman's thinking, I figured the Genesis has to somehow tell the Power Board to let the DC come out to play, but that is the end of my reasoning. I attached the data sheet for the chip, but I don't know what I am looking at.
I think I have a pretty good start, but my knowledge is lacking enough to continue. Would appreciate some guidance.
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