Having problems with your HP Pavilion F1903 19" Flat Panel LCD Monitor ?

Testing C5707 Transistors on Benq Inverter Board

\015 Hello everyone,\015\012\015\012\015\012I have a faulty HP 1940 with a Benq\015\01248.LIG02.A01 inverter board. It has the fault where it the screen\015\012goes black after a few seconds, after putting a flash light to it I\015\012could see that the image was still there. i Opened it up and\015\012inspected the inverter board I could not see any faulty caps and the\015\012soldering looks good to me (I'm a novice) so after reading through\015\012the posts here I decided to pull the four C5707 transistors off the\015\012board and test them with my DMM, as I have read here that these\015\012transistors are a common fault with this board. Because I have\015\012little experience testing transistors I was hoping for some\015\012conformation from the experts (you)\015\012\015\012\015\012\015\012I pulled 4 transistors off the board\015\012and kept them separated in pairs as I'm told the fail in pairs.\015\012\015\012\015\012The first pair gave me the following\015\012results (all tested with the diode function on my DMM)\015\012\015\012\015\012Transistor 1 (first pair)\015\012\015\012\015\012B-E .575 v\015\012B-C .575v\015\012C-E Open\015\012E-C Open\015\012\015\012\015\012Transistor 2 (first pair)\015\012Same as above\015\012\015\012\015\012Transistor 3 (second pair)\015\012B-E 0.00v (it did not read 0L )\015\012B-C .349v\015\012C-E .349v\015\012E-C .360v\015\012\015\012\015\012Transistor 4 (second pair)\015\012B-E 0.00v (it did not read 0L )\015\012B-C .444v\015\012C-E .478v\015\012E-C OPEN\015\012\015\012\015\012it seems to me that the second pair is\015\012faulty I was wondering if anyone can confirm this? I have found a\015\012place on ebay where I can order some new C5707s. Also As a precaution\015\012I have touched up the soldering on all the transformers in case this\015\012was the cause of the fault. Anything else I should check?\015\012\015\012\015\012Thanks heaps for all the great tips I\015\012found here I would never have tried this without the advice I have\015\012found on this site.\015\012\015\012\015\012Mike\015

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Repair Help & Product Troubleshooting for HP Pavilion F1903 19" Flat Panel LCD Monitor

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Testing C5707 Transistors on Benq Inverter Board

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Problem for BenQ FP767 Power light does come on, image is there if a light is shined on the screen, i have swapped the 4 2sc5707 transistors as suggested in other posts. Still the same problem, further testing shows no power in the entire area around the transistors (tested across the majority of surrounding connections). Could there be a further problem and is it possible to obtain a board diagram so i can try and track the point of power loss?

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