Fujicom LCD Monitor Repair/Model W2209B
A customer brought this LCD computer monitor to my shop and the problem was a dead monitor. The standby power led did not come on either. The repair with the help of some important tools was easily done.
I opened the back cover and as usual, I scanned the board with my naked eye but could not see any bad components. The two boards in there were so clean which made the repair so easy and so much fun.
At this point, I decided to start the voltage test to see why this monitor was not working. I plugged the power in and tested the voltage at the main capacitor of the power supply and I got 300 volts there which indicated an ok primary power supply. I moved on to the diodes in the secondary section of the power supply and to my surprise, there was some power there but not steady. At first, I thought maybe the problem is the diodes under load are acting strange but when checking them, they tested ok. I tested all the capacitors in the secondary section of the power supply with the blue ESR meter and they all checked fine.
This got me thinking, if the main capacitor is getting the right amount of power and the power is getting out but not steady, that means there is something in between that is causing the power to act in strange way. I was thinking of the SMPS transformer. I know these transformers do not go bad that often but it was worth the checking. I used the blue ring tester to investigate the problem and when placing the meter on the primary side of it, I got no light bars what so ever. Usually when getting no light bars there, I think of the main capacitor or the secondary diodes that is causing this but I already checked them out and they were ok. My problem was the SMPS transformer.
I decided to solder it off board and do further testing. The moment I soldered it out, I saw that one of the legs of the transformer was broken and the wire attached to the leg was loose. I glued the leg back to the transformer and soldered the wire back to that leg, the power was restored and the LCD came to life.
This article was prepared for you by Waleed Rishmawi, one of our ‘Master Authors’ and currently working in the Bethlehem area of Palestine repairing electrical and electronic equipment.
Note: If you have any interesting repair article that you want to share to others please do contact me