Just repaired a Norwood 19" F199. This is CompUSA private brand and is identical to Tyris T901DB 19".
Problem: when turned-on, the LCD will display an image only for 3 seconds; green light will stay on, and the image would show with a flashlight. My guess was a fault with some of the backlights.
Opening the LCD is simple: the backshell is fixed to the front bezel by a number of plastic tabs, see pic "tab", and sliding a credit card between the back and bezel does the job to separate backshell from the front bezel. As shown in the "shell" pic, the VESA 75mm plates are just glued to the backshell: not a very good mechanical design ! The LCD panel is Hannstar HSD190ME12 also used in Samsung SyncMaster 913V and Benq Q9T3.
As shown in the "back" pic, the LCD has two main boards [1] a processing board LM1X02N see pic "processing" and [2] a power/inverter UP0401UB12Q07 see pic "power"connecting the the processing board by a 12-pins connector with 12VDC/GND/ON-OFF/BRI. Specs for this UMEC board can be found at .
This board powers 4 CCFLs: CN301/302 and CN303/304; when the LCD is powered up, CN301/302 light up for 3 seconds while CN303/304 fail to light. The Electrolythic caps LTEC are not bulging and seems OK. Inspection of the section of the board relating to CN303/304 shows that [1] capacitor C305 0.33micF 250V is cracked and 'smiling' see pic "C305" [2] both transistors C5706 Q305/Q306 have a weird hole see pic "C5706" [3] transformer UMEC UT35D82 T302 might have overheated. The C5706 are Sanyo's 2SC5706 and I ordered equivalent 2SC5707 marked C5707 from eBay: they come in 4 at $3.99 or bundled with rectifier/caps inside kits called "DELL E172FPB E173FPB HP f1703 f1503 REPAIR PARTS" at $5. NTE equivalent is NTE2668.
I replaced C305 and Q305/Q306, and the LCD works. I believe that the processing board tests the CCFLs, and shuts down if any of the CCFLs is not working
Problem: when turned-on, the LCD will display an image only for 3 seconds; green light will stay on, and the image would show with a flashlight. My guess was a fault with some of the backlights.
Opening the LCD is simple: the backshell is fixed to the front bezel by a number of plastic tabs, see pic "tab", and sliding a credit card between the back and bezel does the job to separate backshell from the front bezel. As shown in the "shell" pic, the VESA 75mm plates are just glued to the backshell: not a very good mechanical design ! The LCD panel is Hannstar HSD190ME12 also used in Samsung SyncMaster 913V and Benq Q9T3.
As shown in the "back" pic, the LCD has two main boards [1] a processing board LM1X02N see pic "processing" and [2] a power/inverter UP0401UB12Q07 see pic "power"connecting the the processing board by a 12-pins connector with 12VDC/GND/ON-OFF/BRI. Specs for this UMEC board can be found at .
This board powers 4 CCFLs: CN301/302 and CN303/304; when the LCD is powered up, CN301/302 light up for 3 seconds while CN303/304 fail to light. The Electrolythic caps LTEC are not bulging and seems OK. Inspection of the section of the board relating to CN303/304 shows that [1] capacitor C305 0.33micF 250V is cracked and 'smiling' see pic "C305" [2] both transistors C5706 Q305/Q306 have a weird hole see pic "C5706" [3] transformer UMEC UT35D82 T302 might have overheated. The C5706 are Sanyo's 2SC5706 and I ordered equivalent 2SC5707 marked C5707 from eBay: they come in 4 at $3.99 or bundled with rectifier/caps inside kits called "DELL E172FPB E173FPB HP f1703 f1503 REPAIR PARTS" at $5. NTE equivalent is NTE2668.
I replaced C305 and Q305/Q306, and the LCD works. I believe that the processing board tests the CCFLs, and shuts down if any of the CCFLs is not working
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