Display Dim In HP L1955 19″ LCD Monitor
The complaint for this HP L1955 model HSTND-2B01 19″ LCD Monitor was dim display. After opened up the cover i saw some burnt mark at the inverter board. Further checking found 3 of the 4 C5707 push pull transistors shorted and front side puntured with a hole! No only that, both the p-channel FET D10PF06 also shorted and have some burnt mark in it too. The inverter fuse already open circuited!
Since i do not have the original of the D10PF06 I used an equivalent part number to test it out. I switched “On” the display and it shutdown after 1 to 2 seconds! I thought it could be the backlight problem didn’t realized that it was the substitution part number that gave problem. I used a 15″ LCD Monitor to test out the 19″ backlights (4 backlights) and proven all of the backights were working fine.
The stock that i have FQU11P06 already used up and can’t test the set. I ordered it yesterday and got it today. I took out the replacement number and put in the FQU11P06 PCHANNEL FET, the set came back to life! I have tested it for a while and was not hot to touch. I will run the full test again under Windows high resolution-hope everything is okay.
Conclusion-a wrong replacement of the p-channel FET may lead you think that it was the backlights or inverter IC fault. If possible get the original part number.