Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

Hi Chungalin, the tv/monitor model is T22B350ND. Searching for these two transistors
in web I found that (probablly) there type is MMBT5086 (it's a Samsung tr.) I'm going to repalce those two transistors with two BC857B (they have the same pin-out and specifications) to see what will happen. Chungalin, do you have the schematic for this psu?...

Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

Hi, sorry for my late reply but I was out of town all the day. Yes I've checked the resistor (it's a 0.3Ω) and it's ok. Also I have test the startup operation of the IC (I've use a variac and I've read ic datasheet) and is normal. Do you have the schematic so you can tell me the type of these transistors?

Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

Yes, not even standby voltage is present.

Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

Hi, first thx for your respond. These transistors are in the upper right corner at solder side, near the screw hole. The monitor/tv suddenly died. So I open it and when i checked the psu I saw a black spot in the area of PWM IC (STR-W6052S). The IC, the bridge rectifier, a capacitor and the 4A fuse were burn. All the Schottky diodes was ok. After I replace these parts I try the psu but there aren't output voltages. I checked the PWM IC Vcc drop down to 9.6V which means that IC's Bias Assist Function was activated. Then I...

If someone has the schematic for Samsung BN44-00505A(PD23A0Q) psu, could pls tell me the type for QM853 and QM855 smd transistors? They marked as 2P, but when I google it I found 2 types (MMBT5086 and FMMT2222R) which are different type.

Hi, has anyone the schematic for the power supply above. I need it for my SamsungTV/Monitor.

Thx

Re: New Members - please post your introductions here

Hello!
My nane is Nikolas, I'm from Greece and I'm an Electrical Eng. Fond with hardware (Since early 80's with Sinclair spectrum)