Hello all,
First time post here. I was wondering if anyone can help me identify a part. I called digi-key and the tech guy said he couldnt find it. There are 3 sot-23 transistors in the rf section of a board im trying to repair. Out of 100 boards half of them are marked with just an "H" and the other half of them they are marked "V Op". I have pulled them off the boards and there are no marking under it either. If anyone can point me in the right direction to figure out what these guys are i would really appreciate it.

Thanks
Chuckb

 

SOT23 can have several footprints (number of pins). Which one is it?

Can you post a photograph?
What board is it, model number, equipment etc?

 

if it has 3 pins it's likely a transistor, MOSFET, or diode.

You can test for diode with multimeter, use a transistor tester, and test if it acts like a MOSFET. Doing a repair without schematic or without to know what's the intended function is not easy.

 

3 pins - pic coming soon

 

i attached a pic .. lets see if it works. i have seen 3 different ones here. the pic has 3 that say "VOt" the other board says "VOp" and another one just has an "H" on all 3 transistors. Its part of an RF circuit so im assuming there gonna be RF transistors.

 

Find the data sheets for the following and look through them for what marks the manufacturer put on them.

HBAT-5400 - Schottky diode
HBAT-540B - Schottky diode
PRF947 - NPN transistor -- possibly what you need.
VN0605T - N channel MOSFET

 

There are a few SMD that starts with "V" and the closest one is

V1p

BFT25

Phi

N

SOT23
npn RF 5V 6.5mA 2.3GHz

Take a look at this web site

http://www.marsport.org.uk/smd/mainframe.htm

Allen

 

Thank you Allen and thank you BSomer,

Bsomer you may be right and that prf947 might be the right one as this board is a philips printed board with mostly philips components on it. So I will order a few of these and try them out.

Allen i also found the v1p and will probably pick some of those up as well there pretty cheap.

thank you so much again for the help!!!