Obviously this question is a little open ended, but I'm not sure where else to turn to fix my problem. Basically, a project I'm working on has a 5609 transistor and the emitter pin snapped. After some research I wasn't able to find a replacement on a website that I trust. I have a few pn2222 transistors and I was wondering if they might do the job. The pinout is the same and they're both npn transistors so my basic knowledge is telling me it could work, but basic is the keyword here. Does anyone have any insight on this? If more information is needed let me know!enter image description hereenter image description hereenter image description here

  • \$\begingroup\$ Compare the specifications. \$\endgroup\$
    – Hearth
    Apr 8, 2021 at 21:09
  • \$\begingroup\$ I was looking through both data sheets and the pn2222 seems to have higher max voltages across the board, but for current it says 600ma as opposed to the old one which says 1A. So I'm assuming that would be an issue if the power is running more than 600ma? \$\endgroup\$ Apr 8, 2021 at 21:16
  • \$\begingroup\$ Yes. You'll have to look into how the circuit works to determine a suitable replacement. I've never seen a 5609 before, so it may have some particularly uncommon specifications--else they would likely have used a common transistor. \$\endgroup\$
    – Hearth
    Apr 8, 2021 at 21:22
  • \$\begingroup\$ Yes it would. Where is it being used and how. \$\endgroup\$
    – Passerby
    Apr 8, 2021 at 21:23
  • \$\begingroup\$ Yea it seems like the answer is going to be no here. And it's being used in an nes clone console that I'm (trying to) turn into a handheld device. The transistor is collecting straight from the dc power connector so I'm assuming it's the main transistor for the board. I'm actually bypassing it for the battery connection, but I have the power connections set up to a switch so I can use either the battery or the wall plug to power it, which is where the break comes in, because I cut the emitter pin and soldered a wire straight to it and after flipping the board a few times it snapped \$\endgroup\$ Apr 8, 2021 at 21:38

1 Answer 1


Replacing one transistor with another depends on the application and the specs. If its working as a simple power switch for some leds, its easier than if its being used as a signal amplifier in a sensitive radio component or a voltage follower setup.

If its a simple power switch then look for the hfe or gain, the base emitter forward voltage drop, the max voltage and currents involved. You may need to adjust a base resistor or deal with differences in heat management.

  • \$\begingroup\$ Excuse my poor terminology and choice of words, since my electrical knowledge is self taught. That being said, what I'm working on is turning a clone of the nes game console into a handheld device, so the transistor is the main power transistor of the console. Its a very shoddy circuit board with obviously old or off brand parts so I was hoping that the pn2222 was a better fit than trying to find the same one. But it's already looking like the pn2222 won't work since the current rating is nearly half of the previous transistor \$\endgroup\$ Apr 8, 2021 at 21:29
  • \$\begingroup\$ Only if its using over 600 mA. You say its coming from the DC input, the positive going straight to the collector? Then its not a normal setup as most NPN power usage is as a low side switch (emitter connected to ground). Can you take pictures and figure out a schematic? What is the model of the NES clone? Maybe it's being used to control a regulator or something. \$\endgroup\$
    – Passerby
    Apr 8, 2021 at 21:47
  • \$\begingroup\$ I just added pictures of the top and bottom of the board. The 3 holes on the left side are for the transistor which I already removed. If you're looking at the bottom of the board (green) the pins are base collector emitter from top to bottom. Hopefully this is helpful bc I'm not too sure what other info I could add that would be useful \$\endgroup\$ Apr 8, 2021 at 22:16
  • \$\begingroup\$ @WalterWhite Seconding passerby, a schematic would help a lot. Please do buzz one out. \$\endgroup\$
    – Hearth
    Apr 8, 2021 at 22:17
  • \$\begingroup\$ I will take a SWAG and say it may be connected as a series pass transistor part of the boards linear power supply. \$\endgroup\$
    – Gil
    Apr 8, 2021 at 23:30

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