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Help with soldering transistor 7805 correcty

Recordable2000

Aug 13, 2023
9
Joined
Aug 13, 2023
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Hello, I'm looking for help to solder in transistor 7805 into an nes clone video game console. This transistor serves as a voltage regulator. Currently in the console is a 8050 transistor, but it's faulty. To solder in the 7805 I need to remove the 8050, a diode and a resistor on the board.
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My question
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Which way should I solder in the 7805? There is a block outlined on one of the solder spots where the transistor is supposed to go. What does that represent? Is that the input, or the output pin? Sorry for my english, I'm not a native speaker. Thank you in advance
 

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73's de Edd

Aug 21, 2015
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Sir Recordable2000 . . . .
One, real l l l l l l l l l l l l l y -real l l l l l l l l l l l l l y-real l l l l l l l l l l l l l y needs to see the foil side of that board.
It is apparent that the board was designed to optionally use EITHER a 8050 transistor and associated Zener diode or a HEFTY full sized (see the printed rectangle board pattern) 7805, if on upwards to an amp of current is needed.
Look to the rear E-caps and expect one to be filtering the incoming full DC supply and the other to be filtering the regulated +5 v supply.
Check their voltages ! . . . . .to confirm.
Also . . . Do take note of the hole that was punched into the chassis just above the 8050 . . . . . I'll just bet that was done to open a foil trace that
was used to connect in, if a 7805 was fitted onto the board, to be used instead of the EL CHEAPO . . .bucolic . . . 8050's capabilities . . .that is now in circuit.
Use the mini schematics to see if your present 8050 is regulating out at its emitter.
Thaaaaaaaaaaaasssssit . . . . . .

1717780255852.png


73's de Edd . . . . .

1717780618847.png
 

Recordable2000

Aug 13, 2023
9
Joined
Aug 13, 2023
Messages
9
Oopsies I made a boo boo.
The block outline indicates pin 1 of the 7805
View attachment 63884
Thanks, nice simple answer. I soldered it like that and now it works great! Thank you very much!
Also, you asked in a previus message how I know the 8050 was faulty. Well, I couldn't run the device on it's recommended 9V because the video would get fuzzy and the transistor would be very hot. Also the 8050 was physically damaged when I took a closer look at it.
 
Last edited:

Recordable2000

Aug 13, 2023
9
Joined
Aug 13, 2023
Messages
9
Sir Recordable2000 . . . .
One, real l l l l l l l l l l l l l y -real l l l l l l l l l l l l l y-real l l l l l l l l l l l l l y needs to see the foil side of that board.
It is apparent that the board was designed to optionally use EITHER a 8050 transistor and associated Zener diode or a HEFTY full sized (see the printed rectangle board pattern) 7805, if on upwards to an amp of current is needed.
Look to the rear E-caps and expect one to be filtering the incoming full DC supply and the other to be filtering the regulated +5 v supply.
Check their voltages ! . . . . .to confirm.
Also . . . Do take note of the hole that was punched into the chassis just above the 8050 . . . . . I'll just bet that was done to open a foil trace that
was used to connect in, if a 7805 was fitted onto the board, to be used instead of the EL CHEAPO . . .bucolic . . . 8050's capabilities . . .that is now in circuit.
Use the mini schematics to see if your present 8050 is regulating out at its emitter.
Thaaaaaaaaaaaasssssit . . . . . .

View attachment 63885


73's de Edd . . . . .

View attachment 63886
Thanks for the info! About the punched hole above the 8050, that's just a screwhole to mount it in the case. I removed the 8050, zener diode and a resistor from the board, then added the 7805 in the place it belongs and now it works perfectly!
 

Delta Prime

Jul 29, 2020
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Jul 29, 2020
Messages
2,204
Also, you asked in a previus message how I know the 8050 was faulty. Well, I couldn't run the device on it's recommended 9V because the video would get fuzzy and the transistor would be very hot. Also the 8050 was physically damaged when I took a closer look at it.
That was my boo boo.
Anyway. you're hired!!! Congratulations! when can you start! There is a sizable sign on bonus... :p
 
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