openrcforums

It's this guide: http://ok-rimr.com/en/how-to-do-it/turn ... 0815209518
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The transistor was bought from a local supplier and looks the same as the one in the mod.
Could it be because I wrapped the transistor in heat-sink and maybe somehow damaged it with the heat?
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And I made only one cut as in this picture (yellow line): https://picasaweb.google.com/1053552304 ... 4560261554
In the video the cut looks a bit more wide... not sure.. is there any other cut I have to make for this to work?

There are thousands of transistors that look the same as the BS170, but they are different.
What is the reference of the transistor you bought? What are the numbers written on it?
A couple pictures of what you did might also help..

João

Here it is, attached.

All I can say is that you should check all your connections again..

Maybe post a good picture of your little board and the connections to it..
Your problem sounds like the 2 transistor outer legs might be swapped..

João

I have a spare BS170 transistor, but identical and I'm thinking of replacing it..

Your connections look correct.
Assuming you have er9x installed on your radio, and depending on the version of the firmware, if you do to radio setup/Audiohaptic (I think), what do you have selected in "Sound Mode"??

João

er9x r820
v1.96-Mike

Sound Mode: Beeper (and I tried all modes and for some the display dims and won't go full brightness)

Ok, are you really sure, that transistor is actually a BS170 and not an equivalent? I'm asking because some people used the 2N7000 instead. it is basically the same but it has a different pinout.

Something else that it could be happening is the transistor not turning OFF completely because there isn't a resistor between it's Gate and source. Maybe you could solder an 100K resistor between those pins. Please see picture.

João

It says BS170 on the transistor... it should be a BS170 (?)
I'll try to find locally a 2N7000 transistor. I see on the wiki that it's the same with BS170 except it has the outer pins swapped.
How many W for the 100k resistor?
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The fact that it dims rather than switching completely off, isn't that bad... but I'm worried it's something wrong there and could hurt my transmitter.

A small 1/4 watt resistor should be fine.
You don't have to get a 2N7000, the BS170 is fine. I just wanted to point that there were others that had a similar problem because of swapping the pins..
João

I have checked the transistor with a multi-meter and it was damaged. Probably DoA or by heat.
After replacement, the problem is solved. The BL switches off completely.

Thanks for your support!!

Glad is working well done

João