I keep frying transistors..

[RandomGlitch]

I've built a pedal based on the famous bazz fuss circuit, and it all works just fine.

However during the build and post-build (there's always improvements to be made!) tinkering many of the 2N3904 transistors I was using stopped working.

How easy is it to make this happen?  What was the likely cause? The theories I have are:

1. Too much heat on soldering (Didn't think I was getting transistor *that* hot, but )
2. Shorted the pins together somehow
3. Collector resistor value too low/high?
4. Input to base resistor too high (from other bazz fuss circuit)
5. Bad luck/karma!

What do you think? I looked at the data sheets for the transistor but was unable to figure out if (3) or (4) were the case.

Thanks!

[CynicalMan]

Could be 1 or 2. Try socketing them. http://www.smallbearelec.com/Detail.bok?no=101

[LucifersTrip]

at a penny each, the price of experimentation is easily worth it...keep blowin' em out!


http://www.taydaelectronics.com/2n3904-npn-general-propose-transistor.html

[RandomGlitch]

Yes, I should try socketing stuff really! I will definitely do that next time.

Wow 1 cent, I wonder what the shipping is to make it worthwhile for me?  I'm paying about 65 Australian cents per transistor here!

We get ripped off!

Anyway, it's not so much the cost, rather I don't want to build something that is unreliable because I'm exceeding the ratings.  What should I be looking at on the specs so I can measure voltages or whatever to check its OK?

[LucifersTrip]

Anyway, it's not so much the cost, rather I don't want to build something that is unreliable because I'm exceeding the ratings. 

if you're building 9v boxes, I don't think you have to worry about exceeding any ratings with transistors. for resistors, choose 1/4 watt+, and the caps should of course, be >9v...most choose 12v+

if the effect if working after you box it, my guess is the best chance of it not working in the future would be a bad solder joint...or of course, accidentally using the wrong power supply

[Paul Marossy]

at a penny each, the price of experimentation is easily worth it...keep blowin' em out!


http://www.taydaelectronics.com/2n3904-npn-general-propose-transistor.html

They must be that price because they want to blow them out and get rid of them because thru hole stuff is practically obsolete now.

[DavenPaget]

at a penny each, the price of experimentation is easily worth it...keep blowin' em out!


http://www.taydaelectronics.com/2n3904-npn-general-propose-transistor.html

They must be that price because they want to blow them out and get rid of them because thru hole stuff is practically obsolete now.

Nah ... BJT's still in mass production and element14's prices are similar .

Anyway , i thought he had been placing transistors into oil and FRYING them ... Must have tasted siliconish .

[Paul Marossy]

Wow, they are cheap! I would think they'd be at least 5 cents each. I guess mfg technology has gotten to where they can make these things for a very low cost.