Blown IC

[MTCA]

Hi,

I recently blew up my Boss TU-2 (among others...) and can't find a schematic for it... The IC1 (looks like a transistor) is in two pieces but I don't really know what it is... it's marked S815 , C50a and 3125  . Anyone can help me out with this one..? The power-LED is always on when it's powered with battery or PSU and it's plugged in...

Thanks,
M

[R.G.]

That's interesting. How exactly did you blow it up?

[MTCA]

It blew up after some major voltage fluctuations in a club... it was powered with a 1SPOT. Only my Boss pedals were damaged (TU2 and DS1). I fixed the DS1 by replacing a electrolytic capacitor that had, literally, BLOWN up. I heard them both blow, and smoke came out of all jacks  the adaptor is also broken, but I bought a pedal power

[mth5044]

That sucks to hear, but that must have looked awesome.

[MTCA]

Haha... it did!  when i stomped them afterwards it came puffs of smoke from the three jacks, a cool effect in its self 

But I really hope to be able to fix the TU2, since I managed to with  the DS1...

[R.G.]

It blew up after some major voltage fluctuations in a club... it was powered with a 1SPOT. Only my Boss pedals were damaged (TU2 and DS1). I fixed the DS1 by replacing a electrolytic capacitor that had, literally, BLOWN up. I heard them both blow, and smoke came out of all jacks   the adaptor is also broken, but I bought a pedal power

Wow. That's some interesting fireworks. But I guess there's not much that can be done when the power network goes mad.

I can't find a schemo for it, but I'd guess it's a voltage regulator. Can you get a good picture of the top of the PCB? If I see the parts, I may be able to guess from the others what it may be. It is possible that all the ICs are fried. Tuners are often almost all logic circuits, and they die if they get more than 5V (or less for some of them). But it's worth putting in new parts to try.

[DougH]

She blowed up real good: http://www.funnyordie.com/videos/c3ec14d084/sctv-farm-film-blowup-f-meryl-streep-from-thaffner

[slacker]

I can't find a schemo for it, but I'd guess it's a voltage regulator.

Good guess sir, I just popped mine open and I'm certain it's a 5 volt regulator. 1 leg is grounded, another is connected to the +9  volt terminal of the DC jack through a 1N400X type diode and the third has 5 volts on it with connections from it going all over the place. So I don't see what else it can be.

I guess it can be replaced with a 78L05 except that the pinout is different. Looking at the board from the trace side with the DC jacks at the top the pinout is  Ground, Input, Output.

[MTCA]

Thanks for the replies!!!

The only voltage regulators I have is 7815... I guess thats 15V, and will probably not work, right? I'm kind of new to this... 

[Zben3129]

Yeah no go on the 7815. You want to look for 7805 (which is NOT 7905). Hopefully the regulator blew without slamming the other IC's in the process.

Zach

[MTCA]

Hmm... there isn't any other smart way to try to regulate the voltage?? If not, I have to order parts from germany or so, and maybe it wont work... 

[BlueToad]

You'd probably want a 78L05, in a to-92 pack, a 7805 is typically in a TO-220 and rated for 3-5x more current.

[Zben3129]

I thought the regulator in the TU-2 was a 220 package? Maybe not I just seem to remember that from something

Just use whatever matches 

[German]

Maybe 5.1v Zener would help?

[MTCA]

Maybe 5.1v Zener would help?

Would it?

[Zben3129]

9v - 5.1v = 3.9v

9v - 4v = 5v

I don't think I would use a zener here. Its regulated for a reason I am assuming. Logic chips are picky and damageable.

Zach

[MTCA]

9v - 5.1v = 3.9v

9v - 4v = 5v

I don't think I would use a zener here. Its regulated for a reason I am assuming. Logic chips are picky and damageable.

Zach

Ok, thanks for answering 

I'll try to get my hands on a voltage regulator then...