Did i blow my ic chip?

Started by HeavyFog, February 14, 2017, 04:33:22 PM

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HeavyFog

Well i just made a silly mistake. After powering up my tonepad blue box build and having it not working, i noticed i accidentally had the JRC 4558D in backwards. I reversed it and it still didn't work. The only thing i did different from the layout was bypassing the volume pot with a jumper, leaving the spot where the volume ground would go empty. Did i blow the chip by having it in backwards?

EBK

#1
Maybe.  Easiest way to tell is to put a different chip in and see if it comes to life.  Any dual op amp should work.
  • SUPPORTER
Technical difficulties.  Please stand by.

HeavyFog

Don't think i have any others on hand right now or any pedals i could borrow one from.

EBK

Then look at the spec sheet and see what voltages the JRC4558D can handle.  Otherwise, whip up something simple on a breadboard to test your chip.
  • SUPPORTER
Technical difficulties.  Please stand by.

HeavyFog

according to the datasheet 9v (what i used) should be fine. I'm pretty sure its the chip. After prodding it with my finger while plugged into my amp it generated a signal back from the output, about back to the chip when i touched i with my finger. This build i was very careful with parts and orientation so i don't thin anything else is to blame. Still not sure though.

HeavyFog

After looking around i just found out that my 2sc1849 transistors are backwards. Il switch them around and try again. Lets hope this works

HeavyFog

#6
Update #2 just took the transistors out and one of the leads broke off. Looks like il need more. I'm fairly sure the pinout for them is (looking at the round side, left to right) EBC and not CBE, the way i had it wired. I think i found my problem. Il be ordering a new 4558D (and a CD4013 to be safe) along with them and this time il socket the transisitors to be sure i'm getting it right.