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Projects => General Questions => Topic started by: matmosphere on February 05, 2016, 02:26:40 AM

Title: Plugged in power before plugging in the ic what did I break
Post by: matmosphere on February 05, 2016, 02:26:40 AM
I'm trying to trouble shoot a Timmy build. I plugged everything in and.. nothing. I quickly realized I had not put the ic in the socket. I corrected it but still nothing. Did I mess something up by doing this. I feel like without the IC current shouldn't be flowing, except through the power filtering section. but I haven't been able to find any other issues.
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: kgull on February 05, 2016, 02:45:15 AM
Nothing bad should happen by forgetting an IC, should just not get any sound. Only thing I can think off hand would be that some capacitors built up enough of a charge and the IC got enough of a shock to fry it when you plugged it in :-\ Make sure you don't have a dead chip then start posting voltages :P
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: gtr2 on February 05, 2016, 11:48:13 AM
Check your voltages and use an audio probe.

Josh
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: matmosphere on February 05, 2016, 09:29:48 PM
Couldn't find a list of voltages, does anybody have them handy?

I have a tl072 in it right now, because I was trying out a few chips to make sure that wasn't the problem. This is what I measured

1 9.21
2 5.07
3 5.07
4 5.02
5 0
6 4.64
7 5.07
8 5.07

Any thoughts?

Title: Re: Plugged in power before plugging in the ic what did I break
Post by: HamSandwich on February 05, 2016, 09:34:55 PM
either you labeled the pins backwards, or your IC is in backwards.
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: matmosphere on February 05, 2016, 09:43:40 PM
Quote from: HamSandwich on February 05, 2016, 09:34:55 PM
either you labeled the pins backwards, or your IC is in backwards.

Oops, I labeled them backwards. Good catch thanks. I should have written down the pins with the readings.. FAIL

Lets try this again

1 - 5.17
2 - 5.07
3 - 4.64
4 - 0
5 - 5.02
6 - 5.07
7 - 5.07
8 - 9.21
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: HamSandwich on February 05, 2016, 10:05:04 PM
Without a link to a schematic, or even the layout you used, can't say for sure, but they are typical voltages for a TL072. Likely a wiring problem, but without pictures, or a schematic or layout, hard to tell. Audio probe is a good way to continue your trouble shooting.
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: matmosphere on February 05, 2016, 10:07:49 PM
I'll snap some pictures later. Thanks
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: jimilee on February 05, 2016, 10:39:15 PM
In the meantime, check your values and reflow everything. You'd be amazed how many times that fixes things. After over 3 or 4 years of building, I had to do that 2 days ago. Makes me feel silly every time I do it.
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: gtr2 on February 05, 2016, 11:19:28 PM
Voltages look good.  An audio probe is your best friend :)
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: matmosphere on February 06, 2016, 12:29:43 AM
Got it, thanks guys. The problem was actually a bad solder joint in my crappy testing rig.  :P
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: matmosphere on February 06, 2016, 12:55:44 AM
I'm glad I thought to check the testing rig. I could have been troubleshooting thec Timmy for days.
Title: Re: Plugged in power before plugging in the ic what did I break
Post by: jimilee on February 06, 2016, 04:25:31 PM
Quote from: Matmosphere on February 06, 2016, 12:29:43 AM
Got it, thanks guys. The problem was actually a bad solder joint in my crappy testing rig.  :P
That's a new one, I haven't seen that one yet.