My second failed attempt at a CORE

[jrkirkish]

Alright, I've built my second core, and now this one doesn't work. I'm just going to go through the MIDI troubleshooting guide and tell you guys my results for each test. At the bottom are pics of my core.

First off, I'll describe my current situation.

I put a SMASH CORE module together, and power it up.  The LCD displays the top row of solid blocks for a second or so, and then goes blank. I am not trasmitting any MIDI. I even tried the LED in the MIDI out port trick. I am at an impasse.

Now, for the diagnosis:

Measuring the Vdd at the points listed in the CORE midi troubleshooting guide leaves me with 7.6-something volts. Not five.

Measuring ground as per the same guide leaves me with 13-something volts. That's really high.

I checked all the pins as stated in the CORE building guide before installing the ICs.

Well, that's it except for a Quick question: My pic, from SmashTV is already burned with MIOS, right? I don't have to upload MIOS, right?

[stryd_one]

I see a lot of splashes and stuff all over that board man... Check for shorts maybe.... The parts also look very 'wonky'... I think overall you need to take more care when you solder. No offence :) A pretty board is usually a good one.

Yep, smash's PICs have MIOS on them.

OK so your Vdd is 7.6 and your ground is 13, what are you putting into it? What is it right after the rectifier? Does the vreg get hot?

Edit: I can see something (solder?) hanging off the top 5th pin from the left of the PIC on that bottom picture... and the 6th... and the 9th... Joints 3rd and 5th from the left on the bottom are dry....Looks like a short between the pins of the bypass cap (left side, bottom img, in the middle)....

Maybe it's all artifacts from the camera...

[DavidBanner]

there also a lot of iffy looking solder points, you want to cover the hole completely, not leaving any holes.

take it nice and slow and do it right; the more possible areas of failure the harder it will be to track down any problems. Plus your core is more likely to fail over time if the soldering isn't up to scratch.

[Tanstaafl]

I'll chime in on this one too. 

How do you get to Carnegie Hall?  Practice, Practice, Practice.

I've been soldering for about 40 years, I'm sure I've killed quite a few brain cells sniffing flux.

Just make sure you have the correct Wattage soldering iron for the circuit board you are soldering (with the kinds of stuff we are working with, use an iron that is less than about 20 Watts).  Make sure the board is CLEAN, in our case, Smash makes really good boards.  Touch the tip of the iron to the thing you want to solder, touch the solder to a bit of the pad you are soldering.... thermal conduction, capillary action and gravity will take care of everything else.

Good luck,

gb

[lylehaze]

I don't understand.. Not the first time that has happened.

Normally, all voltages are measured from "Ground".

So how can you possibly have 13 volts from Ground to Ground?

Please set your meter to read DC volts, 20 volt scale.

Connect the black lead to the metal tab of the 7805 voltage regulator.

Carefully touch the red lead to the first and last pins of the 7805, tell us what each of those are reading.

These clues will give us a starting place.

Have Fun,

LyleHaze