Using this method, the components should never see more than millivolts. The short guarantees this.

 

Using this method, the components should never see more than millivolts. The short guarantees this.

No doubt that would work quite well - on the few occasions its connected to the bit that's shorted.................

 

Well, the FLIR method is a near instant locator of heat generating issues such as a short. If the OP has access to one, it is a superior method of locating heat generating internal board faults, component faults, heatsink bonding faults, current overload faults, or even shorted faults hidden beneath multi pin components due to solder balls etc. Poking about fine pitch parts for faults can be very tedious.

I had a fault once that wasn't a dead short.....incomplete solder paste remelt bridging UNDER a 0805 part loading the LM317 regulator into thermal shutdown. So the resistance was a few ohms. The FLIR method identified the problem w/o having to de-solder anything to check.
It showed the traces leading to the 0805 part a few degrees warmer than others.

Yes a FLIR camera is a great tool.. Assuming you have the $4000 camera at your disposal..

This guy has all the board space in the world and can't even use the proper spacing for component mounting.
He clearly isn't a professional at this so I HIGHLY doubt he has a FLIR around..

 

Yes a FLIR camera is a great tool.. Assuming you have the $4000 camera at your disposal..

This guy has all the board space in the world and can't even use the proper spacing for component mounting.
He clearly isn't a professional at this so I HIGHLY doubt he has a FLIR around..

We frequently see; "all the gear...........no idea" on this forum.

 

Smaller FLIRs are around $400 these days.
I use an E4 hacked to be an E8, thx EEVBLOG!

I can see 'internal' cell heat blooms in my automotive battery recovery experiments. Helps to assess soft shorts, hard shorts, arcing etc.
But that's off topic.

 

I would simply use a multimeter on continuity mode/ohms (beeper turned on).
Stick one probe on ground and then probe about till you find a pin/trace that isn't supposed to be connected..

This board looks so simple there is no need for anything "fancier" (FLIR camera..current source,etc... there is no need).

Judging by the very poor quality solder job I see already I'm gonna say the issue is more than likely due to that.. Start with the fine pitch devices first.. Like that micro..

Of course the PCB looks to be of low quality too so I wouldn't be surprised if that could be an issue too..

just with a DMM? to find a pin/trace that isn't supposed to be connected? really? but What about if there isn't any pin/trace that isn't supposed to be connected? dude, sometimes somethings ain't that simple you're thinking.

Unfortunately yes, this is a low quality PCB and for this reason I couldn't solder it better. I agree with you, probably the problem is in soldering and much more probably around the MCU.

...This guy has all the board space in the world and can't even use the proper spacing for component mounting.
He clearly isn't a professional at this so I HIGHLY doubt he has a FLIR around..

If I didn't use whole of the space on the board (or allocating a big space for this job), that's because of some special reasons.

We frequently see; "all the gear...........no idea" on this forum.

Like arab states around the persian gulf! they buy fighters, tanks and etc but never use them.
No, I don't have enough money to buy such stuffs but if I purchase one of them(or anything), I always would use them.

Thanks a lot guys. I'm going to apply this method on my PCB.

 

BOOOOOM! again it's me.
I wired the board to the PSU like this:

I measured the voltage of some junctions due to this picture:

And results:

 

Smaller FLIRs are around $400 these days.
I use an E4 hacked to be an E8, thx EEVBLOG!

I can see 'internal' cell heat blooms in my automotive battery recovery experiments. Helps to assess soft shorts, hard shorts, arcing etc.
But that's off topic.

Maplin had a special offer pyrometer thermometer for £29.95 a few years back.

Nothing as fancy as the pretty pictures you get on a FLIR, but it has an aiming laser to pinpoint any identified hot spot.

 

One of the better lower cost techniques is the tone-milliohmeter. There are a few commercial products and some that you can build. I have something called the "Short-squeak" made long ago by circuit specialists.

 

Could you:
1. post an image of your PCB layout, without the silkscreen, soldermask, and component names?
2. post a schematic?
3. check the soldering near the bottom of the MCU.
4. If you have a scanner available, try to use that to scan high res images of your PCB,

 

This should have been one of the first questions to ask:
What do you mean by "shorted-to-ground"?
What line is shorted to ground?

Or do you mean you cannot program the STM32F103?

I bet you have the chip soldered in the wrong orientation. This happened very recently with another AAC member.

Your photograph is too blurred to see the logo on your chip. From what I can see, you need to rotate the chip 90-degrees clockwise.

 

Maplin had a special offer pyrometer thermometer for £29.95 a few years back.
Nothing as fancy as the pretty pictures you get on a FLIR, but it has an aiming laser to pinpoint any identified hot spot.

I don´t think a thermometer is up to the task, they usually sense with quite a large angle, so the laser just points somewhere in the middle of the field of view plus the parallax at close distances. You won´t be able to pinpoint which part or trace is the culprit. http://www.intech.co.nz/products/temperature/eurotron/Pro-beam.jpg

 

Wait a minute!!! I just read your voltage chart in post #27. Those voltages are way too high. You don't have a short, you have a part in backwards. If you had a short to ground you would be reading millivolts, not volts or even tenths of a volt.

Pull all your parts and ring the board out.

 

After checking the soldering of the MCU I think I found the problem. there were some connections between these pads:

Then I desoldered and soldered the MCU again and sounds like I don't have any problem. I measured the resistance between GND and Vcc(3v3) and there is around 85KOhm resistance between both line. I think there is no probelm Am I right? because when I connect my J-Link to it, Vcc is 2.5v. is everything ok?

 

After checking the soldering of the MCU I think I found the problem. there were some connections between these pads:

That's where a few of us thought the problem might be...

I measured the resistance between GND and Vcc(3v3) and there is around 85KOhm resistance between both line. I think there is no probelm Am I right?

Only a Physic could say.

because when I connect my J-Link to it, Vcc is 2.5v. is everything ok?

If VCC is supposed to be 3.3V, something is wrong; check your power supply voltage.

 

Only a Physic could say.

A Psychic would probably get better results