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[b]How to check a PCB Prototype[/b]

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pucca

Electrical
May 23, 2008
55
Hi! What are the basic steps in order to check your new prototype board? What should you check at first...things like supply, clocks(to see if the board is working and then what)?
Thanks!
 
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That question is extremely open-ended... you check what you need to check, nothing less (and if time is a factor, nothing more).

If it's a small BOM, I solder it all together and plug it in, wait for smoke. If it's a large BOM, I'll put in the power supply circuits (SMPS, linear regulators, etc.) and make sure they're doing their job. Then the large major function chips an test for basic functionality. Protection logic (resistors, diodes, etc.) go in last, and a full bench test is run. A real-world test is the final step, with lots of test equipment hovering around.

Dan - Owner
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Ohmeter before applying power. Make sure connections are really connected and stuff not supposed to be connected (like adjacent pins) is not connected.
 
Opens and shorts are the usual first things to check for. Nothing more silly than to solder up a board and find out there was a massive short in the power planes.

Used to work at a company that didn't test their boards until after assembly. Found out 2 yrs into production that they didn't do much testing after assembly either, since we found a circuit that was shorted on because of a bad layout. Very embarrassing and unbecoming of a high-tech company.

TTFN

FAQ731-376
 
After I do a full visual inspection under a magnifier, I ohm out the various power supplies looking for shorts. Then I do as macgyvers2000 sez.

Keith Cress
kcress -
 
OK thanks guys for the info!
If anyone has a goob manual or book to propose I would appreciate it a lot :)
 
- Visual check, ohmeter before power as said before, always check for open vias under parts before mounting ICs.

When possible, I solder power supply parts first, then plug power and check for right VCC levels before mounting the rest of the BOM.

Clocks, SPI and digital buses often lead to more 'esotheric' failures that are best solved with firmware self-tests, even after the PCB passed all 'copper tests'.
 
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