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I'm rather a newbie regarding electronics but I came here to seek for a simple response.

I realized that a electronic appliance I have doesn't work anymore. I tried to investigate the issue and found that a SMD component was missing.

Starting from this I searched for the schematic and found the missing piece, which is a SMD 33pf 5% 25V 0201 capacitor as shown here:

enter image description here

Now, I don't have a replacement part and in any case I wouldn't know how to solder a SMD component (I have a rather old and standard soldering iron) so I was wondering if short-circuiting the connection could do anything useful or tragic.

The missing piece is evidenced here:

enter image description here

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  • \$\begingroup\$ If its missing its most likely that it was never there in the first place. Unpopulated components are common. \$\endgroup\$
    – Passerby
    Commented Mar 3, 2015 at 2:32
  • \$\begingroup\$ @Passerby: Actually I can see the soldering pads but I definitely don't know if an unpopulated component would have them anyway, even just unconnected like in the picture I added. \$\endgroup\$
    – Jack
    Commented Mar 3, 2015 at 2:36
  • \$\begingroup\$ A random pcb. notice the missing parts still have solder pads. sphere.ws/blog/wp-content/uploads/2008/07/… \$\endgroup\$
    – Passerby
    Commented Mar 3, 2015 at 2:40
  • \$\begingroup\$ See my addition - are the pins offset? \$\endgroup\$
    – Russell McMahon ♦
    Commented Mar 3, 2015 at 7:33

2 Answers 2

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Shorting would be tragic, also it says "no stuff" which means do not install so likely it came without that cap in place.

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Definitely tragic.
The line is evidently a signal line of some sort - horting it to ground would ensue that it was a signal line of no sort.

"NO STUFF"means "do not install". It was probably a "design kluge" which was found unnecessary.

It is possible but unlikely that you will find a fault by visual inspection.
The most likely fix that may work is to carefully resolder all joints. Use very fine solder and heat the joint just enough to flow solder onto the joint - or use NO solder and just reflow the joints. This will fix some boards which had a problem initially but soldiered on for days months or years. But, the chances of fixing anything like this without a degree of specialist knowledge is reasonably small.
But, do try - you'll probably learn something.

ADDED

It MAY be an optical illusion but the IC at the bottom of your photos appears to be badly offset. The red lines at the top are along tracks from the small components (probably resistors).

At bottom either the red lines or the green lines are along the centres of the pins.
IF the red lines are along pin centres then the IC is offset to the right by about 1/2 a pin spacing and would be in immense danger of making wrong or no contact on some pins.
If the pin centres are along the green lines then all is well.

IF the red lines are thepin centres then inspecting the IC pins and ensuring all are properly soldered to where they should be, and tyhat none are soldered to 1 pad across MAY solve your problem.

So, red or green ?

enter image description here

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  • \$\begingroup\$ Randomly re-soldering 0201 and 01005 parts sounds way too instructive.. \$\endgroup\$
    – Spehro 'speff' Pefhany
    Commented Mar 3, 2015 at 2:52
  • \$\begingroup\$ @SpehroPefhany Probably. It's dead now. A conscientious beginner just reflowing parts one end at a time has some hope. | I have more hope re the offset pins. My brain says the yellow projections MUST be pins as they line up well, but I see what looks like pins at 1/2 a pin offset. Something is fooling my eyes/brain. IF the IC was offset ~ half a pin and soldered so it worked it would be very marginal. | How do you see the pins? (yellow dress or blue dress?) \$\endgroup\$
    – Russell McMahon ♦
    Commented Mar 3, 2015 at 7:55
  • \$\begingroup\$ I don't think that the IC is offset. The red lines at the bottom are on that silver background, which encloses the IC even at the short side. Also, the distance of the right "red" pin to the edge of the package is unnaturally small compared to the distance between pins. \$\endgroup\$
    – sweber
    Commented Mar 3, 2015 at 9:33
  • \$\begingroup\$ @RussellMcMahon thanks for your addition, the pins are the green lines indeed, so I guess I'm out of luck! In any case I wouldn't be able to resolder anything so small with my current equipment. \$\endgroup\$
    – Jack
    Commented Mar 3, 2015 at 14:02

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