how likely is it for a PCB to have solder bridges and still work

[markcoenen]

I.m trouble shooting my first PCB, a power supply for a Samsung p2350 monitor, and
I have found what look like at least 2 solder bridges from the factory. I also see 2 of what I’ll call solder drags. Teardrop shaped solder gobs that point in the same direction. They look like something that might happen when the board went through the solder bath (wave I think). The top of the board has a large arrow and the word “Solder” silk-screened on it also pointing in the same direction. The board also has many lines of solder that look like they are intended to be there. These lines go in both directions north/south & east/west. Some of the lines look like they jump circuit board traces.
I am just starting to learn electronics and don’t have much experience examining PCBs so I am uncertain on how to identify solder errors from legitimate board solder joints.

My questions are:
1) How likely is it for a power supply board to work for a year+ before failing if it has solder bridges?
2) Does anyone know of a resource that pictorially illustrates the kinds of errors that come off the production line and get through quality control?

I’ve included some pictures (the best my camera could do) that show examples.
Thanks for your help.

first 2 pix are bad bridges
next 2 are drags
last 2 are examples of what look like intended bridges

[Agent24]

Re: how likely is it for a PCB to have solder bridges and still work

I can't really see any bridges except between joints that appear to be already connected through the PCB anyway.

It's very unlikely it would work at all, let alone over a year if there was anything actually bridged incorrectly.

Most probably a component has failed somewhere.

[stj]

Re: how likely is it for a PCB to have solder bridges and still work

those "drags" are by design, it's because the boards are wave-soldered.
the "drags" are in the direction the wave travels so it wont leave a big blob on the last contact.

[markcoenen]

Re: how likely is it for a PCB to have solder bridges and still work

Thanks. Your responses are helpful. Having no experience I just wasn't sure if what I saw was ok or not.