Cheap mic to record guitars

Unscrew the cap and check the leads. Use a jewelers screwdriver and check the XLR leads. It may just be a cold solder joint.
Also, Shure has a $50 bench fee for dynamics but every time I've sent one back they've just sent me a brand new mic regardless of the age or condition of the mic I sent them. I've done this 10+ times.

Yep and if it is still under warranty and you've got the receipt (2 years) they will send you a brand new mic free of charge.

I just sent in an SM58 that was quite obviously beat to shit on the stage, I mean literally this mic was so wrecked it sounded like a shitty transistor radio (but still under warranty) and they sent me a brand new 58, no charge.
 
+1 on the i5 idea... i like them much more than 57's on guitar cabs and snares. or an e609 all three are awesome mics that you can find used for around $60... i would personally never again buy a shure mic used tho, just because i bought a fake once and it sucked.
 
i5 here is about the same as the sm57.

IBminin any samples of the i5 on guitar?
 
If you download my mesa impulses there's i5 and 57 variants. Personally I prefer the 57 but the i5 is good too.

Your impulses are great man! May I ask a question? Is there an audible difference between the 4 same speakers in the same cab?
 
Gotta say recording guitar is the ONLY pro audio thing that the most commonly used piece of gear is cheap at like 100€/$. Might as well get the industry standard when it's one of the cheapest options out there!