What to look at

Straightness;

The neck

Warped;

The frets

Fretboard;

The headstock;

There are a few points you have too keep in mind when you are buying a secondhand guitar.

The most important is the condition of the neck, is the neck still straight and not warped, the condition of the fretwork

You can check the straightness by looking at it from the side and comparing it to the strings (always a straight line), if you see a small lowering curve or the neck is dead straight that’s good.

most guitars have that curve original, but if you see a upward curve or even worse a wave in the neck, that’s not good.

Guitars with waved necks don’t buy them !!( Very expensive to repair)

Even a extreme curve both ways is with a lot of patience mostly to undo.

To check if a neck warped is, look form the bottom of the guitar to the neck , the frets have to be in one line with each other, just like you look down a railway.

Looks it like they are out of line most likely the neck is warped, mostly can’t be repaired (can sometimes be done by a pro and is expensive) sometimes this happens due to a over tightened trusrod.

I personally wouldn’t buy a guitar like that.

Always check the frets for fretwear , dents in the frets etc.

Refretting is a difficult job especial on a neck with a binding which makes it also a expensive repair by a pro.

sometimes the frets are getting loose mostly you see that at old guitars with a dried out fretboard, a loose fret is no big problem i always let a drop of superglue run under it and just press the fret down, works for me.

Sharp frets are easy to file down with a small iron file, sometimes oiling the fretboard is enough, the fretboard can be so dried out that it shrunk, by oiling the fretboard the wood swells a little bit and covers the frets again.

Sometimes the fretboard is missing small pieces or even is due to a lot of playing worn down that much that there are dents in it.

Doesn’t have to be a big problem, if the guitar still plays alright and it doesn’t bother you.

Don’t buy that guitar if you have issues with that, and it influenses the playabillety it’s a expensive repair or, you have to be skilled and daring enough to try to repair it your selfs.

Also you need some special tools for it to repair such a damage, radius sanding blocs, and all the stuff you need to do a refret..

Such thing you better try to learn it on a old worthless cheap acoustic guitar.

Do you mess that up no problem, but don’t try it on your main axe.

Also important that there are no fretmarkers (inlay) missing or damaged, it’s repairable but not a easy job.

Sometimes a inlay has come loose, that is easy to repair with a drop of superglue.

Always check the headstock for cracks, in the length is not a big problem ( if their not too big) but from side to side or diagonal is.

Is there a crack in the length near a tuner that’s something different be careful with it.

what kind of tuners are on it and in which condition?

Tuners are not that expensive too replace so don’t let a good guitar pass you by because of bad tuners.

It is a point to get the price down though.

For a collector it’s important that the tuners are original, but if you want to use the guitar on stage a set of good tuners are more important.

Finally check the neck for cracks same story as the headstock in the length not nice too look it but quite harmless, sideways and diagonal, don’t buy.

The last thing, tap on the neck and listen for rattling sounds, can be a loose tuner ring but also indicate a broken trusrod, in the last case don’t buy.

If the neck is bolt on the neck can easy be replaced a set neck or neckthrough don’t give this option.

On a set neck the neck can be replaced by a pro, but this iws a very timeconsuming and difficult job, so also a expensive one, and not every guitarbuilder/repairer  will take a job like this on.