How to avoid dishing out the dosh on a dodo. Paul Colbert catalogues disastrous guitar faults that the first-time buyer might miss.

Why is buying your first guitar such a nerve-shredding experience? Fear of being ripped off? Fear of embarrassment from the silvery tongue of the sly dealer? Fear of your newly-acquired 'Beastcat' decomposing on the bus home?

These things we can prevent (well, some of them), in this photographic guide to the danger spots of the electric. These are the sort of faults you might find on a cheap, new guitar, or the signs of strain exhibited by a second-hand one.

Unless it's very serious, then just one of these flaws shouldn't be enough to disqualify any instrument from potential purchase. But two or more and you need to start thinking carefully about how long you want this guitar to last, how much punishment you're going to give it, and whether you'll be relying on a reasonable resale price when the time comes to trade for something new.

As for the sly dealer, armed with these checkpoints you've got valid arguments to level against his convincing ways — the straight ones will agree with you, the dodgy ones will make you look daft, in which case, put the dosh back in the waistcoat.

We'll presume you've plugged the guitar in, played it, made sure you can get some sound and that the strings haven't drawn blood. First, the once-over inspection.

Anything missing? Pickups, knobs and machines are easy to spot but how about all the screws. Is the bolt-on neck held by only three or (shiver) two screws, instead of four? Ask the shop for a replacement bolt and avoid weakness (in your guitar and your demands). (Pic 1.)

If there's a screw missing from one of the machine heads, the winder may well stay on the headstock but it could twist out of line as the pull of the string spins it around. It won't make tuning any easier, and it will spoil the symmetrical visuals. (Pic 2.)

Check that each of the saddles on the bridge has an intonation screw — that's the one which passes, horizontally, through the middle of the saddle and usually appears at the tail end of the bridge. If any are missing, you'll be reduced to ramming slivers of silver paper into the gaps to keep the saddles in place and the guitar in tune.

Do the pick-ups have adjustment screws on both sides, have any pole-pieces gone AWOL, if the bridge is raised by two knurled wheels on pillars underneath, do these knurly things really exist?

Finally, do any of the important bolts and bits, like those holding the neck in place, show signs of misuse or are badly burred. Could indicate that a lot of (not necessarily qualified) tinkering has been going on, and any of your own repairs will be resultingly trickier to carry out. (Pic 3.)

Now the deeper inspection when we start wiggling things. Kick off with the G-string machine head (D on a bass) on those guitars with three machines on each side of the headstock. (Les Paul-ish). If the guitar's been dropped at some time, this is invariably the protruding gizmo that cops the impact. If the machine is loose or wonky this could be the sign of an incautious previous owner. Guitars don't often drop in the other direction — Lord knows why — but you could double check the D just in case.

Give the pick-ups a firm poke, if they drop into the guitar body, smile innocently. Tug on all the controls, if the knobs come off in your hand, well, no sweat, but at least you know to keep them in your pocket on the way home instead of scattering them through the Underground.

Pull on the strap buttons — if they give perceptibly, don't start duck-walking around the stage until they're tightened up, with filler in the holes, if required.

Lastly, with the guitar sitting on your lap in the playing position (not flat), attempt, gently to move the neck vertically up and down to test the fit and strength of the neck/body joint. Some slight give should be expected but if you feel it creak and shift substantially (¼in or more at the headstock end) this could mean trouble IF you're going to be subjecting the guitar to hectic stage manipulations. A gentle home-recordist might never know.

'Tell me sir, is anything worn under the kilt?' 'No it's all in perfect working order'... and other jokes of the Byzantine era. Wear and tear will obviously show on secondhand instruments but when does it become frightening?

Under the flag of 'easily-replaceable' we can put nuts (cuts too deep or wide, or padded out with foil) and the saddles of acoustics (rubbed flat in profile instead of coming to a point, chipped or lacking in nicks to hold the strings). (Pics 4 & 5.) More a sign of uncaring ownership than dire danger. Do beware of acoustics with high actions and low saddles — there might not be any adjustment left.

Lumps out of the paintwork, specks of rust, spots of blood, all of these are up to your own judgement on aesthetic value. More serious signs of wear tend to occur on older 'name' guitars — a battered but lovable Tele or Strat perhaps. Like a car with a high mileage it may be running beautifully now, but its life expectancy could be short, and eventual repairs turn out expensive, that's if they haven't already been carried out! Viz.

Frets that have been continually 'stoned' (filed down to lower the action) will be flat, like Belgium. You could then have trouble with the intonation as the string is sounding on a broad expanse of metal instead of a precise peak. The frets themselves may also be on their last legs.

One tell-tale sign of an instrument that's already been refretted is to see where the tang (the stem beneath the fret) stops in the wood. If it goes beyond the fingerboard and touches the neck itself, then you've been refretted. (Pic 6.)

Again, not a bad thing, providing the job's been done well. Check all the frets to see if any are lifting away from the fingerboard. If you can slide a fingernail into any gap between the underside of the fret and the timber of the fingerboard... that nail and the body attached should not be gleeful.

Now here's a mind-tingling tip. If possible, compare the guitar you're scheming for against another identical model (maybe from a brochure shot). Has the previous owner treated it to any additional cosmetics? Yes? Then be suspicious. Consider this story. A bass player took his four string to a repairer to have the rear of the neck thinned down. When returned, he found the back of the neck had been treated to an extra, attractive, black stripe between the two original decorative lines. Today the bass is on a different repairman's table. The strip and the lacquer have cracked away revealing the bare metal of the truss rod. So much timber had been shaved away on the original job, the rod had come to the surface and the strip had been added to cover it up.

Horrified? Don't tremble too violently. The quality of budget Japanese instruments in particular has improved phenomenally in the last half-dozen years. This checklist is more likely to help you spot nasties by previous owners, delivery men and ill-qualified repairers than shoddy workmanship at the factory — though you never know.

In conclusion, there are the hoary old problems of action, playability and neck deformation. The pictures present a clearer idea of what you might reasonably expect in terms of action (a matchstick just held between 12th fret and the top E string is the traditional judgement of action acceptability). (Pic 7 = good, 8 doesn't.)

There's no substitute for taking a knowledgeable mate along with you to check out the goods, but if you are alone, try this exercise. Press down the top E at the first fret AND the last fret, and see how much clearance that leaves you between the E and all the other frets. If the string is touching frets all the way along, the neck could be warped, or the truss rod wound too tightly. If you can repeat the matchstick trick in several places there's too little truss tension or the neck might be distorted in the opposite direction. The first example is the deadliest because if the truss rod is already completely slack there's nothing you'll be able to do about it.

And DON'T fall for the old chestnut of looking down the neck to ensure it's perfectly straight — it shouldn't be. There ought to be a fractional bend (with the dip in the middle) which is termed neck relief and that gives the strings room to vibrate without clanging against the frets.

Thanks to TUNE INN, Hither Green Lane, Catford for keeping these OFF the sales wall.