As you should not use violoncello strings ona guitar that would be a common mistake. Never use steel strings on a classical guitar, Steel string tension is much bigger and that may lead you instrument to bend, crack, unglue some parts such as the bridge, and so on. Click here and check how to fix that kind of problem on YouTube: 

• String Musical Instruments cucha as the violin or the cello need a cuvature in the lenght so the fingerboard doesn't touch the strings. For adjusting that we need to remove the strings and use a scraper and measure how much the gap must be made. If there's an old instrument it might be necessary to glue a new fingerboard.

Pegs (or pegboards) for the Bass or guitar) might not be not fitting properly or old. Another thing that may make it hard to make the proper tune is a bad or old nut. For that the pegs must fit properly or might need a new nut.

It is natural that with the variation in humidity and tension of the strings, the instrument's neck bends, we have procedures to return it to its original format. If necessary it will be reinforced, the fingerboard (usually a black piece of Rosewood, ebony, pe, etc.) where the frets of the instrument are located must be made of hard wood to avoid bending, it also improves the sound quality of the instrument.

In musical instruments like the guitar the piece that holds the strings to the top of the instrument is know as brigde. It may have been poorly seated and glued, the glue used may have been inappropriate, among other factors, but no problem, it can be fixed.

The edges on the nut, the saddle or the pegs may cut the string. For that those white parts should be adjusted and replaced if needed. We do not recommend using plastic as it may dry and they avoid the proper tuning as it's usually soft. For the violin the same should be done and we should use hardwood as ebony or rosewood. It can be made of bones or other hard material as well.

Check for leaks, if the low note is not working from that point you might have some leaks. To check if it's working we hit the notes and if you cant's hear a nice tone it's propably leaking. If that's the case we might need to disassemble and check what to do next.

Many elements might trouble the proper tuning. The first are the climate and temperature. The shape of the instrument can be a problem too. Some intruments don't have good quality and a mouthpiece replacement could fix the instrument. Air Leak Fittings might trouble the tuning.

Some stuff might make it rusty (you hard, sea wheather, umidity) and a bad plating. We do plate the instruments in small parts. That's a really tuff job as it mibht trouble the tuning and keys. If that's neeeded we do advivce to use baby powder and to keep your hands clean and dry before playing.