This all depends on what you mean by "obsolete". If your asking "When did firearms replace melee weapons as the dominant military arms", the answer as you guessed, is around the 30 Years War in the mid 17th century. Before then, while many armies incorporated firearms, they were secondary to Pikes and Polearms in military formations. However, the growth of German mercenary companies, generally known as Landsknecht, also saw the growth of gunpowder weaponry. By the end of the 30 Years War in 1648, most armies featured a balance of guns and pikes, perhaps with a slight edge towards guns. Of course this is a pretty generalized answer, and it didnt reflect the development of every army. The Spanish army, for example, remained very pike heavy through the 17th century.

If your question is instead "when were melee weapons completely replaced by firearms?" then there are two answers: The first, and probably least satisfying, is never. Swords, knives, bayonets, spears, and other weapons remain in both the ceremonial as well as functional arsenals of modern militaries across the globe. So in a very real way, melee weapons have never left the military. The other answer, and the one which I think is more in the spirit of your question, is around the beginning of the 18th century and the War of Spanish Succession. During this conflict, or immediately preceding it, many European militaries underwent a major shift in equipment. Previous armies featured a mixture of pikes and guns. The pikes protected the musketeers while they reloaded, while the musketeers used their firepower to break open enemy formations for attacking pikemen. Musketeers could also utilize a defensive instrument called a "plug bayonet" which was basically a big blade that soldiers jammed into the barrels of the guns. This turned their weapons into a crude pike, but the plug bayonets were nearly impossible to remove on the battlefield, and so were neither practical nor popular. At the beginnings of the 18th century, the plug bayonet was replaced by the socket bayonet. This completely changed the way Western Europeans equipped their forces. The socket bayonet allowed a musketeer to both fire their weapon and use the bayonet simultaneously. Rather than having an army split between dedicated pike formations and musketeer, the socket bayonet allowed armies to combine rolls. The musketeer suddenly became capable of not only delivering their traditional range fire, but they could also defend themselves against cavalry and infantry attacks. In the span of about a decade, the pike was replaced by muskets using this new pattern bayonet, and it spelled the end of the widespread use of melee weapons by infantry units. In cavalry units, the lance and saber remained popular until after World War One, while in infantry units the pike and sword were relegated to symbols of rank and office.

Can't offer a comprehensive answer, but your understanding is misguided as pikes remained very relevant and important weapons well into the 17th century. The 1600's is the era of the Tercio and comprehensive "Pike and Shot" formations, where a mix of pikemen and arquebusiers (infantry equipped with arguebus's, an early era muzzle-loaded firearm) were used with great effectiveness. The Tercio would dominate warfare for much of the early and mid 1600's. The famous Thirty Years War was particularly fought mainly by Tercio's and Pike-and-Shot formations. Going into the 1700's, i'm not sure when pikes were officially replaced by bayonets and more advanced firearms, but the pike and the lance are likely the most enduring bladed weapons in history that saw relevance even in the evolving eras of firearms.

In some ways, the legacy of bladed weapons, and pikes in particular, would live on in 18th century and onwards history in the form of the bayonet. The main advantage of the pike was the protection it provided against cavalry and its sheer defensive strengths against infantry charges. As firearms evolved and became better and better, armies would try and keep pikemen in the form of bayonets to still be able to have a resemblance of a defense against cavalry in particular.

Bladed weapons would also survive via the cavalry on the other hand well into the 1800's. Though many cavalrymen would go into battle with several pistols, and some even with a musket or arquebus, the lance, spear, sword, and sabre would remain the main weapons of most cavalries. The Polish Winged Hussars for example, which wore full metal and steel armour in their later variations, would remain relevant and in service until the 1700's. By the late 1700's, and the 1800's, however, the cavalry became weaker and weaker as improved dense rifle formations slowly made cavalry charges obsolete and near suicidal. The Crimean War and the American Civil War helped prove this, and even in the Napoleonic Wars the decline of cavalry was becoming evident.