Having served nearly eight years from the start of the Tom Baker era until the show's twentieth season, the third console was junked due to deterioration and a replacement was made.
Version 4.0 - A Brand New Prop - The Five Doctors
For recording of the 20th Anniversary Special The Five Doctors, Mike Kelt's wish of some investment in the console was granted and a brand new prop was created. The new design was quite a departure from the original and instead of a flat surface with controls attached, the panels had recessed sections. The geometry of the prop was different too, with steeper sides, the underside angled to meet the base, and the base angled too.
There were two types of mould created and three sections cast from each, with the majority of the recesses containing buttons from contemporary computer keyboards. There were a few exceptions and even one or two relics from the previous prop, most notably the five-sided pyramid. Three of the panels had an area for a computer monitor, with two of them actually fitted with working screens mounted inside and powered by BBC Micro graphics. The new console was readied for studio work to begin at Ealing on March 18th 1983.
This prop made its next appearance three months later for Warriors of the Deep at the start of the 21st Season, and it was used again unchanged in the following two stories. By Resurrection of the Daleks, the top of the fragile interior of the central column had become broken and its missing parts can be seen in several shots.
On 9th November 1983 scenes inside the Doctor's TARDIS were recorded for Planet of Fire, and then a couple of days later the console had its edging, spokes and lower hexagons painted black for the prop to appear as the console in the Master's TARDIS.
In mid January 1984 the console was repainted its correct grey to appear in Peter Davison's final fleeting appearance in the TARDIS and production of the season concluded the following month with Colin Baker recording his first serial, The Twin Dilemma. The Sixth Doctor would become the first incarnation since Patrick Troughton not to have a version of the console prop to call his own.
The third full season in which the new prop was used was after the show returned form hiatus with The Trial of a Time Lord. In scenes recorded in 1986. For recording of Terror of the Vervoids the console was used again but on this occasion the five-sided pyramid had been lost, leaving on a set of adhesive pads.
The console saw in a third Doctor with Sylvester McCoy, but after appearances in Season 24, the console room set was junked. The console made a brief return in the final season for the original series, when in Battlefield dark lighting had to be used to disguise the fact that the walls of the TARDIS no longer existed.
And so ends the tale of the console in the classic series. Four different props went through numerous modifications to serve seven Doctors. When Doctor Who returned in 1996 it would have a brand new set and a completely new console design. And when it returned again in 2005, the change would be even more radical - for the first time ever a console was round instead of hexagonal. But even after five decades of changes to the show, the iconic heart of the TARDIS remains fundamentally the same, housed inside an equally iconic blue Police Box.