The TXE2-specific equipment was different in the TXE2s manufactured by Plessey, STC and GEC, so that spare equipment had to be held for each type of manufacturer. Importantly, each manufacturer made their own reed inserts (reed were manufactured for GEC by their subsidiary, the Mazda Osram Valve Company) and their performance differed significantly in the first years of production. All the TXE2-specific equipment was mounted on slide-in units, mainly single-width, but some double-width. There was a structured holding of maintenance spare units. For those which were likely to be needed frequently or urgently in every exchange, such as a Subscribers Line Unit, a spare unit was held in every exchange. For those units for which a spare was likely to be needed less frequently or urgently, the spares were held at an Area centre serving perhaps 6–10 TXE2s of the same manufacture. Finally for those units for which a spare was likely to be needed seldom, the spare units were held at one centre per Region - there being ten Regions in the UK. In the early (around 1969) Plessey exchanges, a significantly high proportion of the reed-inserts were contaminated with a high-resistance film and were prone to giving an intermittently high-resistance contact. If this occurred in one of the common-control areas of the exchange, it could give rise to the exchange becoming isolated (being unable to set up any calls) for as much as several hours. These faults were very difficult to locate and in the end, the problems were only resolved by a fairly substantial re-reeding programme carried out on the common-control units of the early Plessey exchanges. The STC reeds proved to be more reliable, but, if they failed, they tended to stick or short-circuit. This was also a cause of isolations early on, but a simple modification restricted the most serious type of failure to a small part of the exchange. The GEC/MOV reeds proved to be the most reliable of all. Once the teething troubles had been largely dealt with, which was not until about 1974, the TXE2s realised more of their expected benefits and it was eventually not uncommon for one Technical Officer to maintain the operation of three of these exchanges, serving perhaps some 5,000–6,000 customers in total. In the summer of 2005 a demonstration rack of TXE2 equipment was transferred to the Connected Earth collection at Milton Keynes Museum.