Fig.1. - a photo of the rf generator Marconi 2022D before damages.

Opened top part of rf generator. At left rear corner is TCXO oscillator 10 MHz. The TCXO issued no signal. At right is processor board.

Fig.2

On entry processor board was no takt signal for CPU. The TCXO had no output signal, however power supply was OK. Sometimes, usually after a long time the TCXO started and generator initialized quickly.

Fig.3 - The TCXO oscillator on the PCB

Under oscillator are visible test points labeled 1 to 5 related to TCXO pins. At right from TCXO is a header where need to be power supply +5V, ±12V and +24V.

Fig.4 - Removed TCXO from PCB because tests

Under TCXO are wires and space for discrete components. Unlike nothing about this was found in the service manual.

Once we have connected an external signal 10 MHz into test point - output of 10 Mhz signal from TCXO, the rf generator started immediatelly. The problem of generator was found - the TCXO. Now the question - how is damaged the TCXO ?

Fig.5 - Removed TCXO from Marconi 2022D generator.

The TCXO is not working on the desk under external power supply.

Fig.6 - Bottom view to TCXO removed from Marconi 2022D

Fig.7 - Bottom view to TCXO with removed PCB

After removng small screws on both sides is possible to remove printed circuit board, a bottom part of TCXO.

Under the PCB is a soft isolation because the TCXO is heated.

Fig.8

Under soft isolation material is printed circuit board of the oscillator inside the TCXO. Also this PCB is possible to remove up from the TCXO cabinet.

Fig.9 - Removed oscillator. Under metal case is a crystal

On top of the metal case is an adjusting screw. On both sides are power transistors because the heating.

Fig.10 - Removed oscillator

Now the metal case was also removed and the crystal and adjusting trimer are visible.

Fig.11 - A vew to removed oscillator from rear side

The flat cable is broken and it caused the problem of TCXO and the rf generator. The original damaged TCXO is dated to year 1991 and we have replaced it by a new TCXO.