Bush WS6671 Field Collapse

[AndyH]

Bush WS6671 with field collapse.

Initially an intermittent fault - would either switch on with full picture and then collapse after a 5-10 minutes OR switch on with collapsed field but restore after 5-10 minutes.

Now always collapsed at switch on. Normal picture can usually be temporarily restored by gentle tapping on the SCART connector.

This suggests a bad joint/pcb problem rather than component failure - but any suggestions on precisely where (around which components) to look for this?