On 7 Nov, 20:06, b wrote:
I'm currently trying to fix this ELBE 14" TV, chassis E15.
On power up, all appears well, but after about a minute (less on
subsequent switch-ons) the frame begins to twitch, then (relatively)
slowly squeezes in to the familiar horizontal line.

It sounds like the frame IC overheating, check that it is properly
attached to its heat sink, could also be due to some overload or
overvoltage. Many ICs have a temperature protection that limits the
output current if its internal die gets too hot. I once had this in a
Philips set and had to replace the frame IC, either it was oversensing
the temperature or its internal die fell off from its metal pad.