Why would you want to remain in VNAV PTH when not on the route? The PTH is relevant to the route in the FMC. If longer or shorter it is no longer accurate. If you select DCT TO the first relevant WPT on the expected approach after radar that will give you sensible information, but the radar vectors may take you round the houses to get there. VNAV PTH is a calculated energy profile. The best computer should be between your ears and used very frequently. KISS and use LVL CHG + any DME.
However, back to Alex77. Why were the expected prompts not available? Afraid I can't answer that one. It's a computer and does odd things, just like your laptop. The important thing is not to spend too long wondering why and trying to fix it via the FMC, but go back to basics and control the a/c via basic AFDS modes. VNAV SPD = LVL CHG (at the same speed) any way.
Last edited by RAT 5; 30th Jul 2015 at 14:43.