Being a newbie to this group, I never received any notification of reply, so here I am having a browse through the forum and stumble upon this post… upon reading realise it was my original post.
To anyone who replied, I sincerely thank you, and I have managed to resolve this issue by means of fix, this Is a very common issue on the siemens vdo units both for volvo and for perkins rpm meters.
It involves replacing the lcd display, which is easily obtainable, they are on a ribbon cable and simply pull out and replace.
It’s a little time consuming and you need to be very careful of the PCB board, but it certainly is fixable.
You can find videos on YouTube to assist, and if you attempt and get stuck, give me a shout