Low Power Function Only Decoder problems

[rojoc]

Has anyone built one of these successfully recently?

I only need f0 to provide forward and reverse lighting for example in a dummy HST unit.

I have made a Low Power Function Only Decoder and have problems getting it to work correctly.

I have checked and double checked that the stripboard has no shorts and all diodes are the right way round.

I have also checked all voltages in the build instructions are correct. I am using a PIC12F629.

I am using a Sprog2v3 to test and when track power is supplied I can switch on Output A with f0 and the forward led lights but if I switch from forward to reverse it stays on. Only when I switch f0 off and on again does the Output B reverse led come on.

I then built a second circuit on a breadboard and tried a PIC16F630 as well but it works exactly the same.

Also using the Sprog I cannot read anything from the decoder.

I am using the 629mf.HEX  v2.19 file and have tried using a Pic 150 and a PICkit2 to program the PICs.

Can anyone give me any help in getting this working correctly please?