My hps140i has stopped measuring dc in dc mode and fails the self test is there anything I can do?
Sorry, the unit is not user servicable.
You can return it for inspection to your distributor or direct to:
Velleman Tech. Dept.
Legen Heirweg 33
9890 Gavere
Belgium
Is it liable to cost a lot to fix or is it just worth getting another one. I think it is out of warranty but I will check.
Repair is always less than the price of a new unit.
Ok,
The problem was RY3 was open circuit even with 5 volt appied. I replaced this and all works ok cost £1.50. I must admit I broke the screen in the process 
and got a new one from RS for £12.00. All works now thanks.
Robert