Outside Column Lights not coming on

[bchhabra]

Hi - New DIYer here. Am an engineer and an electrical hobbyist and a general handyman for my own house for all things mechanical and electrical.

Last week a friend called me over to check why the lights on his driveway entry posts were not coming on when he changed the bulbs. Both fixtures went out at the same time and he assumed it was the bulbs - changed them but no luck. I checked the Voltage and read 30V - it's a regular 120V AC circuit but only getting 30V (AC) at the fixture. The lights are part of a run that also includes two other shrub lights earlier in the run around a circle in the driveway and those two shrub lights are on. The lights are on a 30 year old Intermatic mechanical timer right after the breaker box inside. The timer looks to be OK because it is also feeding the front house lights and when it is mechanically tripped on the front house lights come on fine. He is about 30 min away so I only want to go over once I can get an idea of what could be causing this and how to correct it. What could be possible causes and what would you recommend as next troubleshooting steps?

 

[littlespark]

If the shrub lights are working, then the time clock and supply seem to be ok.

Any problem must be between the the shrub lights and the posts.

Cable buried or accessible?

 

[bchhabra]

If the shrub lights are working, then the time clock and supply seem to be ok.

Any problem must be between the the shrub lights and the posts.

Cable buried or accessible?

The cable is buried but I will check the voltage at the shrub light fixtures and then check the continuity of each conductor of the buried cable from the shrub to the column - however I am assuming if there was no continuity i wouldn't have even received the 30V at the column.. I initially thought there may be a low leakage to ground in the buried cable but shouldn't the GFCI breaker have tripped in that case?