Are the 2k bonus, 4k bonus and 7k bonus lamps working in lamp test mode?
Take the 7k lamp out and measure across the socket again. If it's still 1.5 ohms the socket has a short. If it's open circuit, install a new lamp and remeasure looking for approx 4 ohms.
BTW when you touch both meter leads together in resistance mode what reading do you get?
Quoted from pindude80:
I installed a new socket on wasn't lighting up- the B in the upper saucer, so I grounded the tab and it came on
So that lamp/socket are working you need to go upstream to the lamp driver board.
So ground the anode leg of SCR Q59 (look at the reference links below for SCR leg definitions). If the "B Saucer" lamp illuminates, connection from the SCR to the lamp is ok. If not you have a bad connection somewhere between the lamp board and the lamp.
The methodical approach is:
(1). Ground the tab at the lamp socket. This completes the ground power path to the lamp and bypasses the logic boards. If the lamp illuminates the lamp/socket are ok. If it doesn't illuminate, inspect the lamp/socket.
(2). If point (1) works, then go upstream to the lamp driver board. The anode leg of the associated SCR connects to the tab wire at the lamp socket, so grounding the anode SCR leg completes the ground power path to the lamp. If the respective lamp illuminates, you have good connection from the SCR to the tab wire at the lamp socket. If it doesn't illuminate, inspect the respective crimp terminal at the lamp driver board connector for that lamp and check its pin header soldering for cracks.
(3). Finally if point (2) works, then you can manually switch on the SCR to test the SCR functionality. Connect a jumper wire at TP3 on the lamp driver board. Connect the other end of the jumper wire to the "gate" leg of the SCR. This electronically switches the SCR on. If the lamp doesn't illuminate the SCR is faulty. If it does illuminate then there are other components on the lamp board to investigate, but they are rare failures.
Reference links to the SCR leg definitions: