m_thompson
Veteran Member
About 10 months ago the +5 output in the H724 power supply went out of regulation, tripped the Crowbar, and blew the 25A fuse. The LM723 regulator IC on the A2 regulator board had died. Replacing the LM723 fixed the +5V output.
Last week while I was replacing the front panel plexi and bulbs the -15 supply died. The -15 supply also uses an LM723. This one had rusty leads, so I replaced it. It didn't change the -15V behavior so I connected a clip lead to each pin on the LM723 to measure the voltages. After removing the A2 board for about the fifth time the -15 started working. Maybe the connector for the A2 regulator was dirty?
The system is back together and working OK. Now I can go back to work on the RK05 drive, and the RK8E controller. The M7104 board in the RK8E had a 100ns delay line glued on as an ECO. The delay line was ripped off before I got the board, but I have a tube of them. Debugging the RK8E should be lots of fun.
Last week while I was replacing the front panel plexi and bulbs the -15 supply died. The -15 supply also uses an LM723. This one had rusty leads, so I replaced it. It didn't change the -15V behavior so I connected a clip lead to each pin on the LM723 to measure the voltages. After removing the A2 board for about the fifth time the -15 started working. Maybe the connector for the A2 regulator was dirty?
The system is back together and working OK. Now I can go back to work on the RK05 drive, and the RK8E controller. The M7104 board in the RK8E had a 100ns delay line glued on as an ECO. The delay line was ripped off before I got the board, but I have a tube of them. Debugging the RK8E should be lots of fun.