VF1 Low Voltage Power Supply Problems.

[Bruce_Mowbray]

I think I'm having a problem with my low voltage power supply. Here's the scenario:

Turned machine on. No problems. Did a manual tool change and it went well. Went to do another manual tool change and the screen said "please wait" at the lower left corner. Then the screen went entirely blank. I tried to get something to happen on the keyboard and got nothing. No beeps. No actions. Nothing. I turned off the machine at the control panel (HARD POWER OFF). Powered up again. The contactors came on. Fans and spindle drive came on. CRT monitor light came on but still a blank screen and no results from pushing keys or buttons. Powered down again. Opened back cabinet and powered back on. No LEDs on main PCB are on. Not even the "5 volt" low voltage supply light came on. The unusual thing was the faint clicking sound coming from the low voltage power supply. I powered down again and the clicking sound went away as the control powered down.I checked the fuses and found the FU3 was blown. Replaced that and powered up but no change. Powered down and rechecked fuse. All are OK. I am stumped.

So. What do the masses think the problem is? I am leaning towards the low voltage power supply unit. Is there a way to check this without getting a new one? I've done some micro electronic work before and was just wondering if I'm wasting my time. Thanks in advance,

Bruce Mowbray
Springville, PA

[JoBwan]

Sounds to me that if the 5 volt kight did not come on, you should check with a multimeter to see if you actually have 5 volts and 12 volts coming out of the power supply. This will tell you if it is in fact, a bad unit. Hope this helps.

[Al_The_Man]

Disconnect the load side and with it powered up, check the output voltage, maybe a loading problem.
Al.

[tsbfishing1]

It might be the low voltage power supply board.It happen to me about 2 years ago .