black screen on siemens sinumerik 810m

[Rasmusholm74]

hello

I have a omz m40cnc with a Siemens sinumrik 810m, there is only black screen when I start up the machine. what can be wrong?

[thelonegunmen]

we have a couple of machines with sinumerik 840 i have seen a black screen only once and i had to replace the monitor not sure if your control lets you turn off the screen or not i know some of our other machines will let you turn off the monitor.
make sure your cables are all tight

sorry i can't offer more

[Sinumeriko]

The 810M that he's talking about still had the old type CRT monitor. This is what I'd try, in order to diagnose the fault:

Looking from behind the cnc, the pcb that's right next to the monitor is the video card, between them there is a gray cable with a 10-pin or so connector, unplug it and turn the machine ON again, if you see a green square (or orange, depending on the year of your Sinumerik) filling the whole screen, then your monitor is ok but your video card might be at fault.

Another test would be to check if the CRT monitor is getting the +24 volts from the underneath power supply, this can be measured at the red and black wires between these 2 components. If that voltage is ok, take the monitor back cover off, try to see the yellow light coming out of the CRT filament, if it lights ok, then your monitor might be at fault.

Of course I am assuming that you made sure the leds on top of the Sinumerik lite up a second as they regularly do at starup, because if they don't, then your Sinumerik could have another kind of failure, not necessarily a bad monitor.

[Rasmusholm74]

thanks I will see if it can help me and I will return

[Rasmusholm74]

the leds on top of the Sinumerik lite not up a second as they regularly do at starup.....
i hope you can help me

[Sinumeriko]

Ok then you might have a different problem there. Turn your Sinumerik ON while holding down the key that has a symbol that looks like an eyeball, the screen will show information after a few seconds, release the key now. Try pressing down ONLY the SOFTKEY that says something like SETUP END PASSWORD. That should reset your Sinumerik without touching any basic information, if no further problems, that should be enough to fix your machine.

Please don't click on any other SOFTKEYS now, or you could erase important data inside your cnc. Keep us posted.

[Rasmusholm74]

nothing happens when I hold this button down ... only black screen

[Sinumeriko]

Does your machine actually turn ON, the machine side (hydraulics, etc)?

You must have +24 vdc and a NC START PULSE at the back of the Sinumerik (orange/green connectors). If so, when you turn the machine ON, do you see a red led at the back of the cnc, in the CPU board? Is it ON all the time?

[Rasmusholm74]

Yes the machine turn ON, the machine side bot not the bottens on the External machine control panel.....

+24 vdc and a NC START PULSE at the back of the Sinumerik (orange/green connectors). I dont no but i will find out tomorrow....

the red led on the CPU board ist not ON all the time.

[Sinumeriko]

"the red led on the CPU board ist not ON all the time"...

But does this cpu led ever turn ON?

I need to know if it turns ON and then OFF, after a few seconds, that would mean that your cpu is ok.

[Rasmusholm74]

I've just found out that the red led on the CPU board ist not turn ON and then OFF, after a few seconds.... it turns ON when I press the nc start butten and stays on.....

[Sinumeriko]

Ok, with the machine OFF, take out the video board, it is the one that's next to the crt monitor, now turn the machine ON again and with the board being pullet out see how the cpu red led behaves and tell me.

[Rasmusholm74]

it is the same, without the video card.

[Rasmusholm74]

who knows anything about how to connect the cable between Siemens Sinumerik 810M operator panel and the External machine control panel ???

[duduslaw]

Problem solved?

[Rasmusholm74]

nope

[vavco]

Hi there , If there is a classic CRT monitor, I think it could be the same problem as I had solved two times. It was a longer time ago , as I remember the problem was situated in a horizontal part of the monitor .( high voltage transformer and its circuits ) There is capacitor - marked C143 , 4,7uF / 100 V ??? [according to my record] on the board and if its capacity is smaller , driving transistor for HV transformer is driven not enough to shine the screen up. So , replace it to fix it. I hope it could help. Take care .