Dear All. I have a problem. My Enterprise machine does not power up anymore I have only one machine .. and for me this is a bad thing as i cannot test SymbOS applications anymore on the real hardware. I have no idea what is going on.


Maybe someone can help me. I have no idea why. The machine was just on my desk all the time without any troubles.

The problem:

If i put the power plug inside the enterprise nothing happens. The RED LED is burning but i have no output picture on my monitor.
Normally you can hear the keyboard sound after a while if you press a key but this is not happening. I only have a black screen on the monitor and that's it. if i power on the system i hear a small 'click' from the speaker. (but that is normal i think)

Maybe.. but I'm not sure anymore i have inserted the monitor cable the wrong way (up side down) But I'm not sure if this can harm the machine. Anyway i think it as it could be that i did it but because i can't remember it anymore I notice it here, as maybe i did it

Other thing is that i did a (volt) measurement on the adapter, which gives me a -12,2 output. On the adapter it is saying that it is 9.5 V so for me this is a bit strange. But I'm not sure what + and - is. (so it could be just +12,2) I have the feeling that the power plug inside part is the - and the outside mantel is the + ?. (But you cannot see it on the adapter)

Other thing is (I'm not an electronic expert) i have this BEEP sound on my multimeter to see if there is a connection between 2 points. If i power off the power adapter and i put  the + and - on the  + and - of the the powerplug it beeps ? (that is not good not?) So maybe i can replace the adapter with an other one but i need to be sure before doing that what is + and what is -

Do you have any suggestions?
 

And do you have any external expansion (EXDOS card, SD interface, etc). If yes then try to remove these.

if i measure the voltage wile the machine is plugged and running it is indeed 9,34 V

No. i selected the right input on the monitor. So i'm sure about that..

I'm not a hardware expert but i can  build in a 7 MHZ kit inside my MSX. I can solder a bit if there is a schematic for it
And i can do some measurements. I will do it carefully.

Between Which PINS i must measure ? Could you give me some hint on that ?

I have on the Controlports 1 and 2, (5V between pin 1 and 2) ( if you look from the back of the machine and it's about the pins on the top)

I have also on the Videoport 12V between pin 2 and 6 from top looked from the back.

Normally you can hear the keyboard sound after a while if you press a key but this is not happening.

Yes, normally you can hear the key click.

And i can do some measurements. I will do it carefully.

Try to measure the RESET pin on the system bus. Normaly it is on +5V, and pressing reset make a 0V pulse.
If it is on constatly 0V then very bad news, it is means the Dave not running

More measurement need a scope.

if wp or basic or exdos etc started

First key click at the ENTERPRISE screen!