Hey.
My final board to fix. I've had a quick look but I'm asking for any pointers to start me off.
6128 mobo.. Press the power button and the LED comes on for half a second. I've measured voltage at the 5v socket and don't seem to get anything. Obviously something, perhaps a short is cutting the power.
There is a jumper on the power switch connector, so the switch isn't a problem.
Have swapped out the easy things first, Z80, 40010 and HAL socketed chips.
Any ideas to start me off?
Probably a short in some chip. Can you monitor the power to see if it's trying to pull a massive amount of current before it shuts down?
It's probably better to be testing this on a bench PSU, if you are using your standard CPC PSU, it may fail from this.
Bryce.
Unfortunately I can't really measure that with the tools I have.
Certainly, if the machine and monitor have not been turned on for a while, the LED is lit for up to 3 seconds before it goes out.
If it's a CPC Monitor the regulator may have failed. Do you have any other PSU to test it with?
Bryce.
I have an mp1 and an mp2 as well as two green screens other than my usual colour monitor. But I've not had a problem with my 464 and 3 other 6128s?
Edit: Tested the mainboard with other monitors and same problem. ::)