knight rider
Member
Ok, have the space invaders power supply board. Having a small problem and driving me nuts
>The -5 volts pot won't adjust any lower than -6.25 but will adjust higher into the -7 and -8 range. I cannot get it to go down any farther, I need -5
>The +12 volts pot won't adjust any higher than +9.54volts, it will adjust down very little to +9.45, but thats it. It will not adjust any higher, I need 12 volts
>The +5 volts...all good,works perfect
Now, I have changed all the caps...all 3 pots...the 2n3055...and both regulators on the end 7905, and 7812
I checked the diodes on the left side of the board and as far as I can tell the check good with the multi meter.
I am stumped, lost, Is there something I am just missing starring at me in the face? Something simple I missed?
Any help would be great
Thanks John
>The -5 volts pot won't adjust any lower than -6.25 but will adjust higher into the -7 and -8 range. I cannot get it to go down any farther, I need -5
>The +12 volts pot won't adjust any higher than +9.54volts, it will adjust down very little to +9.45, but thats it. It will not adjust any higher, I need 12 volts
>The +5 volts...all good,works perfect
Now, I have changed all the caps...all 3 pots...the 2n3055...and both regulators on the end 7905, and 7812
I checked the diodes on the left side of the board and as far as I can tell the check good with the multi meter.
I am stumped, lost, Is there something I am just missing starring at me in the face? Something simple I missed?
Any help would be great
Thanks John
