Analogue-sequencer

On 9 Apr 2004 at 9:06, blip wrote:

> got a new power supply and a new voltage regulator... and *nothing.* i get
> voltage across D6, but nothing else... i get erratic readings from the
> voltage regulator... either zero or a number that fluctuates beneath 1
> volt...

Still sounds like you've got a near short on the output of the regulator, i.e. something 
is pulling too much current. Have you tried powering up the board without the IDC 
connectors plugged in? Do that, then measure the regulator output. If it's still low, 
then you know it's a problem on the Main board and not with the ancillary boards or 
ribbons.

If the result indicates that the main board is at fault, and you have soldered all the ICs 
in place; check your soldering very carefully. Look out for any solder bridges or 
splashes which may be making unwanted connections. If you have socketed your 
ICs, then remove them all, then power up the board, and measure the regulator 
output again. Check and recheck that *ALL* your ics are inserted the right way round.

Foe guidance, refer to the picture at the bottom of this page:

http://www.colinfraser.com/p3/p3-build.htm

Once you've checked it, get someone else to check it again, if you can. A fresh pair 
of eyes can work wonders.


 A backwards IC could easily produce the symptoms you describe.

> 
> i now have no clue what to do...

Don't give up. It's well worth the effort.

All the best

Andy
--
Andy Wilson
http://www.techman.synth.net
mailto:andy@techman.synth.net