I picked up a SI Deluxe a few weeks ago....and I am greeted with a screen full of garbage.
Here's what I've done so far.....
Tested the +5, - 5 and +12 at the power supply.
First two were fine, 12v read at 10v.
The 18+ read at 15.
Replaced the 12v regulator. Now I have +12 and a little over 17v where I should have 18.
The reset circuit test point reads a nice and high 2.5v instead of .5.
When I force a reset I hear a slight tone/garbage and I get the horizontal lines filled with a ton of dots (assuming a few RAM chips are bad too, I got a Braze kit to diagnose that...but can't get it it to boot.)
Where should I begin? Not sure what needs changed out in the reset circuit and I'm thinking the 8080 may be bad..but cannot confirm.
Here's what I've done so far.....
Tested the +5, - 5 and +12 at the power supply.
First two were fine, 12v read at 10v.
The 18+ read at 15.
Replaced the 12v regulator. Now I have +12 and a little over 17v where I should have 18.
The reset circuit test point reads a nice and high 2.5v instead of .5.
When I force a reset I hear a slight tone/garbage and I get the horizontal lines filled with a ton of dots (assuming a few RAM chips are bad too, I got a Braze kit to diagnose that...but can't get it it to boot.)
Where should I begin? Not sure what needs changed out in the reset circuit and I'm thinking the 8080 may be bad..but cannot confirm.

