Here is an email i sent to David Gersic,because of this email i went back to the TR3 and found my mistake
Ian
On Monday 11 April 2011 05:47:14 you wrote:
> > Hi David, i am having problems with my Time Machine. The board is
> > booting every time according to the LED, which is on constant.(i have
> > fixed the acid damaged area)
If you have the LED on, and the score displays working, the board is running.
So that's a good sign.
> > None of the cabinet switches do anything.
> > Switch 4 on the cpu board turned to the on position makes the machine
> > make a constant noise, but the advance test button does nothing.
The DIP switches are completely separate from the switch matrix. So that
switch 4 works is interesting, but not all that helpful.
The switch matrix strobes on the Rows. Row 0 has it's own transistor. Rows 1-7
are from IC38. Row 0 is the coin door switches. So, possibly TR3 is bad (no
Row 0, no coin door switches). Without the coin door switches, no switch test,
so it's kinda hard to tell if any of the others is working. You might put a
logic probe or 'scope on Row 0 to see if there's any strobing activity there.
If there isn't, then work back through IC41, IC33, and IC32 / IC19 / IC31 to
find out why not. If there is, then your problem is on the read side of
things.
To read the switch matrix, IC25 and IC24 must be working, in addition to IC32,
IC19, and IC31. But without knowing if you have the strobes on the Rows, it's
impossible to know if the reads on the Columns are working or not.
> > I have replaced IC5 IC8 IC17 IC19 IC20 IC33 IC38 and IC41, this has made
> > no difference.
> > I have tested the Data bus and the Address bus, everything seems to be
> > ok, i dont have a logic probe only a DMM.
You'll need at least a logic probe to do any useful debugging, really. A DMM
isn't going to help much.
IC5, IC8, IC17, IC19, IC20 are all unrelated to the switch matrix. IC33, IC41,
and IC38 are, as above, part of the strobes. TR3 isn't in your list, though,
so that may be relevant, but it's hard to say that for sure without some kind
of test equipment to see what's going on at the input of TR3 (from IC41) and
its output.
> > So basically it looks like it should work but i cant get into the test
> > program mode.
You're sure there's no break in the wiring harness or bad connections between
the coin door and the boards? What happens if you put a jumper wire across
CN10 pin 6 and CN10 pin 10? That would be the "advance" switch. If that works,
your problem is in the wiring, not the boards. If it doesn't, well, it's on
the board.
> > Originally i was playing a game and the ball jumped through the gate
> > and in behined the mini PF which was in the up position,
> > so i thought i would tilt the machine so when it started up again the
> > mini PF would go down and release the ball,
> > all the score displays started flashing on and off and the game did not
> > come back on to continue play.
> > The game has not worked since.
Weird. Shouldn't be related, though.
