Zac Time Machine has died

[63wizz]

I have done the repairs to the acid damage area, the board seems to boot every time now, the LED comes on and stays on.
All the playfield lights flash normal in attract mode.
But no buttons do anything, so i guess the machine needs re programing.
So i switch the #4 switch over on the MPU board and turn the game on, it starts to make a continuous sound, i thought i read somewhere that it is supposed to make 4 or 5 bing bing noises.
so then i press the advance test switch and nothing happens, i think there is a switch matrix problem as the tilt is in the same row and tilting the machine started my problems.
All the coin door wiring has been hacked but the advance test switch worked before these problems happened.
I have replaced ic38 a 3081 and ic41 a 4028 but this has not helped there is a 4042 chip i could replace next.

Ian

[goodolddays]

Gday Ian . Great to hear you have made good progress. Keep at it , you will nail it soon. 

[63wizz]

OK.. CPU isnt booting.. its trying hard to though.
The logic voltage on Zacs is a little higher than normal, but all the IC's are well within range and youll find that the voltage drops as it fans out through the board.
The RAMs are right in the corrosion zone.. the pads will be the main issue IF it is corosion that is the problem here.. we havent determined that yet.
The 2 RAms are a bugger of a job... pulling off a socket will do some damage to what could be a delicate area.. this will need to be repaired.
The cct between the 2 RAMs i didnt enjoy rebuilding, but in all honesty it took maybe 2 hrs tops
R1, D1 and D2 cop a flogging with corrosion too.
Theres a large ground path at battery -ve.. mine was eaten away and all R2 - R9 had floating pads... check all this.. buzz it out well, its all one of those jobs that you dont want to have to go back to.

In all honesty, your CPU was booting - now its not, but it is continually trying, not just locked off..
Have you checked all signals on the 2650 CPU?.. This can give very big clues as to why its not booting.
Check that you have signals on data bus on 2650.. anything missing and strongly suspect broken traces or socket fault on Eprom to CPU.
A logic probe is excellent for zac games.. apply to pin 10 IC5 ( 2114 RAM).. make sure its pulsing... then CPU pin 23.. same signal.. should be pulsing.

Id say.. do all this on the bench.. the board seems happier there

Still no joy with this board. The board is booting every time according to the LED, which is on constant.
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.
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.
The score displays are on zero and the credit display alternates between 4000000 and  two zeros on the left and one zero on the right.
The PF lights are in there attract pattern.
So basically it looks like it should work but i cant get into the test program mode.
if any one has any suggestions please, i need help with this one.

Ian

edit: added youtube vid of machine with switch 4 on

[63wizz]

OK its running again, and most of it was my fault.

I replaced TR3 a BC548 transistor with a 2N3904 when the original problems started, Yes this transistor is a  replacement for the BC548 BUT the leg pinout is reversed, so i put it in the correct way but really this was the wrong way.
So in goes a new 2N3904 back to front and i have my coin door switches back again.
Re programed the Time Machine and she goes

I think what started this whole saga was the battery acid corrosion and should have been the first thing i fixed

Thanks to all who offered suggestions on fixing this pin

Ian

[Retropin]

Interesting....

I have a similar problem with my Devil Riders... everything works in test mode, but in game mode, ball does not kick out, bumpers are dead etc. I have switch inputs to the board but no output.

I ran Leons test program for zaccaria and all switches strobe as normal BAR the output for TR3 which is in reverse.
Yet TR3 tests fine and is installed correctly... have replaced the 4028 that feeds this also, but no luck.

You can see now why i didnt reply any further on this thread... i have almost the same problem!

[63wizz]

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.