Build Your Own Arcade Controls Forum

Main => Monitor/Video Forum => Topic started by: michiel on September 25, 2009, 03:55:00 pm

Title: no image
Post by: michiel on September 25, 2009, 03:55:00 pm
Hi all,

I have a original Arcade system with a Jamma 48 in 1 game board.
As the monitor broke I have used it in combination with a VGA monitor connected
to the connector on the circuit board. It has worked in this set-up for a while, but now doesn't anymore however.

Now when the monitor is connected to the board, the system doesn't start at all.
 With the monitor cable removed, it does start, without any visuals off course (I know this because of the game sounds). The main menu and the games all work, however when I connect the monitor, the system dies while lighting a red led on the circuit board. When I disconnect the monitor cable the system boots automatically again.

Is there anyone who has a clue what is causing this?

Thanks in advance!

Michiel
Title: Re: no image
Post by: Kevin Mullins on September 25, 2009, 04:18:38 pm
Have you tried a different monitor ?
Title: Re: no image
Post by: michiel on September 25, 2009, 04:28:39 pm
Yes, with no result.
Title: Re: no image
Post by: Kevin Mullins on September 25, 2009, 05:34:29 pm
Were any settings or dipswitches changed when this happened ?

There is a dipswitch to switch between RGB and VGA.
Switch #2 should be ON for VGA mode.
Title: Re: no image
Post by: michiel on September 26, 2009, 05:59:34 am
nothing was changed.
And switch 2 is ON
Title: Re: no image
Post by: michiel on October 10, 2009, 05:35:36 pm
Swith #1,3 and 4 are off.
Is that ok?
Title: Re: no image
Post by: Kevin Mullins on October 10, 2009, 06:11:42 pm
Yes, those are OK.

#1 Flips the screen
#2 CGA or VGA selection
#3 High Score Saver on or off
#4 Doesn't use
Title: Re: no image
Post by: michiel on November 07, 2009, 03:44:01 pm
Is there someone who have an other idea to solve the above problem...?
Title: Re: no image
Post by: grantspain on November 07, 2009, 04:24:47 pm
maybe something as stupid as low +5 volts or even an issue with earth
Title: Re: no image
Post by: michiel on November 07, 2009, 04:34:43 pm
Thanks for your reaction.
How can i check this.
Title: Re: no image
Post by: grantspain on November 07, 2009, 04:44:36 pm
you would need a multimeter to check both
Title: Re: no image
Post by: michiel on November 07, 2009, 05:19:43 pm
I have a multimeter.
What will i measure...?
Title: Re: no image
Post by: grantspain on November 07, 2009, 05:38:24 pm
check on the jamma connector from pin 1(ground) to pin 3(+5),you should have a minimum of 5.05 and a max of 5.15
if that checks fine then read continuity from the earth point of the cab to the monitor frame,if checking ohms it should be less than 1 ohm(ideally around 0.3)
Title: Re: no image
Post by: michiel on November 07, 2009, 05:45:57 pm
I will check it.
Title: Re: no image
Post by: michiel on November 10, 2009, 03:10:13 pm
The results of measuring are:

From pin 1 to pin 3 =  5.3V
From pin 1 to pin 5 =  5.6V

From earth point to monitor frame = 0.5 ohm

The voltage is to high? :-\ What does this mean?

Gr.
Michiel
Title: Re: no image
Post by: grantspain on November 10, 2009, 04:53:09 pm
you have +5.6v from 1 to 5 or -5.6v?
you +5 is a little high
Title: Re: no image
Post by: michiel on November 12, 2009, 02:52:38 pm
from 1 to 5 is +5.6V

Is that a problem...?
Title: Re: no image
Post by: grantspain on November 12, 2009, 05:01:03 pm
from 1 to 5 is +5.6V

Is that a problem...?
pin 5 should be -5v not +5-disconnect that wire and try
Title: Re: no image
Post by: michiel on November 15, 2009, 03:47:30 pm
If i put the red stick from the multimeter on pin 1 and de black stik on pin 5 it is +5,6V
And black on pin 1 and red on pin 5 is -5.6V

Should red be on pin 1 or pin 5?

The wires  are still connected.
Title: Re: no image
Post by: grantspain on November 16, 2009, 01:50:15 pm
always the black probe(ground) to ground(on jamma pin 1)
Title: Re: no image
Post by: michiel on November 16, 2009, 02:15:40 pm
Ok, with the black probe on pin 1 and de red on pin 5 i measure -5,64V
so that is ok besides it's a little high...?
Title: Re: no image
Post by: grantspain on November 17, 2009, 04:29:26 pm
have you checked a pc lcd monitor on the game board yet?
Title: Re: no image
Post by: michiel on November 19, 2009, 04:08:23 pm
Yes i have tryed my lcd monitor but with the same result... :(
Title: Re: no image
Post by: grantspain on November 19, 2009, 04:14:54 pm
disconnect the -5,check the +12volts
Title: Re: no image
Post by: michiel on November 20, 2009, 04:44:13 pm
how can i check the 12V?
Title: Re: no image
Post by: grantspain on November 20, 2009, 06:00:42 pm
pin 1 = ground
pin 6 = +12v
on the jamma connector
Title: Re: no image
Post by: michiel on November 23, 2009, 04:16:17 pm
pin 6 = 12.32V
Pin 5 is disconnected