pcb or monitor question

darer234

New member
Joined
May 26, 2010
Messages
69
Reaction score
0
Location
Thibodaux, Louisiana
Ok so i am very new to this and trying to find out if my monitor is damaged or my pcb.

if the pcb is in fact working and i have the 5v terminal on the power supply actually putting out the correct voltage, can i disconnect the 12v so the monitor is not recieving any power,

would i hypothectically hear the game sounds if the pcb is in fact working?

or will the game not work at all this way?

i ask this because when i try to adjust the 5v it throws the 12v off and vice versa, so i figure if i can get one right i will know what it is for sure
 
if ya turn it on and ya hear game sounds but get no picture then ya what's called a game that " plays blind " . 99% of the time that means ya got monitor issue's.
 
The 5vdc is regulated and the 12vdc is not. Adjust the 5vdc to be in the desired range and don't worry about the 12vdc unless it is above 14 or 15 volts.
 
Just to add.....the 12V lug has nothing to do with operating the monitor. Your monitor is running on 120VAC.....unless it's some of the Asian monitors (which operate at 100VAC)......or if you're in a country that operates on 220/240 volts AC.

Edward
 
Just to add.....the 12V lug has nothing to do with operating the monitor. Your monitor is running on 120VAC.....unless it's some of the Asian monitors (which operate at 100VAC)......or if you're in a country that operates on 220/240 volts AC.

Edward

Glad someone here is paying attention.

Your +5 is normally used for board operation, and your +12 is is for your sound, although some games need +12 and -5 to operate.

It is quite normal for the +12 or -5 to move while adjusting your +5. I've seen many boards work just fine with the +12 reading as low as +10.7 or as high as +13.6. The important voltage is the +5, and you should have it set around +5.15, although a few boards may need it higher, but you should verify that here before adjusting it higher, as it could damage your board.

And it would help if you would tell us what game PCB you have, as that can help us be more specific in helping you...
 
Hi, this is the ikari warriors that I am fighting with in my other post,
http://forums.arcade-museum.com/showthread.php?t=136181


I have got a new PCB and power supply on the way to try to get this thing going.

I was having blue spark problems in the tube, but I think that was because the power supply was giving like 15v to the 12v so no telling what the 120v was. I guess I could check that as well. I never checked any voltages on the bottom 3 terminals.

keep in mind I got this whole game for 15$

I ended up paying 75$ for a verified working PCB and power supply with shipping.

A little high, i know, i just didnt know that then and was anxious to get my first cab working.
 
Last edited:
Hi, this is the ikari warriors that I am fighting with in my other post,
http://forums.arcade-museum.com/showthread.php?t=136181


I have got a new PCB and power supply on the way to try to get this thing going.

I was having blue spark problems in the tube, but I think that was because the power supply was giving like 15v to the 12v so no telling what the 120v was. I guess I could check that as well. I never checked any voltages on the bottom 3 terminals.

keep in mind I got this whole game for 15$

I ended up paying 75$ for a verified working PCB and power supply with shipping.

A little high, i know, i just didnt know that then and was anxious to get my first cab working.

I wouldn't say $75 for a working board and power supply is high. New power supplies can cost $25 or more, and working boards often cost $50 or more. Sounds normal to me....
 
hmm. I guess I just could have found a better deal. I had a guy offer me a board for 30.00 shipped, but its all good.

As long as this monitor doesnt need to be replaced, I have a totally working cab for $100.00 even.
 
I was having blue spark problems in the tube, but I think that was because the power supply was giving like 15v to the 12v


Your power supply has nothing to do with the monitor. They are not connected to each other.

Edward
 
ok now i am defnitly confused.
The switching power supply doesn't power the montior?

What does, the power from the wall?

the cord comes from the wall, goes to my switch, and then to the power supply to switch it to dc. But that is only for the board?

So the transformer( or whatever its called, the other thing that is screwed to the bottom of the cab besides the power supply) powers the monitor?

Do you think the transformer is bad then?

As I said when i first got this thing home from the thrift store and wired the plug up it came on and then screen worked, it just gave me a rom1 error, so i took the board out and reseated the chips, in doing so i broke 3 of the legs off of chip a 5004-1, so i got a blank chip, stole 3 legs from it and soldered them on and replaced the chip back in the socket.

Now this is what I get.

The monitor is getting power, but nothing shows on the screen, no game sounds(even though i replaced the speaker.)


edit: just put the multimeter to the power supply once again.

My power supply has 2 115v AC terminals on the very bottom. so i hook the multimeter, one to the ground and one to the first 115v which has the white wire comming off it, and it reads. 0.998
the other 115v which has the black wire comming off of it reads 121.23v

could that be my problem?
 
Last edited:
Nope it sounds like everything's normal, but what you said leads me to believe the board is still possibly fubar'd.

To answer your question regarding the monitor, the monitor is powered by 120v AC BUT it has to be through whats known as an isolation transformer - which is that other transformer you see. From the power cord, usually it goes through a fuse block, a couple switches, then to the power supply (the box with the terminals) and to the transformer (we call it an ISO for short). The box with the terminals provides the 5,12, and sometimes -5v for the board, and the ISO provides 120 volts for the monitor.

When you measure AC, you go across both AC terminals, not from one to ground like you would for DC. The reason why you only saw voltage on one terminal is because with AC you have a "HOT" wire and a "COMMON" wire - the hot wire will show juice and the other will not, but be aware that both are technically hot, and you need to be careful around those. Those terminals are the equivalent of sticking a fork in an outlet.

In your situation though, explaining that you repaired some bad legs, it seems to be your board is probably still bad and thats why you're not getting anything. Depending on what chip it was and where, you can prob get a replacement for cheap instead of fixing the rotted out one you had. Chances are it was a rom chip and those are readily available, especially from some people on here, including a guy named Steph @ HobbyRoms. You just need to clarify where it was and what numbers/codes are on it.
 
Where are you located? This sounds like an excellent opportunity for a visit from a local KLOVer...
 
THanks for all the info! That makes a lot of sense. I understand much more now. That is what i was afraid of. I am checking out HobbyRoms now, if i can get the board working i will just resell it, as i have a replacement comming anyway.
 
well after reseating some chips, now i get still no picture, but i can hear faint constant beep beep beep out of the speaker, it is still blasting static but you can hear the faint beep beep beep.

does that help anyone diagnose?
 
when i put in test mode, power it on holding down 1p start, i get different beeps

more like a beep boop beep boop beep boop
 
Back
Top Bottom