Ok - I know you did this a long time ago.. But that was very cool... testing a bad eprom in Mame. I'm starting my first restore and just happened across this..
4:20 wat. that's a weird way to explain it. nothing gets sent "through" ram or rom. they have address and data pins, when address is provided they output on data pins what they have at that address location.
how much do you charge to fix these boards i have a galaxian board that is acting up it powers up normally but as soon as you put a credit in and push player one it reboots over and over and over in between it says bad ROM some times it will snap out of it and go into attract mode but it will not alow me to play the game for more than a few seconds
when the game does start the image flips top becomes bottom left becomes right and it flips back and forward from normal to totaly backwards and upsidedown then it reboots again and again saying bad ROM
Please help! Greetings... Galaxian Star Field Issue..The star field that is always running in the backround is NOW moving super fast, raining down the screen! everything else is good! i am a newbie, any advise is appeciated! Where is LFSR function on the board?
@atarilogic The game program is burned into the main ROMs on the PCB. Sounds like the CPU can access the test pattern portion of the program just fine but not the game portion. Simply reseating the ROMs may remedy this. If not.. it could be that you have a bad ROM.. or the circuitry that connects the CPU to the ROMs is messed up and will need to be repaired.
Any idea about a galaxian board with this problem, starfield works good in backround, everything else looks like the matrix code dribbling down in colored lines like ice cream jimmies raining down, game works fine, before I would keep hitting reset and it would work fine for a while
if all video signals fail but the game plays blind . knowing that your monitor as well as harness is fine what part is likely to blame ? video ram at the beging of your diagram or the final chip at the end of the diagram? i have a battle gear 2 racing cab one side works perfect the other side plays blind i swaped pcbs from side to side and the monitor and harness are working fine with the known good pcb installed. this is a hard drive pcb called type-zero by taito . have you or anyone reading this ever had this issue? i have checked and double checked the connections in the board stack as well as the connection to the filter board all seem firmly connected. Thanks Matt
@Orthoshlep Yeah. Blitting is the process of writing a single pixel to he screen. So what these boards do is take a sprite, chop it up into lines, chop that line into pixels and send each pixel (I.E. blit) out to the monitor.
Okay. So, at 11:09 we see the jumbled test pattern. My Galaxian arcade keeps resetting from the test pattern to blank screen. Does that mean when it reaches the next test pattern "phase" that it is hitting a snag and not continuing? I found many of your videos super informative and very logical. Keep it up! Oh, and answer my question if you get the chance. :)
Awesome description of the architecture! Thanks so much for the explanation
Thank you very much! Appreciate you going through the explanation regarding how the board works. Very informative!
Restoring a Galaxian and having this exact issue. Thank you for the lucid explanation.
Ok - I know you did this a long time ago.. But that was very cool... testing a bad eprom in Mame. I'm starting my first restore and just happened across this..
You are the expert! I need to hook up with you and sit down drink some beer and pick your brain for an hour. Nice job on the Galaxian 5☆
4:20 wat. that's a weird way to explain it. nothing gets sent "through" ram or rom. they have address and data pins, when address is provided they output on data pins what they have at that address location.
how much do you charge to fix these boards i have a galaxian board that is acting up it powers up normally but as soon as you put a credit in and push player one it reboots over and over and over in between it says bad ROM some times it will snap out of it and go into attract mode but it will not alow me to play the game for more than a few seconds
when the game does start the image flips top becomes bottom left becomes right and it flips back and forward from normal to totaly backwards and upsidedown then it reboots again and again saying bad ROM
Please help! Greetings... Galaxian Star Field Issue..The star field that is always running in the backround is NOW moving super fast, raining down the screen! everything else is good! i am a newbie, any advise is appeciated! Where is LFSR function on the board?
@atarilogic The game program is burned into the main ROMs on the PCB. Sounds like the CPU can access the test pattern portion of the program just fine but not the game portion. Simply reseating the ROMs may remedy this. If not.. it could be that you have a bad ROM.. or the circuitry that connects the CPU to the ROMs is messed up and will need to be repaired.
Any idea about a galaxian board with this problem, starfield works good in backround, everything else looks like the matrix code dribbling down in colored lines like ice cream jimmies raining down, game works fine, before I would keep hitting reset and it would work fine for a while
if all video signals fail but the game plays blind . knowing that your monitor as well as harness is fine what part is likely to blame ? video ram at the beging of your diagram or the final chip at the end of the diagram? i have a battle gear 2 racing cab one side works perfect the other side plays blind i swaped pcbs from side to side and the monitor and harness are working fine with the known good pcb installed. this is a hard drive pcb called type-zero by taito . have you or anyone reading this ever had this issue? i have checked and double checked the connections in the board stack as well as the connection to the filter board all seem firmly connected. Thanks Matt
@Orthoshlep Yeah. Blitting is the process of writing a single pixel to he screen. So what these boards do is take a sprite, chop it up into lines, chop that line into pixels and send each pixel (I.E. blit) out to the monitor.
Very cool video! It's very impressive how you can figure out the problem and step by step solve it!
Okay. So, at 11:09 we see the jumbled test pattern. My Galaxian arcade keeps resetting from the test pattern to blank screen. Does that mean when it reaches the next test pattern "phase" that it is hitting a snag and not continuing? I found many of your videos super informative and very logical. Keep it up! Oh, and answer my question if you get the chance. :)
When I boot up my galaxians pcb board it shows doted garbage on the screen its up and running but it is some type of video error
I have a galaxian arcade game and the screen is dim and bounces around could that be a bad PCB or something esle ?
Where do you find all the diagrams/schematics?
I'll be damned...I was sure it was one of the RAM. Nice job!
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Enjoyed this video! thanks for sharing!
Nice job!