Espgaluda PCB Issues

[luggal]

Hi,

I've been running an Espgaluda PCB on a Sega Blast City for the past few months but I'm having some issues. Here's the PCB. Looks clean to me other than having the battery removed by the previous owner:



The first problem I am experiencing is the following graphical mess when the cabinet is powered on. I am not having problems with other PCB's. Sometimes it seems that if I flip the switch on the pcb a bunch of times it'll eventually display the "for Japan only" message:



Last night the game started randomly freezing during gameplay, then when hitting the credits button. I then started seeing errors - first while playing and then even during the attract mode:




While not exactly the same symptom(s), I found some other posts pointing to the 5v causing the game to reset when adding credits if it was too low. Mine was 5.17v at the edge connector with the game on. First, I dropped it down to 5v even. When I would finally get by the graphical mess I'd just see a black screen in place of the "for Japan only" screen. I bumped it up to 5.25v and there has been no more freezing or errors and I can probably scale that back down a bit. Note that my 12v is 11.90 at the edge connector.

So with the freezing/error problem (temporarily) out of the way, I still get the graphical mess upon startup. Any ideas about what the problem might be? I have a feeling it's something stupid.

[cools]

Snipped for conciseness

I've been running an Espgaluda PCB on a Sega Blast City for the past few months ... Mine was 5.17v at the edge connector with the game on... Any ideas about what the problem might be? I have a feeling it's something stupid.

Why were you running it at 5.17v for months?

[system11]

Could be anything but running it over voltage for so long won't have helped. It's probably a RAM fault.

[luggal]

It's just odd to me that increasing the voltage seems to have corrected the freezing & errors and didn't create more issues.

When I first got the cab I think the 5v was at 5.04. Maybe it got nudged when I pulled a dust bunny out of the access hole to the pot. Maybe I need to be better about busting out the multimeter every time I fire the thing up. I only checked the value with this pcb connected when I started experiencing problems. I don't check my oil or tire pressure every day before I drive either

Yeah, I get it cools - the extra .17v may be the "something stupid"

[matrigs]

Aren't there any voltage regulators on game PCBs? That would be definitely risky.

IMHO the PSU is not giving the PCB enough current.

Raising the voltage raised the current after the voltage regulator (which i asume, is in fact on the PCB) and it started to work, but is probably at the very minimum to do so. Raising it even further pushed the current beyond the needed amount.

I would still NOT recommend to do it this way. Even if there is something regulating the voltage it doesn't necessarily have to be designed for high currents and might heat up a lot / fry

I would definitely try the board on another cab, and check the current at the output stage of the PSU of the cab.

[cools]

Maybe I need to be better about busting out the multimeter every time I fire the thing up... I don't check my oil or tire pressure every day before I drive either

Checking the voltage when you change PCBs is a pretty good idea. You check the tyre pressure when you change them, right?

[matrigs]

Maybe I need to be better about busting out the multimeter every time I fire the thing up... I don't check my oil or tire pressure every day before I drive either

Checking the voltage when you change PCBs is a pretty good idea. You check the tyre pressure when you change them, right?

Well, checking the voltage while having the PCB connected will definitely show if there is any voltage drop.

You also don't measure your tire pressure with your car not standing on the ground.

[ChuChu Flamingo]

The proper way to test the 5V is have it connected and test the furthest IC voltage. Just like how testing it when nothing is connected is wrong since no load, testing it at the jamma connector is not accurate while on either. You just get a ballpark of what goes into your jamma pcb, but not what is actually going through the circuit.

http://wiki.arcadeotaku.com/w/Measuring_Voltages

But yeah in general you don't want to go over 5.10 at jamma connector just to be safe as each pcb jamma key has different resistance, thus it is better to be lower than high.

[luggal]

I tried the pcb on another cab and experience the same issues.

I guess my only other questions at this point are is the board repairable and, if so, any recommendations for who can take a look at it?

[ChuChu Flamingo]

Depends on where you're located. Channelmaniac does good work in the states.

[exidy]

You should check the voltage on a chip on the board.
You can lose a lot of voltage sometimes. Personally I run all my PCBs roughly at 5.1v but running at 5.2v shouldnt cause issues.
I do all the tech work at the 1up & 2up barcades here in Denver and almost all games are set between those voltages.

Jon

[system11]

You should check the voltage on a chip on the board.
You can lose a lot of voltage sometimes. Personally I run all my PCBs roughly at 5.1v but running at 5.2v shouldnt cause issues.
I do all the tech work at the 1up & 2up barcades here in Denver and almost all games are set between those voltages.

Jon

That's mostly old stuff though, a lot of new games get upset past 5.07 or so. Example Gunbird exhibits sparklies over certain graphics.

[exidy]

Interesting. My Egret II is set currently right at 5.1v and ive had no issues.

Jon

[cools]

Garegga/Batrider/Bakraid hardware occasionally hates being run above 4.9v

[brokenhalo]

So with the freezing/error problem (temporarily) out of the way, I still get the graphical mess upon startup. Any ideas about what the problem might be? I have a feeling it's something stupid.

if it's just the first few seconds you flip the board on then it's normal. it should then go into it's boot-up test routine.

[luggal]

Per ChuChu's advice, I sent the board out to channelmaniac. It appears that this board had issues beforehand:

The customs have already been reflowed by someone who did not do a good job. On one side of the chip, the pins aren't set properly on top of the pads and there was conductive solder paste bridging pins on 3 of the customs. Even with all of the RAMs tied to the CPU replaced, the board will not boot.

RIPGaluda