Ms Pacman rom problem

[vader]

I'm assuming this is definitely a rom problem and sound is wierd also ( really wierd ) what steps are advised beside taking board out and cleaning the contacts and reflowing soldier


Thanks Tim

[eccs19]

Is this the machine you were asking about doing the monitor on?  If it is, I guess it's a safe bet the monitor isn't dead.   

[vader]

Yep, this is the same.  Monitor is working but I'm guessing it's in serious need of a cap kit.  Just gotta figure out the problem with the wierd characters and sound.

Tim

[Thenasty]

this site my help you

http://www.mikesarcade.com/arcade/pacfix.html

[fredster]

You can buy a full set of Roms from Bob roberts.  You can also find people to do it on the rgvac if you need a specific chip.

[RayB]

Did you measure your voltages yet?
Did you check and re-seat chips?
Did you check and clean all connectors?

[vader]

RayB,

I have no clue how to check the voltages, but I will clean and reseat on roms.  Can  I clean sockets with acetone ?  I used to use it at work to clean water damaged circuit boards or is this a bad idea.

Tim

[RayB]

Not sure you should go to that extent, but at least press down on all chips to make sure they are in all the way, and look for broken pins, etc.

As for voltages, a cheap digital multimeter is a must for every game owner ($10-15). Many problems with game boards are related to incorrect voltage. Measuring voltage is easy once you read Randy Fromm's tutorial.

[vader]

I'll read it tonite, I already have the meter....I tend to do some car audio and electrical work around the house.  I email bob about picking up a rom set, even
though I can get the board repaired for about 80 bucks, I'm kinda funny about that
and kind of wanna do it myself

thanks

tim

[fredster]

Yep I agree.  You can't learn if you don't try.

Ever heard of Randy Fromm's arcade School?
He has ways of finding dead chips with a multimeter.

find his tech page on randyfromm.com

[vader]

Man, looking on randy's page and not much luck finding the links ( unless he doesn't want you to  ) anyone got a link

Tim

[vader]

I think I'm just gonna pull the chips and reflow all the socket solder points, hell after 25 yrs, can't hurt.  If that doesn't do anything, I'm gonna place a order with Bob.

Tim

[RayB]

Man, looking on randy's page and not much luck finding the links ( unless he doesn't want you to

[Thenasty]

just remember what Edison said, "He did not fail thousand of times,  but he found how not to make it a thousand times" something along that line anyway......

Best way to learn is from mistakes 
you don't forget those mistakes but you forget how it was done the right way.

[Ken Layton]

On Randy Fromm's site you go to look under GAMING -> Technical Department -> Secret Experimental Technical. Unfortunately it's been down for at least a week that I know of.

[vader]

Yeh...I got that far......after closer inspection of the board, I noticed both CP3 and CP6 on the mainboard are broken.  I guess these are resistors of some sort, they are all over the board.  I'm definitely thinking these are causing a issue.  I have a all green screen now.  If anyone has a idea, please respond.  I will replace those regardless

Tim

[Dav]

I'm assuming this is definitely a rom problem and sound is wierd also ( really wierd ) what steps are advised beside taking board out and cleaning the contacts and reflowing soldier


Thanks Tim

I wouldn't assume a rom problem first.  First thing to do is make sure dip 8 is off because it will cause this.  The syncbus controller and z80 can do that too.  Trying a known good sync bus would be the first thing I'd do.