the simpsons
- Thread starter newlands1
- Start date
VectorGlow
Active member
Could be a number of things in the sound section, but the most likely candidate is one of the mask ROMs responsible for the sound samples.
Are all the other sounds ok? There's normally a few different types of sounds on arcade boards:
It's a lot easier doing this whilst you've got the same game running in MAME so you can see how a working board sounds compared to yours. Sometimes there will be gaps in the sound test and without another board or MAME to compare against you don't know if it's a fault or on purpose.
It'll probably be a lot easier to fix if all samples are bust as that focuses on a few particular chips
This thread about an Op Wolf with sound problems is probably worth reading, and this post in particular explains how I did the sound test with Paul & Unit504 - http://www.ukvac.com/forum/forum_posts.asp?TID=328858&PID=751429&title=operation-wolf-sound-issues#751429
The entire thread is here if you want to have a look: http://www.ukvac.com/forum/forum_posts.asp?TID=328858&PN=1&title=operation-wolf-sound-issues
Will try and have a look in MAME over the weekend and see if I can make a sound table like I did for Paul. I'll also burn those ROMs for you
- Samples - for example the speech in Operation Wolf. These are stored as sample data in ROM and then converted back into audio by (commonly) YM3012 serial DACs (DAC = Digital to Analogue Converter, a lot like the insides of a CD player).
- Synthesised tunes - these use the synthesisers built in to the Yamaha and Oki range of OPL chips. They get code uploaded to them which tells them which sound to play, when and for how long. If you remember it, this will sound a lot like chiptunes from the Amiga or C64 or the midi tunes you got on early PC soundcards.
- Discrete sound - not worth worrying about as it's unlikely you'll have any of this on a Konami of that age.
It's a lot easier doing this whilst you've got the same game running in MAME so you can see how a working board sounds compared to yours. Sometimes there will be gaps in the sound test and without another board or MAME to compare against you don't know if it's a fault or on purpose.
It'll probably be a lot easier to fix if all samples are bust as that focuses on a few particular chips
This thread about an Op Wolf with sound problems is probably worth reading, and this post in particular explains how I did the sound test with Paul & Unit504 - http://www.ukvac.com/forum/forum_posts.asp?TID=328858&PID=751429&title=operation-wolf-sound-issues#751429
The entire thread is here if you want to have a look: http://www.ukvac.com/forum/forum_posts.asp?TID=328858&PN=1&title=operation-wolf-sound-issues
Will try and have a look in MAME over the weekend and see if I can make a sound table like I did for Paul. I'll also burn those ROMs for you
Not that I know much but i would pull the sound rom/s and compare to mame, but this is where you start to think, how long am i gonna be into arcade stuff and do i decide to buy a eprom programer, how many slightly bad boards will it take to make you buy one? Even if you buy working boards at some point one or two will go down.
If you have someone down the road who can help it's fine, if not then you have to buy some tools or pay a dude to fix it for you.
If you are passing me i'd check what I could for you
If you have someone down the road who can help it's fine, if not then you have to buy some tools or pay a dude to fix it for you.
If you are passing me i'd check what I could for you
cool thanks for ure tips
but i take it there is a chip on the simpsions pcb will all the samples on it..
so is it a matter of removing it.and re programing it.
or is it harder than that..
what sort eprom programer is the an all round cheap and does the job
but i take it there is a chip on the simpsions pcb will all the samples on it..
so is it a matter of removing it.and re programing it.
or is it harder than that..
what sort eprom programer is the an all round cheap and does the job
VectorGlow
Active member
There are two mask ROMs responsible for the samples, and they are usually soldered onto the board. They also can't be re-programmed, so you would need an EPROM equivalent.
You MAY be lucky and find that the relevant chips are already socketed - any chance of posting a pic of your board?
Having said all that, it may not be one of the mask ROMs at fault (although it probably is).
You MAY be lucky and find that the relevant chips are already socketed - any chance of posting a pic of your board?
Having said all that, it may not be one of the mask ROMs at fault (although it probably is).
hi guys will post a picture of this..
when i was looking at the board one of the smaller chip looked as if the pins were not sitting right
so i removed it .to find a lot of bent legs and leg touching each other
will post a picture of this chip and the pcb
was going to put them right but .dont want to touch them incase am wrong will let u guy tell me if this is right or wrong
when i was looking at the board one of the smaller chip looked as if the pins were not sitting right
so i removed it .to find a lot of bent legs and leg touching each other
will post a picture of this chip and the pcb
was going to put them right but .dont want to touch them incase am wrong will let u guy tell me if this is right or wrong
Bingo!
In the post above where I was talking about how the different sounds are made I mentioned that you'll probably have a YM3012 chip to convert the samples back to audio. If you look just to the left of the socket in your second pic you'll see YM3012 written on the board in white indicating the chip that should be fitted in that position. Hopefully if you turn the chip you photographed over it should be labelled with YM3012 amongst other stuff.
So the reason you've got some sound problem is at least because the seller bodged that chip in place
Do you think you'll be able to straighten the legs? If they've been bent a lot then they may be too fragile. If you do manage to straighten the legs then the chip needs to be inserted with the notch on the chip facing the left (from the point of view of pic2). You can see that all of the chips have a little notch which all point in the same direction, so if you can straighten the legs then put the chip back in, power up and all should be good.
Congrats on your first board fix!
In the post above where I was talking about how the different sounds are made I mentioned that you'll probably have a YM3012 chip to convert the samples back to audio. If you look just to the left of the socket in your second pic you'll see YM3012 written on the board in white indicating the chip that should be fitted in that position. Hopefully if you turn the chip you photographed over it should be labelled with YM3012 amongst other stuff.
So the reason you've got some sound problem is at least because the seller bodged that chip in place
Do you think you'll be able to straighten the legs? If they've been bent a lot then they may be too fragile. If you do manage to straighten the legs then the chip needs to be inserted with the notch on the chip facing the left (from the point of view of pic2). You can see that all of the chips have a little notch which all point in the same direction, so if you can straighten the legs then put the chip back in, power up and all should be good.
Congrats on your first board fix!
VectorGlow
Active member
At least one of the sample ROMs (an EPROM) is socketed.
The chip with the bent legs must be put back into its now empty socket - with care and a pair of tweezers you should be able to straighten the legs without breaking any and put it back in the socket - do take note of the orientation of the notch, so that the notch on the chip (or a small dot in one corner) is at the same end as the notch on the socket (the socket's notched end can be easily identified by not only the notch but there is also 'YM-3012' printed in white on the PCB).
Edit: Tim beat me to it.
VectorGlow2011-09-04 21:27:44
The chip with the bent legs must be put back into its now empty socket - with care and a pair of tweezers you should be able to straighten the legs without breaking any and put it back in the socket - do take note of the orientation of the notch, so that the notch on the chip (or a small dot in one corner) is at the same end as the notch on the socket (the socket's notched end can be easily identified by not only the notch but there is also 'YM-3012' printed in white on the PCB).
Edit: Tim beat me to it.
VectorGlow2011-09-04 21:27:44
Bensonrad said:
The brown EPROM is obviously not original but I wouldn't worry about that at this point. The missing/dead YM3012 will severely impair the sample playback as there is data coming in on pin 4 and nothing to decode it
cliff_poole
Active member
Is it just me or does that chip look like it is doing sit-ups
VectorGlow
Active member
i thought it looked like a dead cockroach ;p
i've had a brief look at the board
sadly the 3012 isn't the cause of the problem. despite being a nightmare to put in (grotty pull with creased legs in a turned pin socket). i didnt think a 3012 would be the problem with half the samples working. in my (limited) experience a fault with the 3012 would mean all samples would be garbled. happy to be corrected there if im wrong.
if i am wrong then the socket could be the problem, its been fitted recently by the looks of things, which suggests an existing problem and attempt to fix, but apparently it was working pre-post according to the seller. (dubious imho)
Ill check continuity on the socket then guess the next stop is the roms. bet its the two remaining mask roms (ugh). the rest have been socketed. think its worth trying a piggyback on the mask roms with an eprom?
i've had a brief look at the board
sadly the 3012 isn't the cause of the problem. despite being a nightmare to put in (grotty pull with creased legs in a turned pin socket). i didnt think a 3012 would be the problem with half the samples working. in my (limited) experience a fault with the 3012 would mean all samples would be garbled. happy to be corrected there if im wrong.
if i am wrong then the socket could be the problem, its been fitted recently by the looks of things, which suggests an existing problem and attempt to fix, but apparently it was working pre-post according to the seller. (dubious imho)
Ill check continuity on the socket then guess the next stop is the roms. bet its the two remaining mask roms (ugh). the rest have been socketed. think its worth trying a piggyback on the mask roms with an eprom?