SE/30 connection between ASC and sound chips

[CharlieFrown]

Hi, I have a SE/30 saved from major caps leakage, apart from recap had to repair some chips and vias to restore video. Still there's a sound issue, you cant hear it at all and whenever the programs call the sound it crashes. For example in Disk Copy it happens when I keep "Confirm before copying" option on (it should beep on normal Mac), it's fine when it's disabled. 

So what seems obvious to me is check the connection between ASC and Sony sound chips. I have a schematic for the SE/30 logicboard, but the problem is I can't really figure out orientation of the pins on ASC and Sony sound chips. How can you tell which one is pin 1 and the others ?

 

[mraroid]

Hi...  others here will probably have a better answer tha this, but....

What I have done in the past is Google the chip ID printed on the chip and find the data sheet for it.  The data sheet will have the pin out of the chip plus all other good information.  On issue is that if a company made a in house chip that was only used in its stuff, than you often can not find any information about it.  

Where did you find a schematic for your SE/30?  I am looking for one.

Mraroid

 

[Bolle]

This sounds more like a problem with the connection between bus and ASC.

You won't find any data sheet for those custom Apple parts, but why not grab the SE/30 schematics and just check every connection according to them?

 

[Trash80toHP_Mini]

I have a schematic for the SE/30 logicboard, but the problem is I can't really figure out orientation of the pins on ASC and Sony sound chips. How can you tell which one is pin 1 and the others ? 

There are conventions for pinouts of all the different IC packages. There will be a marker, divot, cut corner, beveled edge or the like used for identifying pin one.

 

[vilasaliv]

Is there anything like this bare Logic for amiga to our corroded se30?

http://wordpress.hertell.nu/?p=587

 

[CharlieFrown]

I found schematic here:

https://museo.freaknet.org/gallery/apple/stuff/mac/andreas.kann/schemat.html

 

[techknight]

This is common. 

There is a control line that likes to go open between the ASC and the GLU. Check that first. Then check the address/data bus lines afterwords. This line gets affected by the same cap that affects UE8. 

 

[mraroid]

I found schematic here:

https://museo.freaknet.org/gallery/apple/stuff/mac/andreas.kann/schemat.html

Thank you for the link to the schematics CharlieFrown, and happy holidays to you.

mraroid