Recapped SE/30 freezes as soon as sound is played

[d3jsp]

Fully recapped! Boot chime plays fine, but as soon as I try to play any sound from the control panel by selecting an alert sound, the system freezes.
Initially, I thought this could be caused by new caps shorting to another line underneath, but it still freezes after even after removing the 3x 47uf 16V caps.

Does anyone know what could cause this? Can a break in the sound line cause system freezes?

 

[d3jsp]

All traces around the sound chip is fine: https://recapamac.com.au/macintosh-se-30/
But still no sound and freezes

 

[croissantking]

I’m sure I read about someone having exactly the same issue before - iirc it was a broken trace - have a search of the forums.

 

[Bolle]

You'll have to check all the traces going to the ASC. One of them is bad. I think I also had this before and if I remember right it was one of the data bus lines that had a break.

 

[d3jsp]

Very strange, tested all the D line and address lines on UE10 and they seem to be fine

 

[d3jsp]

Checked all the address A and D lines from UG12, UE10 and Swim chip and they are all fine

 

[David Cook]

It's a bit of a leap, but I've had a trace beep showing good continuity when actually:

1. The break occurs just as the trace reaches the pad. The pressure of pushing on pin/pad during testing caused it to temporarily connect. Being really gentle or using an IC clip may reveal the actual break. I discovered my break using a microscope. This caused me to be suspicious and try a gently approach, which proved the trace/pad connection was cracked.

2. The trace has continuity but is degraded such that is fails under high-speed working conditions. Test the resistance; not just continuity.

Again, this is a bit of a leap. But, something to look for if you are desperate.

 

[d3jsp]

Does anyone know where pins 34,37, 36,39 go to from ue10 and how to test them?

 

[d3jsp]

Reflowed and heated the ASC chip and now it no longer crashes but still no sound. Sometimes it will chime when booting but the chime continues and won't stop. Sometimes the speaker will pop non stop but the computer works fine. Sometimes there is no sound at all. Sometimes the speaker pops twice on boot

Can this be a broken ASC chip or Sony chip instead of a broken trace?

 

[croissantking]

Reflowed and heated the ASC chip and now it no longer crashes but still no sound. Sometimes it will chime when booting but the chime continues and won't stop. Sometimes the speaker will pop non stop but the computer works fine. Sometimes there is no sound at all. Sometimes the speaker pops twice on boot

Can this be a broken ASC chip or Sony chip instead of a broken trace?

The fact that reflowing the chip caused a change in behaviour is a useful indicator that you’re already zoned in on the problem area. If you can, I’d completely remove the chip, clean and inspect underneath it, then put it back.

It could be a bad ASC, but it’s much more likely to be a connectivity issue on the PCB.

You could maybe put the ASC in a socket so that it’s easier to test another chip if you get hold of a spare later on.

 

[campbellashe]

I'm having a similar sound issue with a SE30. Had the sound issue before recapping.

Noted before recapping:
a) No boot chime
b) No system sounds
c) Playing sound on Snooper test would freeze machine and would need a power off to restart
d) Playing sound in control panel would freeze machine and would need a power off to restart
e) No sound through head phone jack either

Did recapping with tantalum caps; did have corrosion around C3-C6.
Did use solder mask to protect traces underneath caps
Did bath the board in IPA

After recapping:
ALL the above BUT now noted a crackle of a boot chime on start,
Still similar issues with freezing with sound in Snooper test and control panel.

Examined traces again:
Tested sound related traces using the diagram on Recap a Mac; all connect with continuity
Found some discolored traces around UC12 and UD12
Would you expect the bad traces around UC12 and UD12 to affect sound?
Would you resolder those chips?
Any other suggestions?

 

[d3jsp]

Check all the address and data lines around the asc chip. Mine turned out to be the r/w line

 

[LeSpameur]

Hi, same issue here. Glitched chime and system freezes when playing sound in control panel. Sadly, the R/W line is fine. I noted that the glitch changes slightly when playing it several times. I replaced UE10, UB10 and UB11. I also checked all these traces :
https://recapamac.com.au/macintosh-se-30/

 

[d3jsp]

Did you check all the address lines to the ASC chip? If will act this way if any of them are broken I believe

 

[LeSpameur]

Problem solved, adress line 4 wasn't connected.