SE with no sound

[falen5]

Hello again peoples.

Took down one of my SE's.

Turned it on and no sound. As far as I know the SE's sound system is all on the logic board and not the analog. Nothing from the headphones jack either.

Has anyone ever had to replace the caps on an SE yet. I havnt!. Then again these machines, like myself, are not getting any younger.

Perfect 5 and 12 volts present on hard drive.

 

[falen5]

anyone?? Anyone every have to change the radial caps on an se logic board for no sound ??

 

[bibilit]

No, SEs are bulletproof on this side.
 

 

[jupo]

Ditto. Plenty of SE/30 issues, Classic issues, LCs, etc. No issues with SEs so far.

 

[falen5]

Thats what i Thought

Ive never had to recap one of them. I checked a few of the caps and there values are right where they are supposed to be.

did find this - there are 2 of the 4 ram slots populated - banks 3 and 4

when i relocated them to 1 and 2 it wont boot at all

wondering if i have dodgy memory modules - would they mess with the sound!!

taking down another se - this is driving me nuts

 

[falen5]

Tried another working se.

Swapped good logic board into machine - sound good. Sp speaker is working.

Tried bad board in good se - no sound. So its not the analog board either.

Still no sound.

Problem is definatley on the se's logic board.

Either I have leaking caps on the se logic board somewhere, or a dead sound chip.

When i turn on the machine, i get a screen of random crap for about 10 to 15 seconds, then it resets itself and boots normally. That is not a normal boot for an se.

Get to the desktop. Everything is good. Just no sound.

Tried the headphones - no sound.

Have never had this problem on an SE before. I have snipped 2 of the caps on one side  to test them - they were in spec.

Only other thing now is to test them all

 

[360alaska]

Based on these symptoms I'd suggest swapping the ram. and also, be sure to properly configure the SE board using the resistors or the jumper.

http://lowendmac.com/2016/memory-upgrades-mac-se/

 

[falen5]

Already tried it Alaska.

No change.

will swap the rams with the working SE - might as well swap the roms as well - this has me stumped.

I searched the threads , for a long time, cant find anyone else with no sound on an SE.

Board is in excelent condition. I removed the battery holder to have a look under - looks clean. No acid leaks, no electrolite leaks

possible dead soundchip? - dont think ive heard of that on and SE before either !!

I dont like this hobby anymore !!!!!!!! hahahah

 

[360alaska]

I've never seen a bad sound chip on a se, but I suppose it is possible that the speaker could short and take it out. A schematic for the sound portion of the SE board has not been released to the community as far as I know, here is the plus schematic:

 

[falen5]

thanks Alaska.

looking at that diagram - if pins 2 ans 3 of the audio jack are shorting then the speaker would be off ?

looking again - it says microphone jack - i thought that was a headphones jack

have swapped all four rams from good se - now have 4 meg of ram. That link you shared in ur previous post was very helpful

I didnt know that to get to 2 or 4 meg you actually remove the jumper. I was moving it from the 1 meg position to the 2/4meg position

ive thought half my machines have bad rams - for Years !!!

any point in switching the roms ? machine boots fine , runs fine , just no sound.

Just discovered - the reset and interupt switch's dont do anything. And when you turn the machine on the screen is filled with junk - long pause - then it resets itself, checks its ram , and then boots. That is not the usual sequence.

Something going on with the reset and the reset during power up. Maybey sound issue is related

 

[360alaska]

It says "miniphone", that is a mini-phone connector. Looks like pins 1 and 2 should be connected when headphones are not plugged in. If 2 and 3 are connected, then you're shorting you audio out to ground.

 

[falen5]

just booted to desktop again. Pressed reset. a full 10 seconds pass, mouse frozen, nothing happening, then it resets

Thats how it boots from powerup. screen of junk, 10 seconds pass , then reset, memory check then boot.

Thats not correct. It is supposed to reset as soon as you press the button. Or was that classics!!!

Dam its hard to remember stuff from model to model.

will check the jack pins now.

 

[falen5]

pins 1 and 2 closed as they should be.

looking at these little tantulam caps - they either work or explode right ? have looked a all of them with magnafying glass. I just cant see ant signs of damage anywhere. The board looks brand new!!

checked both reset and interupt switches - they look good.

Problem is 100% on the board - have tested other , good board in machine and sound perfect. Its not the analog board, the speaker or the jack connector.

might as well swap the roms now. I dont know what else to try.

swapped the roms - no change

thought i saw a crack in solder of pin on sony sound chip - reflowed all pins - still no sound.

i get the static click when i power on the machine , like all macs, thats followed by the beep....... but no beep from this.

will try the heat test - power it up for 10 mins and feel the chips for high temps.

ah feck it - enough for tonight Beer time.

 

[falen5]

I have a dead se/30 board (in 2 halfs, thats how much that one upset me!!) - it has the same sony sound chip as the SE board.

will swap the sound chip - only thing left to try

 

[benlong200]

The suspense is killing me! Did you ever find the problem? I also have an SE that works fine, but no sound.

 

[antongale]

I have this same problem.

 

[antongale]

I've been troubleshooting my no sound issue for a bit and I believe the issue is in the BBU.  The Sony PWM DAC 3430045B chip is not receiving any signal on pin 16 when attempting to play audio.  The voltage at pin 16 is always @ 5V.  I have lifted the input pin of the 3430045B and there is still a constant 5V signal.

The schematics are lacking, so I could be barking up the wrong tree.  I do not believe there are any other components between pin 46 of the BBU and pin 16 of the DAC.

As a side note the volume setting does work, but I'd expect that as the 3-bit control signals come from a different source.

Does anyone have any insight?