No Chime at Startup

[wbennett102]

I recently replaced an 820-2279-A logic board in my sister's Early 2008 13" MacBook Model A1181. It seems to be working fine but from past experience no chime usually means the failure of a low level hardware test and usually means the machine will not start up.

Does anyone know if this test is the same Power On Startup Test (POST) in the "About This MAC>System Report>Diagnostics"? When I navigate to there the status it always says "Passed" with the associated Date/Time of the most recent reboot.

I've checked some obvious candidates:
- Internal sound drivers/speakers working (although volume seems a bit low)
- Earbuds working
- Sound level not set to 0 at shutdown
- Reset the SMC
- Reset NVRAM/PRAM with (Cmd-Opt-P-R) startup (Note: No chimes here either but the screen flashes and the NVRAM appears to have been reset
- Tried command line:sudo nvram -d SystemAudioVolume

Is it possible that this replacement board might have a bad port I'm not using? If yes, why would POST say Passed?

I am able connect to the internet directly with Ethernet cable or wireless with the airport card and can not see any issues.

Any ideas about what happened to the chime would be appreciated.

Additional MacBook Information
Model Identifier: 4,1
Processor: Inter Core 2 Dual 2.4 GHz
Boot Rom Version: MB41.00C1.800
SMC Version: 1.31f1

 

[Cory Cooper]

Hello and welcome.

Technically, that is not a user-serviceable part. Yes, that should be the same POST process. It only needs to see that the processor and RAM are functioning to pass.

-Are you getting any pattern of beeps, or just no startup chime?
-Does the sleep indicator light blink in a pattern?

It sound like the speaker cable connector is not seated properly, or was damaged when reassembling the MacBook. If all the other things you stated are normal, POST shows as passed, and the MacBook is functioning normally otherwise, I would ignore it, or check the speaker/cable.

C

 

[wbennett102]

Thanks for your response.

I will recheck to speaker connectors. I actually pulled the wires out of the blue-tooth connector while it was still attached to the old board before I realized the connectors lift up and off the logic board.

To answer your questions: 1) I don't hear any sounds at startup. 2) I'm not familiar with the "sleep indicator light'. Where is it and what can it indicate?

As an aside: Do you think there is any information in verbose mode? It comes well after the chime should sound? Also, is there any way to "capture" verbose text? It scrolls quickly off the top of the screen.

Bill

 

[Cory Cooper]

The sleep light is on the front right (edge) corner - white light. It pulses when the MacBook is sleeping. If there are hardware problems, such as bad RAM, and you can't hear the beeps, it will blink in a pattern during startup.

Mac computers: Sleep Indicator Light behavior

As for info from Verbose Mode, in Terminal, you can type:

sudo dmesg | more

The is the pipe character between dmesg and more - hold Shift and press the backslash key. That should list all messages since startup - look towards the top. The more command allows you to view them page by page.

C

 

[wbennett102]

Thanks for this valuable information. I was not aware this machine had a sleep indicator. It does but it does not seem to work which probably ties into my chime problem. I can put the machine into sleep mode but the sleep light stays off. Also at startup it is supposed to come on briefly until the display turns on but never comes on at all. Maybe I missed connection to the logic board. Do you know where it connects to the board? Or maybe a better question would be is there a source for more detailed documentation for MacBooks like schematics/wiring diagrams. Thanks again you have already been a big help to me.

Bill

 

[Cory Cooper]

MacBook Core 2 Duo - iFixit
https://www.ifixit.com/Device/MacBook_Core_2_Duo

C

 

[wbennett102]

Ok I was using an iFixit repair guide for slightly different MacBook. Your reference is closer to this Early 2008 model though not exactly. It mentions some connectors need to be pried up to removed. My instructions didn't have that and it references some 2009 MacBooks that use the same 2179 board and notes the differences.

This more accurate guide is a big help. However, neither set of instructions mentions the SIL. I will go back later and start to disassemble to trace the wiring. At least I'm not at the dead end I thought I was at.

Bill

 

[wbennett102]

OK
Good news. It looked like one of the speaker connections was slightly ajar. Removed it reseated it and SUCCESS - THE CHIME IS BACK. Everything is fine now. (Except SIL which I am not worried about

Bad news. In buttoning everything back together I pinched the upper case ribbon cable that connects it to the mother board. New cables available from several on-line sources. No big deal - BUT when disconnecting the upper case connection I ripped the socket off the board. WHAT A SETBACK!!! Now I need an upper case. I am so upset with myself. Nothing hurts like these self-inflicted wounds. In this case I have worked with this style connector before and saw the iFit warning about prying on the wrong side. I think I had the board upside down from the diagram but I should have recognized it. Maybe your know of some source for macbook parts.

Anyway thanks for all your help.

Bill

 

[Cory Cooper]

No worries...glad the sound is working, but sorry to hear of the new issues. I don't have any good sources for those kind of parts. Maybe just a quick Internet search.

Good luck,

C

 

[wbennett102]

Actually I have a replacement upper case with ribbon cable coming from Apple Outlet in Ohio. They sold me the logic board which worked out well. They just happened to have one of these units that match my macbook model. Their prices are quite reasonable. I will post a follow-up when i get it installed and back up.(fingers crossed).

Bill

 

[wbennett102]

MacBook repaired and returned to my sister. Replacement keyboard arrived quickly. I did get a scare when when the replacement keyboard did not fix the problem . Could the problem actually be the replacement motherboard? After almost a week of diagnosis I able to determine something was shorting somewhere as I pressed the uppercase down on the lower case. After I applied some thin tape to the ribbon cable and proceeded to button things up it has been working fine.