(347) 552-2258 [email protected]

820-00923 No audio device. Otherwise fine.

bjf

bjf

Member
This board started working after replacing the sense resistors R7061 and R7062. The only issue I'm having now is that it registers no audio device. I've scoured everything on the board I can think of. Any thoughts where to look next? I attached pre-ultrasonic cleaning pictures.
 

Attachments

  • photo1844.jpg
    photo1844.jpg
    4.9 MB · Views: 0
  • photo1845.jpg
    photo1845.jpg
    5.3 MB · Views: 0
  • photo1846.jpg
    photo1846.jpg
    5.1 MB · Views: 0
  • photo1847.jpg
    photo1847.jpg
    4.9 MB · Views: 0
D

dukefawks

Administrator
HDA data lines have resistors in them to U6200. I don't think I even have the schematic/BV for this board. Power to U6200 is also suspect of course.
 
bjf

bjf

Member
The diode measurement on the HDA lines was around .530 instead of .730. I pulled a few of the HDA resistors to isolate the cause of the lower voltage drop to ground and it ends up it's on the CPU side. Does that mean I'm done? HDA_BIT_CLK_R, HDA_SDOUT_R, HDA_SYNC_R and HDA_RST_R_L are all around .530 instead of .730 on the CPU side of the resistors.
 
C

cobragfox

Member
Hello don't know if this will help, on a 820-3662, had the same issue where it doesn't register any audio device. it ended up being the audio codec chip. You may want to try looking around that area, make sure its getting all it's power.
 
D

dukefawks

Administrator
.530 seems fine to me, why do you want to see .730 there? The only thing needed are those data lines and power to the codec for the system to see the chip. If you can find all the resistors you can pull them and check if both sides have a diode mode reading confirming traces are good. I assume you checked power to the codec?
 
bjf

bjf

Member
I'm not really sure which chip is the codec chip but U6200 and U6300 have 1.8V on C6203 and C6301. The reason I was looking for something closer to .730 on the CPU side of the resistors is because that's what I'm measuring on a good board.
 
D

dukefawks

Administrator
U6200 is the codec. If that one has power and all HDA lines have at least a diode mode reading on both sides of the resistor it should recognize the chip in OSX.

See if it really is no audio device in OSX or no output device.
 
bjf

bjf

Member
In the System Report under Audio it says Devices: with nothing after it. Intel High Definition Audio has only Audio ID: 0 under it. In the Output section in Sound in System Preferences is says No output devices found. Input says No input devices found. It looks like U6200 is not being recognized.
 
You must log in or register to reply here.
Top