820-3209-a

djdblaster

New member
Hello,

got 820-3209-A here. No chime, fans slowly ramping up to full speed, green and orange light present. All rails present. DCIN board had some junk stuff which was cleared, few probe points on the motherboard also had green-ish stuff on it, cleared with tweezers.

Mouse activity on USB port - Yes.
 

2informaticos

Administrator
Staff member
PRAM reset done?
If still no chime, try other LIO board.
Missing chime and ramping up the fan is more than audio problem on LIO board.
 

2informaticos

Administrator
Staff member
Look at flex connectors and MLB connector under microscope.
Check if all pins are OK.

USB mouse is not 100% perfect indication for activity.
Remove SSD and start with USB OSX.
If the LED of such pendrive flashes, there is surely USB activity.
Then you can start to work on image/backlight part.
 

djdblaster

New member
No Title

Okay, flex cable looks like it had some green-ish stuff. Clean with iso?
 

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djdblaster

New member
Connected external drive through USB, LED on it lights up and stays on. Fans still full speed. Internal SSD is removed. Flex cable cleaned with iso. Checked J4700 with diode mode, nothing seems awkward, yet I don't know the values cause I don't have other board, but everything was pretty much around 0.35-0.4V, except few grounds I guess.
 

2informaticos

Administrator
Staff member
If external drive doesn't flash, there is no activity; board is stuck.
Be sure that drive has bootable OSX, or something else like ASD...
 

djdblaster

New member
I do not understand "if external drive doesn't flash, there is no activity"

Sorry if I haven't written in the first post, but to add to no chime, there is no image on screen too.

The external drive has LED on it and it lights up. I use it for other Macs, works fine.
 

2informaticos

Administrator
Staff member
When booting, that drive should flash one LED, isn't?
Or is an HDD to USB adapter with only one LED for power?
Some adapters have two LEDs; one for power, other for link.
If there is no USB activity, board is stuck, you can't get image, nor backlight.
Should dig more on it...

Use USB port from MLB.
It should work without LIO flex connected.
Only needs the 5 pins power cable from LIO...
 

djdblaster

New member
The external drive is an SSD in the enclosure. It has only one LED. I can try and see on other Macs if it will keep flashing when being used, which I believe it should.

I've used USB from the motherboard, didn't work.
 

2informaticos

Administrator
Staff member
I don't exactly know the behavior of this board.
But I remember several 820-3115 boards which give LCD image without AXG voltage on corresponding coil.
Maybe AXG power supply gets in use only when graphics load increases.
And this 820-3208 is Ivy Bridge too...

So be sure first about USB activity.
You can also try new BIOS.

Look at USB mouse light and see if reacts at PRAM reset.
 

djdblaster

New member
I’ll try that with mouse light and PRAM.
As for BIOS IC, can it be inserted directly to programmer? I don’t think I have an adapter that big.
 

2informaticos

Administrator
Staff member
You messed something there, if had USB activity before.
Do you get correct voltage at L7630 now?
Soldered correct values for R7644/45?
 
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