A1466 820-00165-A

[hgoncalves]

Hi,

I have an A1466 820-00165-A that has no image on the external monitor, but everything else is working well. On the board everithing seems ok, and I have no idea from where to start the diagnose. Can you help?

 

[2informaticos]

Any history available?
Clean Thunderbolt connector as first step.

 

[hgoncalves]

Hi.
No history. The client says that it just stop working, and there is no signs of oxidation on the board.
Already cleaned the connector without success.

 

[2informaticos]

Check DP_PWR at J3200.
Also check for reaction at HOT_PLUG_DETECT, when connect/disconnect a Thunderbolt device.

Try another Thunderbolt adapter too, just in case.

 

[hgoncalves]

DP_PWR (on R3201) has 3.3v
HOT_PLUG_DETECT (on C3202) has a voltage drop when conected an dvi adapter (from 0.156 to 0.08)

 

[2informaticos]

That is irrelevant, the signal must go high.
Try changing U3220; be sure to have good solders and traces.

 

[hgoncalves]

Some changes.
After replacing U3200, i get an image on external monitor, but with very, very bad quality (green image with several large horizontal stripes). Can it be a bad U3200, or bad solders?

 

[2informaticos]

U3220 manages the data lines for Thunderbolt port.

 

[hgoncalves]

It worked. It were bad solders on the new U3220.
Thank you so much.
Regards,