[SOLVED]820-2936-B water damaged USB ports A&B running slow

[jadao]

This board is water damaged at spots like USB A and B circuitry including U4650 U4600. And top side near edges and battery connector. There is no rust, it seems something like coffee...
Keyboard lever connector is gone and Pin 1 PP3V3_S4 and Pin 2 GND of keyboard connector were physically touching each others, plastic melted...

It booted fine with internal HDD but keyboard and trackpad were not working.

Before replacing keyboard connector I just cleaned it and made sure pins 1 and 2 are not touching anymore, removed the short but it was still low 0.7V and found out the zero ohm R7803 on PP3V3_S4 blown up to 500kohm.
Replaced R7803, made sure same diode mode reading compared with other board and board powered up fine with trackpad working fluently but keyboard had some keys not working (arrows, caps lock and some others) shift keys and alt are working.

USB data filter L4610 was blown, I replaced it and now both usb ports are working.

My issues:

-Keyboard is missing some keys no caps lock (no green light on caps key ) no arrows and some others...
-USB A & B are working slow. It boots slowly from external HDD, partitions appear very slowly, ASD EFI take much more time to load but passes all sensors and boot rom tests. This behaviour is with keyboard plugged and unplugged.

Didn't ultrasonic yet the board, I am affraid something wrong with USB portion of PCH. I don't see something else common to USB A and B besides PCH.

Before starting to replace U4650 and U4600 or ultrasonic the board, is there something I can check before? Could keyboard connector cause this slowliness on USB port?

Thanks

 

[dukefawks]

Measure all pins of KBC connector on diode mode. Could be corroded trace. The running slow I have no idea, first see if it will do a PRAM reset and boot into OSX

 

[jadao]

Back to this board. Yes I already did PRAM reset and it booted well into OSX. Tested with other keyboard and all keys worked fine. Sorry my old good testing kbd ended up with a bad flex cable.
Please find attached diode mode readings for kbd connector unplugged, they match the ones on a good board. I still have to replace the broken kbd connector.

Now my concern is slow data transfer on both usb ports...
Not sure what I am doing now but I checked if USB_HUB_SOFT_RESET_L, USB_HUB_RESET_L were not partially messed, they were 3.3V. R2070 PCH_USB_RBIAS measured good also.

Will check for corroded traces and ultrasonic the board, maybe some crap under PCH.

 

[dukefawks]

I would fix all the KBD issues then boot into OSX and see how USB transfer rates are to a USB stick/HDD. I doubt there really is a USB issue. If there really is then check if all USB devices are working. IR/BT/CAM/KBD/TP

 

[jadao]

Ok will do as adviced and will report back.

Just before leaving I noticed some bad looking "through holes?"
They are Z2_CS_L, Z2_MOSI and Z2_SCLK. SPI host to Z2. They are located just under kbd connector and connect to trackpad connector and U5701.

I will check all and report.

 

[jadao]

Keyboard connector replaced and worked ok. Did some transfer tests, compared with known good board and I got same thing on both board:

8.48GB from external usb hdd to internal (sata) hdd 4min08sec vs 4min09sec on known good board
8.48GB from internal (sata) hdd to external usb hdd 5min02sec vs 5min07sec on known good board

I guess I forgot the difference between usb 2 and 3
What trolled me mostly was EFI 3S144. When launched, it took time (almost 1 minute) in ''searching for hardware to run tests...'' but it was exactly same on the other board.

By the way IR/BT/CAM/KBD/TP tested ok and worked fluently.

Maybe normal with this particular board or partition issue. Now board is 100% ok.

I call it ''solved'', you can please close the post.