M557-G0 no WiFi/Bt no WIFIVendor file?

[howardc64]

Thanks to Diah, got M557-G0 LCD panel buffer board repaired and running ( link ) Next challenge is no WiFi/Bt despite module on the main board and getting 3.3v supply (3.45v measured)

• TV Menu shows Network Access Point option (enet unplugged) but menu can't select that entry
• Service Menu shows many Bt/Wifi info missing
• Vizio app shows no WIFIVendor file

Prior owner used enet and said turned off wifi somehow. It seems system config info for wifi might be missing. Anyone experienced this before?

• Tried countless enet unplug (user manual said need to unplug enet to get to wifi menu), factory reset, system update (with enet) reboot tv, power off/on, dis/reconnect power, DNS off/on (only when enet plugged in).
• After factory reset and initial setup, network setup first shows alert triangle, then performing wifi scan finds nothing
• Internet shows many Vizio users complain of no wifi or frequent disconnects
• Couldn't firmware update via USB. 8GB drive formatted FAT32 (PC/mac has no FAT only), 2 files from Vizio support website, followed their directions, could only get Music, Picture, Video menu when inserting into main board

Anyone encounter this type of issue before?

[Diah]

1- you need to check the areal cable not connect to module chassis... and if the position are correct... for me make no sense when they are crossing each other
2- with Flux clean the soldering and do it again..

after that do hard reset from service menu after you check if wifi enable and the mac listed as it print on the module

[howardc64]

1- you need to check the areal cable not connect to module chassis... and if the position are correct... for me make no sense when they are crossing each other

• Cable all isolated from chassis. Antenna is taped on and insulated. Also made sure cable plugs are not touching wifi/bt model EMI shield
• Crossing over each other at wifi+bt module seems to be from the factory with taped down cable and plastic cover mounts suggesting wasn't opened and moved.

2- with Flux clean the soldering and do it again..
after that do hard reset from service menu after you check if wifi enable and the mac listed as it print on the module

• Fluxed and resoldered the module
• Hot air generally heating the module, communication line SMDs and power source circuit

Unfortunately no difference. I did notice a few things

• Alternating factory reset shows WiFiVendor = QCA (alternate times = No Vendor) which probably = Qualcomm Atheros as they have wifi+bt chips part number starting with QCA. Maybe QCA chip is inside the module. (see attached pic)
• There are 3 places to find enet MAC (System Menu, Service Menu, TV linked Vizio App) and 4 for wifi MAC (System Menu, Service Menu, TV linked Vizio App, Module sticker)
• enet MAC same in all 3 locations
• Wifi MAC is differnet in all 4 locations
• enet + Wifi MAC is same in System Menu

Maybe wifi+bt module is dead. Its location just above the SOC heatsink. TV can't be powered off in ECO mode (will just power back on) so SOC maybe running hotter all the time (80 to close to 100C when SOC is streaming) Vizio smart TVs have been running hot since 2014-15 with a bunch of SOC BGA failures.

ebay used main ~$20 shipped within US.

[Diah]

when i face such part problem related to function, i go straight to read the device specification to be sure if this function enabled

at yours no BT.
over all streaming devices / TV / TV box when they have RJ45 LAN & WiFI WLAN the both MAC of them will be used only to register modules. the real MAC communicated between the device and outside will be ONE. same MAC address what ever we use LAN or WLAN., this MAC written by Key beside other licenses Keys.

SoC reach 100° describe to me the WIFI Module have short / defect. as its connected direct to SoC

so cheap MB i would get it and install it.

[howardc64]

when i face such part problem related to function, i go straight to read the device specification to be sure if this function enabled

at yours no BT.
over all streaming devices / TV / TV box when they have RJ45 LAN & WiFI WLAN the both MAC of them will be used only to register modules. the real MAC communicated between the device and outside will be ONE. same MAC address what ever we use LAN or WLAN., this MAC written by Key beside other licenses Keys.

yes, I also guessed single MAC to outside since TV user manual said WiFi doesn't work if RJ45 is connected.

SoC reach 100° describe to me the WIFI Module have short / defect. as its connected direct to SoC

so cheap MB i would get it and install it.

I forgot to share this TV has USB Debugging feature in service menu ( MENU + 4 + 2 + 1 + 0 ) If turned on, it will produce a system OS log file on the plugged in FAT32 USB. My log ( attached ) shows not finding WiFi and Bt HW as expected ( driver load fails )

Will report back after replacing main. Maybe I'll also try to reflow the SOC on this main to see any effect.

[howardc64]

UPDATE

Replacement main came in. Installed and wifi works (this TV has no BT) and Power off Eco Mode works as well.

Hot air heated the wifi module ( 2-3x ) on the old main with no WIFI HW detected and Power off Eco Mode not working (TV just restart after turning off). WIFI HW is now recognized (see pic) but can't find any SSID. Power off Eco Mode now works. I guess Power off Eco Mode not working was due to the missing WIFI HW somehow and got fixed once WIFI HW showed up. WIFI not finding SSD probably just shows failed WIFI module.

Anyway, this TV is fixed with an extra main that don't do WIFI.

[howardc64]

UPDATE 2

Replacement main has 2 problems

• WIFI HW would be lost on ECO MODE power off and on. Need to unplug/plug power to recovery
• All streaming/smart apps crash and reboot randomly

Back to using original board fixed enough to work perfect everywhere except no WIFI.

These mains must suffer high thermal failure and WIFI too since its soldered onto main and few centimeters above SOC heatsink diagonally with SOC running ~90C when TV on.