RB751G-2Hn potentially dead USB port?

[lombmario]

I’m trying to determine whether, in fact, my USB port is dead. The 3G USB dongle worked on the router for almost a year. I upgraded to 6.15, and then it seems the port died. I can use the 3G USB dongle on a computer just fine. The log doesn’t tell me much, and I tried the supout.rif viewer online, but nothing interesting shows up. Here are some lines from the log:

01:04:58 async,ppp,info ppp-out1: initializing... 
01:04:58 async,ppp,info ppp-out1: waiting for packets... 
01:05:20 async,ppp,info ppp-out1: connecting... 
01:05:20 async,ppp,info ppp-out1: terminating... - could not acquire serial port 
01:05:20 async,ppp,info ppp-out1: disconnected

> /port print
Flags: I - inactive 
 #   DEVICE NAME                    CHANNELS USED-BY                  BAUD-RATE
 0 I        usb1                           4                          9600     
>

and on winbox, it says the port is not “inactive” but “invalid” although it might be a minor bug in the description of v6.15.

If I select the port on winbox > System > Ports > [select “usb1”]
and click remove, the port doesn’t come back on a reboot or hardware shutdown. I have to reload the configuration from the file system.

> /system resource usb print
 # DEVICE VENDOR                   NAME                  SPEED                
 0 1:1    Linux 3.3.5 ehci_hcd     RB400 EHCI            480 Mbps             
>

[lombmario]

Hi guys. Can anybody offer some advice or next steps, please?

[jarda]

Try this: remove power. Remove usb dongle. Start router to full boot. Recycle power to another full boot. Remove power again. Put USB dongle back. Start to full boot. And maybe recycle power again. If not helping, netinstall…

[lombmario]

OK since I did all the powercycle stuff, I’ll give netinstall a try. I thought perhaps some supout would show some hardware stats, but it seems a bit thin. I wonder if it’s the solder joints on the USB port need rewetting.

@jarda

Try this: remove power. Remove usb dongle. Start router to full boot. Recycle power to another full boot. Remove power again. Put USB dongle back. Start to full boot. And maybe recycle power again. If not helping, netinstall…

[lombmario]

As I expected, USB still appears dead after netinstall, even wiping everything, configuration and all. After doing that, I ran a supout.rif, and here’s what seems odd.

IRQs
Flags: ro - read-only
 #    IRQ USERS                                    CPU ACTIVE-CPU         COUNT
 0      2 wlan1                                   auto          0         5 256
 1      3 usb1                                    auto          0             0
 2      4 switch0                                 auto          0         1 746
 3     16 beeper                                  auto          0         2 005

SYSTEM
Linux MikroTik 3.3.5 #2 Thu Jun 12 08:15:31 EEST 2014 mips unknown
CPU ACTIVE-CPU         COUNT
 0      2 wlan1                                   auto          0         5 256
 1      3 usb1                                    auto          0             0
 2      4 switch0                                 auto          0         1 746
 3     16 beeper                                  auto          0         2 005

The lines with USB show zero, and I see the same with an RB951Ui-2HnD. I’m not an expert at MT hardware, but a zero is normal, isn’t it? If so, I will re-solder the USB port. The USB dongle doesn’t even show a working light, and it does so on a computer, even without a SIM card.