Category Archives: Hardware

HP Pavilion dv7 Repair – White Screen

Noticed recently the appearance of a white screen at the time of work on the laptop HP Pavilion dv7.
When switching to an external monitor and back by a combination with the Fn key, the image was displayed normally, but after a while the problem appeared again.

The main reason for this phenomenon is likely to be a damaged or poor contact on the plume going to the display.
In my case, its disconnection/connection did not solve the problem, I had to order it on Aliexpress, it’s not expensive there.
Under the battery is written the full name of the laptop model for which you need to order a cable.

After replacing the loop, the problem was solved.

The solution to the error “IP overlaps with VlanXXX. VlanXXX: incorrect IP address assignment”

It was necessary to replace the L3 switch of HP with Cisco once and after a similar switch configuration Cisco noticed an error:

172.16.63.0 overlaps with Vlan111
Vlan121: incorrect IP address assignment

As it turned out the network Vlan111 172.16.0.0/18 was ending at 172.16.63.254, it crossed with Vlan121 172.16.63.0/24.

The HP 5800 switch was configured before that and he did not say anything about it, and Cisco refused to accept the command.

Therefore, since IP addresses were used little in the Vlan111 172.16.0.0/18 network, the problem was solved by reducing the mask to 172.16.0.0/19.

After that, the IP address was successfully registered to the Vlan121 interface.

Done.

Hard reset on Samsung GT-I9505 Galaxy S4

Describe the points for the process of a full reset on the Samsung GT-I9505 Galaxy S4:

1) Turn off the phone

2) Simultaneously press and hold three buttons: “Volume +”, “Home” and “Turn on”

3) After the vibration, release the “Power on” button, when the menu appears, release the rest

4) From the menu, you can move up/down with the volume buttons, so select “wipe data/factory reset”

5) Confirm with the “Power” button

6) Then, in the same way, select “Yes — delete all user data”

7) Wait until the user data is cleared and the settings are reset, when the menu appears, select “reboot system now” to reboot the phone.

Done.

Port isolation on Foxgate switches

For the test, I will configure on the Foxgate S6224-S4, S6224-S2, S6208, and so on.

Connect to the switch through the console or telnet and switch to the configuration mode:

enable
config

Let’s create a group of isolated ports and add ports to it that do not need to see each other (in my case, clients are from 1 to 24):

isolate-port group users
isolate-port group users switchport interface ethernet 1/1-24

The command is the same on all Foxgate switches, but port numbers may differ, for example on S6224-S2 I configured it like this:

isolate-port group users
isolate-port group users switchport interface ethernet 0/0/1-24

After adding the ports to the group they will not see each other, but they will see the ports that are not in the group, I have the 25 port is the uplink on which the Internet comes, because it is not in the group, it sees all the ports, and the ports that the groups see him.

Let’s see the list of ports in the users group:

show isolate-port group users

Leave the configuration mode and save the settings:

exit
write

Connecting SFP-RJ45 Modules to the Cisco 6500

It took a couple of days ago to the Cisco Catalyst 6509-E in which there were modules only with SFP ports to connect a few links with RJ45.

Since RJ45 links are small, it was more economical to use SFP-RJ45 modules, so they were ordered.
I connected them to the ports WS-X6724-SFP, but nothing was displayed in the logs.

Let’s write commands so that Cisco does not disable ports when inserting unsupported modules:

service unsupported-transceiver
no errdisable detect cause sfp-config-mismatch
no errdisable detect cause gbic-invalid

I note that the ports WS-X6724-SFP in my case work only at 1Gb speed, so the link will not naturally rise to 100Mb or 10MB, although the Foxgate SFP-RJ45 modules that we had and support 10/100/1000.

In confirmation of this I checked the commands:

configure t
interface gigabitEthernet 1/1
speed ?

What was the opportunity to specify the speed of the port only in 1000.

See also:
Configure Cisco Catalyst 6509-E

The solution to the error “Service virtual port has existed already”

I noticed once on Huawei MA5683T when I added the service port for ONT the following error:

Failure: Service virtual port has existed already

As reported by the error, the service port is already registered for this ONT.
In my case, there was simply a misprint in ONT ID, it was accidentally indicated by the wrong one, after specifying the correct service port, it was registered.

And if you need to register several service port for one ONT, then see my article – Adding an ONT with trunk port to Huawei SmartAX MA5683T

Adding an ONT with trunk port to Huawei SmartAX MA5683T

Here is an example of adding ONT so that at the output of the ethernet port all VLANs are tagged.
Suppose OLT is configured for my article – Configuring Huawei SmartAX MA5683T through the console.
ONT for the test I’ll take TP-Link GP110 with the configured mode transparent and off DHCP, well, in fact with other single-port ethernet ONT setting is similar.

Continue reading “Adding an ONT with trunk port to Huawei SmartAX MA5683T”