Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

faulty gigabyte keyboard

Status
Not open for further replies.

k5j5mto

Newbie level 1
Joined
Jan 9, 2017
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
13
I recently bought a second hand Gigabyte Stealth gaming keyboard, model number GK-FORCE K7 and from time to time some of the keys, like 't', 'backspace' and other keys do not work. The odd thing is when I plug in the keyboard the '4' key is stroking without me doing anything.
I am using Windows 10 but tried the keyboard on different OS's with the same results. Opened the keyboard tested the control board for voltages, faulty parts, traces and connectors with no bad one's found. The main IC is HT82A525R and EEPROM chip is T24C02A.
I am trying to reprogram the EEPROM as soon as I will get the code and see what will happen.
Any suggestions will be much appreciated.Thanks in advance.
 

Take it apart, clean all the contacts and around the IC pins.

Let it dry, test it before re assembly.
 

Is it a membrane keyboard? Remove enough screws, plastic, etc., so you can lift up the membrane. Clean all carbon buttons and contacts. Examine in/ around/ under the 4 key, to see whether it has loose carbon, etc., that makes unwanted contact.

Alcohol is a good solvent to try. Do not use acetone, lacquer thinner, fingernail polish remover.
 

Don't bother with the EPROM, this is a classic 'stuck key' problem.

To explain: the keys don't each have their own connection back to the controller, they are grouped together so that four or five of the keys share a common connection. The principle is called multiplexing or 'matrixing' and it makes the keyboard far easier and cheaper to manufacture. Your problem is the '4' key is stuck closed and that is preventing the signal from the other keys in the same group from being recognized.

Almost certainly as this is a 'gaming' keyboard, the membrane under the '4' key has become permanently stretched so the switch stays closed. Open it up and carefully lift out the three plastic layers of the membrane assembly, there is a top layer, a bottom layer and spacer layer in the middle with holes in it under the key positions. Look carefully and you will see a connection between all the keys that are not working. Normally, when the key is pressed, the top layer (nearest the key cap) is pushed downward through the hole so it touches the bottom layer and makes electrical contact, in your case, the connection isn't breaking when the pressure on the key is released.

Brian.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top