VPCF21Z1E strange keyboard problems

[lefos]

Hello,

Strange problem here..On this laptop there are randomly pressed buttons. Firstly seemed to be from the keyboard but even if it is disconnected from the board and you can touch the keyboard's connector the laptop has the same problem! With external keyboard of course it works ok .
I have already checked with a new keyboard with no result.Its motherboard is MBX-243.
There is no liquid damage and the laptop is in perfect condition.
I have already reflowed the HM65 chipset without any positive result.
The problem might be from the winbond chip but I would like a second opinion here.

Thanks for your time.

[whaldsz]

Re: VPCF21Z1E strange keyboard problems

How about cleaning the board first with IPA, Trace the lines that go from keyboard connector to the winbond chip before you replace this chip?

[lefos]

Re: VPCF21Z1E strange keyboard problems

Thank you for your kind reply. I have already cleaned the board and the connector with isopropyl alcohol but nothing changed. I had to give the laptop back to its owner because he needed it. I tried to search for the diagram but had no luck. Can somebody help me with that?

[lefos]

Re: VPCF21Z1E strange keyboard problems

Hello,
Just wanted to inform that my customer brought back and left it to me for further check. After changing the winbond ic it works. Might help somebody in the future.

[spidey]

Re: VPCF21Z1E strange keyboard problems

change ec.

[lefos]

Re: VPCF21Z1E strange keyboard problems

Ec?

[orientalsniper]

Re: VPCF21Z1E strange keyboard problems

Ec?

He meant the EC chip, looks almost like the BIOS but with lesser storage. When you said Winbond chip, did you mean the BIOS chip?

[lefos]

Re: VPCF21Z1E strange keyboard problems

No I didn't meant the bios chip. It is the npce791la0dx winbond.

[orientalsniper]

Re: VPCF21Z1E strange keyboard problems

Is that the KBC? I had a similar problem in a Toshiba Mini and I changed the board. Didn't even check the Nuvoton chip

[lefos]

Re: VPCF21Z1E strange keyboard problems

Yes the same happened to me! Ordered keyboard but had the same issue. The laptop `types` characters even with keyboard`s flexible cable disconnected. Anyway hope I could help somebody someday on this one.

[spidey]

Re: VPCF21Z1E strange keyboard problems

EC = Embedded Controller = KBC = Keyboard Controller Chip