Any Tricks for Fixing Laptop Keyboards?

[mike]

Dell Inspiron 1501
Keyboard has 11 keys that don't work.
Spread all over the keyboard in small groups.
I'm assuming it's a standard X-Y matrix with an open
trace somewhere.
Haven't found any hints that there's a standard for
such things.

If I had five hands, I could probe the thing in place.
Not much chance of connecting the cable otherwise.

Been thinking about measuring capacitance at each line
and watching it change as I poke a key.
Or injecting RF and tracing it around with a current probe
on a spectrum analyzer.
I once fixed a matrix by hitting it with a stun gun and
looking for the arc.

Any clever ways to figure out where the line break might be?

Yes, I know I can buy a used keyboard for $8, but that's 8x
what the laptop is worth, and I wouldn't have nearly as much fun.

Thanks, mike

 

[N_Cook]

On 14/09/2014 09:35, mike wrote:

Dell Inspiron 1501
Keyboard has 11 keys that don't work.
Spread all over the keyboard in small groups.
I'm assuming it's a standard X-Y matrix with an open
trace somewhere.
Haven't found any hints that there's a standard for
such things.

If I had five hands, I could probe the thing in place.
Not much chance of connecting the cable otherwise.

Been thinking about measuring capacitance at each line
and watching it change as I poke a key.
Or injecting RF and tracing it around with a current probe
on a spectrum analyzer.
I once fixed a matrix by hitting it with a stun gun and
looking for the arc.

Any clever ways to figure out where the line break might be?

Yes, I know I can buy a used keyboard for $8, but that's 8x
what the laptop is worth, and I wouldn't have nearly as much fun.

Thanks, mike

The last regular x-y matrix of keys I saw was perhaps 20 years ago, ever
since some apparently random walk pattern.
All 11 keys probably on one trace. Go on, you know you want to, try your
stun-gun kill-or-cure approach again

 

mike <ham789@netzero.net> wrote:

Dell Inspiron 1501
Keyboard has 11 keys that don't work.

Have you tried unplugging it and plugging it back in? The keyboard, I
mean.

If there's a hard plastic connector on the end of the flex cable,
sometimes it loosens itself as the laptop is knocked around. Or, if
it's the kind where the flex goes right into the motherboard connector,
sometimes gunk spilled into the keyboard gets into the connector.

Matt Roberds

 

[chuck]

On Sun, 14 Sep 2014 01:35:36 -0700, mike <ham789@netzero.net> wrote:

Dell Inspiron 1501
Keyboard has 11 keys that don't work.
Spread all over the keyboard in small groups.
I'm assuming it's a standard X-Y matrix with an open
trace somewhere.
Haven't found any hints that there's a standard for
such things.

If I had five hands, I could probe the thing in place.
Not much chance of connecting the cable otherwise.

Been thinking about measuring capacitance at each line
and watching it change as I poke a key.
Or injecting RF and tracing it around with a current probe
on a spectrum analyzer.
I once fixed a matrix by hitting it with a stun gun and
looking for the arc.

Any clever ways to figure out where the line break might be?

Yes, I know I can buy a used keyboard for $8, but that's 8x
what the laptop is worth, and I wouldn't have nearly as much fun.

Thanks, mike

I haven't had any luck trying to repair that keyboard. I would get a
new one. I think they were around $16.00 shipped on EBay.