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geekhack Community => Keyboards => Topic started by: hifiguy99 on Wed, 11 November 2020, 19:07:56

Title: Reuse Model F XT PCB or Replace?
Post by: hifiguy99 on Wed, 11 November 2020, 19:07:56

Hi all,

I am in the process of restoring two model F XTs. Both are type 2 and had water damage to both of them. I am wondering if I should reuse the PCBs.

[attach=1]
[attach=3]

The top one with gold traces worked well. All keys worked and only sometimes it would glitch out using a Soarers converter before I took it apart.

Extent of damage:
[attach=2]
[attach=4]

The bottom one with dark green traces would spam random keys and lock up frequently:
[attach=5]

However the springs were rusty in the dark green traces one and the flipper would stick commonly causing some of the key spams. I am wondering if I can reuse any of this or I shouldn't bother.
Does anyone know where can I source these PCBs? Additionally, who here knows the difference from the gold trace and dark green trace one?

I am also wondering if these are repairable at all? I have some Deoxit D5 I can soak these PCBs in. I tried for a few minutes already before wiping with minimal results though. Any other suggestions in fixing? Could I reflow it with solder or lay some wire? These boards are coated with something so idk how feasible is this.

Thanks!


EDIT: Scrapping the surface reveals copper underneath, so maybe it's safe to reuse as it's just surface coat discoloration/oxidation? Any input on this?

Title: Re: Reuse Model F XT PCB or Replace?
Post by: hifiguy99 on Thu, 12 November 2020, 13:37:21

Well I should've done this from the beginning - it seems like the one with gold traces seems to spam randomly when I plug it in. I thought that one was the better of the two. I held it up in the air by the wire to see if it would still register phantom touches without touching anything and it does.
The one with dark green traces I can type on by shorting the capacitive pads just fine with my finger or the flipper and no phantom touches.

If anyone wants a broken XT PCB please contact me 

Title: Re: Reuse Model F XT PCB or Replace?
Post by: hifiguy99 on Wed, 25 November 2020, 11:00:25

Quote from: hifiguy99 on Thu, 12 November 2020, 13:37:21

Well I should've done this from the beginning - it seems like the one with gold traces seems to spam randomly when I plug it in. I thought that one was the better of the two. I held it up in the air by the wire to see if it would still register phantom touches without touching anything and it does.
The one with dark green traces I can type on by shorting the capacitive pads just fine with my finger or the flipper and no phantom touches.

If anyone wants a broken XT PCB please contact me

Actually I have found out that the PCB works fine. It was a grounding issue all this time. As I don't have enough posts, so I can't list this on the marketplace here, please PM me if interested.

Title: Re: Reuse Model F XT PCB or Replace?
Post by: yui on Fri, 27 November 2020, 02:00:21

as far as i know the as long as the liquid did not go up to the chips and that all traces are at least mostly intact it should still work, and the reason why one is gold and the other green is the finish, different color of solder resist on top (yellow-ish transparent vs green), and if you still care for rebuilding one Eclipse sells springs and hammers for model F along with his new model F77 and F66.
and yeah Fs are very sensitive to grounding issues.
to me if when you scrape you get copper just scrape the oxide and reseal it with a solder resist pen or nail varnish (pretty much the same thing, just the nail stuff is much cheaper and have many more color options :)) to protect against further oxidation. although you will need a fairly thin layer.

Title: Re: Reuse Model F XT PCB or Replace?
Post by: hifiguy99 on Sat, 28 November 2020, 00:34:52

Yup! I actually kept in close contact with him while repairing my keyboards. I do have some conformal coating I can apply. Thanks for the suggestion!

Here is the result:
(https://i.imgur.com/Ae6QRvu.jpg)

Title: Re: Reuse Model F XT PCB or Replace?
Post by: tp4tissue on Sat, 28 November 2020, 08:32:19

you can blow the chips with an electric blower or electric leafblower.

Title: Re: Reuse Model F XT PCB or Replace?
Post by: yui on Mon, 30 November 2020, 05:50:08

Quote from: hifiguy99 on Sat, 28 November 2020, 00:34:52

Yup! I actually kept in close contact with him while repairing my keyboards. I do have some conformal coating I can apply. Thanks for the suggestion!

Here is the result:

Show Image

(https://i.imgur.com/Ae6QRvu.jpg)

nice, can't even guess there was damage.