DZ60 pcb

mannoso

04 Oct 2019, 05:21

Hello. I have recently purchased a fully assembled DZ60, and I decided to desolder the switches in order to swap the springs with lighter ones. The problem is that 4 switches now are no longer working, those that on the PCB are labeled as esc, 1, 2, 3 and 4. Can you please help me understand what went wrong, and to understand how can I fix it? Here's a picture of the PCB.
_20191004_051946.JPG
_20191004_051946.JPG (1.17 MiB) Viewed 398 times
Sorry for the quality but I only have my smartphone's camera.
Thanks.

andrewjoy

04 Oct 2019, 14:50

Keyboards work in a matrix So a fault on one switch can cause problems for other in that part of the matrix.

Chances are that one of the pads that you solder the pins from the switch into has been lifted this can happen on lower quality PCBs when using a soldering iron with poor temperature control. Some of your joints also look dry.

You need to inspect each solder point and make sure that its soldered correctly. A few of the solder joints on your photo look dry, this means they are not connected properly. Tab 5 4 3 2 q e look suspect, and 5 looks like the pad may have lifted.

Re solder all but 5 for now, they should look like the pin on the right of number 1 ( the one next to the USB port) thats a good joint.

The best way to solder is to heat up the pin and the pad and add the solder to the pin and pad not the iron. Once you added the solder wait a moment ( just under 1 second) for the solder to flow, then remove the iron. Dont move the iron around when its in contact with the pad and only leave it on there for long enough to heat the joint.

It looks like the solder you have used had flux in it ( thats good ) but there is now used flux on the board. Before you re solder any joint use a cotton bud ( or q-tip in US) with some rubbing alcohol and try to clean some of that off. Used flux is just contamination on your board that will make soldering harder.

Try to get 60/40 leaded solder if you can, it much easier for inexperienced users as it flows much better and at a lower temp. ( honestly everyone should use leadded, the joints are less likely to fail due to mechanical stress )

Once you have done that can you take a closer photo of that number 5 key , the pad looks damaged! Dont worry we can fix that , but i need to see it closer up.

Findecanor

04 Oct 2019, 15:49

andrewjoy wrote:
04 Oct 2019, 14:50
Try to get 60/40 leaded solder if you can, it much easier for inexperienced users as it flows much better and at a lower temp. ( honestly everyone should use leadded, the joints are less likely to fail due to mechanical stress )
Unfortunately, there is recent EU regulation (March 2018) that restricts sale of leaded solder to hobbyists.
You would have to buy it through a registered business or order it from abroad and hope that it does not get caught in customs. .. or find a seller that just doesn't care.

mannoso

05 Oct 2019, 23:39

andrewjoy wrote:
04 Oct 2019, 14:50
Keyboards work in a matrix So a fault on one switch can cause problems for other in that part of the matrix.

Chances are that one of the pads that you solder the pins from the switch into has been lifted this can happen on lower quality PCBs when using a soldering iron with poor temperature control. Some of your joints also look dry.

You need to inspect each solder point and make sure that its soldered correctly. A few of the solder joints on your photo look dry, this means they are not connected properly. Tab 5 4 3 2 q e look suspect, and 5 looks like the pad may have lifted.

Re solder all but 5 for now, they should look like the pin on the right of number 1 ( the one next to the USB port) thats a good joint.

The best way to solder is to heat up the pin and the pad and add the solder to the pin and pad not the iron. Once you added the solder wait a moment ( just under 1 second) for the solder to flow, then remove the iron. Dont move the iron around when its in contact with the pad and only leave it on there for long enough to heat the joint.

It looks like the solder you have used had flux in it ( thats good ) but there is now used flux on the board. Before you re solder any joint use a cotton bud ( or q-tip in US) with some rubbing alcohol and try to clean some of that off. Used flux is just contamination on your board that will make soldering harder.

Try to get 60/40 leaded solder if you can, it much easier for inexperienced users as it flows much better and at a lower temp. ( honestly everyone should use leadded, the joints are less likely to fail due to mechanical stress )

Once you have done that can you take a closer photo of that number 5 key , the pad looks damaged! Dont worry we can fix that , but i need to see it closer up.
Thanks for the reply. Luckily, I have been able to fix the issue. By taking a better look to the pcb, I noticed the trace that starts from the pin near the esc label and connects all the switches in the same row. So i connected the esc switch to the 1 switch and so on, up to the 5 switch that worked fine. Now the keyboard work!

andrewjoy

08 Oct 2019, 14:17

Findecanor wrote:
04 Oct 2019, 15:49
andrewjoy wrote:
04 Oct 2019, 14:50
Try to get 60/40 leaded solder if you can, it much easier for inexperienced users as it flows much better and at a lower temp. ( honestly everyone should use leadded, the joints are less likely to fail due to mechanical stress )
Unfortunately, there is recent EU regulation (March 2018) that restricts sale of leaded solder to hobbyists.
You would have to buy it through a registered business or order it from abroad and hope that it does not get caught in customs. .. or find a seller that just doesn't care.
Thank fuck we are leaving that burocratic mess

Findecanor

08 Oct 2019, 18:36

Apparently, some Swedes have been buying theirs in neighbouring Norway, which is outside the EU.
I got a temperature-controlled fast soldering iron that should be better when using unleaded, compared to the normal stuff.

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