HW fly - RP2040 - No Boot - Green Flashes - Switch v2

[GnobarEl]

Hello all,

HW fly - RP2040 - No Boot - Green Flashes - Switch v2

I've been using this chip for 3 months and so far it worked perfectly. However, one of these days I was playing and suddenly the image froze completely.
I forced to power off and since then it only boots for the OFW.
I can see a green LED flashing, but always boots to OFW. No matter if I press vol down or if I remove the SD Card.

Please check the video of the green light from the chip.
Anything I can do?

PS. I tried to connect to PC but the device is not recognized. I think the connection with the PC is not working. So I can update the firmware.

[EDIT] Thanks to @bennet321 and @cherup! The issue was with the flatcable capacitor cold solder joints

Thanks.

 

[bennet321]

Try another SD card loaded with HATS pack

 

[GnobarEl]

Try another SD card loaded with HATS pack

The issue is not with the SD card, since it doesn't even show the message "no SD" on boot. I mean, if it was an SD card, I should be able to see that screen. But it always boots directly to OFW.

 

[cherup]

You should check your flex cable installation (SP1 / SP2) Blink code I'd interpreted as "CPU always reach BCT check (no glitch reaction, checkmosfet)"

 

[bennet321]

The issue is not with the SD card, since it doesn't even show the message "no SD" on boot. I mean, if it was an SD card, I should be able to see that screen. But it always boots directly to OFW.

Ah ok I see what you mean. I was at first thinking this was hwfly. It probably is a connection or chip issue then

 

[GnobarEl]

You should check your flex cable installation (SP1 / SP2) Blink code I'd interpreted as "CPU always reach BCT check (no glitch reaction, checkmosfet)"

What is the best way to clean thermal past? The Capacitor is full of solder past and I don't know how to clean it. Without a microscope it's very hard to see the solder joints.

 

[bennet321]

What is the best way to clean solder past? The Capacitor is full of solder past and I don't know how to clean it. Without a microscope it's very hard to see the solder joints.

I think you mean thermal paste. Best way to clean it with IPA and a qtip

 

[GnobarEl]

I think you mean thermal paste. Best way to clean it with IPA and a qtip

Yes, my fault, you are correct. It's thermal past. I will try to get some Isopropyl Alcohol. Thanks for the tip.

 

[GnobarEl]

You should check your flex cable installation (SP1 / SP2) Blink code I'd interpreted as "CPU always reach BCT check (no glitch reaction, checkmosfet)"

I checked. Looks ok. Any way to make sure the capacitors soldered correctly to flat cable?

 

[GnobarEl]

Hello! Any more tip? What can I do?

Thanks.

 

[bennet321]

Hello! Any more tip? What can I do?

Thanks.

If you are certain everything is connected properly then it might be time for a new chip. You could try taking some diode readings with a multimeter and comparing to those online. Also how are you checking the connections. They need to be checked under a microscope or something similar. You won't be able to make a judgement with the naked eye

 

[Hayato213]

You can try a rcm jig to reset the chip

 

[GnobarEl]

If you are certain everything is connected properly then it might be time for a new chip. You could try taking some diode readings with a multimeter and comparing to those online. Also how are you checking the connections. They need to be checked under a microscope or something similar. You won't be able to make a judgement with the naked eye

Hello,
I'm checking with the zoom from my mobilephone. It's not the same as a microscope, but its the best I can get.
Regarding the "diode readings with a multimeter" can you provide a guide? I couldn't find anything relevant.

Thanks.

 

[bennet321]

Hello,
I'm checking with the zoom from my mobilephone. It's not the same as a microscope, but its the best I can get.
Regarding the "diode readings with a multimeter" can you provide a guide? I couldn't find anything relevant.

Thanks.

Basically you put your multimeter into diode mode, you will put your red probe on GND and then you would take a reading with the black probe on the sides of CPU capacitors connected to the flex cable that are not connected to GND. You should get a value anywhere from 0.5 to 0.8 if everything is good. To be honest though I think you have a connection problem(most likely) or the chip had died considering it was working fine for a time. I don't think it is the switch itself considering it still boots OFW

 

[GnobarEl]

Basically you put your multimeter into diode mode, you will put your red probe on GND and then you would take a reading with the black probe on the sides of CPU capacitors connected to the flex cable that are not connected to GND. You should get a value anywhere from 0.5 to 0.8 if everything is good. To be honest though I think you have a connection problem(most likely) or the chip had died considering it was working fine for a time. I don't think it is the switch itself considering it still boots OFW

Thanks for your detailed reply. Later on I will try. In anycase, I bouth a new chip. Soon as I get it I think we will be able to understand better what's going on. Thanks for your help.

Post automatically merged: Sep 12, 2023

Hello all,
@bennet321 and @cherup you were correct! I double-checked and the issue was with the flexcable connections. The solder from the capacitors wasn't good. Colder joint! I heat it a little and everything is working properly.

Thanks for your support!