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by RGJ-PI
Tue Oct 01, 2019 12:31 pm
Forum: Troubleshooting
Topic: Smd component fails
Replies: 2
Views: 124

Re: Smd component fails

That part is a 100nF capacitor used to decouple the memory. Provided it is cleanly removed and there are no pad shorts with old solder etc then the board will almost certainly work fine with it missing as it is one of six 100nF caps for this chip.
by RGJ-PI
Tue Aug 27, 2019 1:23 pm
Forum: Troubleshooting
Topic: Raspberry pi 3B
Replies: 2
Views: 82

Re: Raspberry pi 3B

I'm guessing you previously asked this on StackOverflow but if not..

The github clone link on that IOTA doc step 2 is incorrect. Try

Code: Select all

git clone https://github.com/caddyserver/caddy.git 
instead and continue with step 3 onwards.
by RGJ-PI
Mon Aug 19, 2019 11:17 am
Forum: Beginners
Topic: Charging Indicator
Replies: 4
Views: 919

Re: Charging Indicator

If you are just interested in measuring charge current then Texas Instruments make a very easy to use current sense chip that you can read directly on a Pi with simple Python script.
http://www.ti.com/product/INA260#
by RGJ-PI
Fri Aug 16, 2019 9:50 am
Forum: Troubleshooting
Topic: Missing Green LED
Replies: 1
Views: 108

Re: Missing Green LED

When you say missing, do you mean it was missing from new or it has been mechanically damaged since you've owned it? If the former could you take a close up picture of the missing led area and also the SN barcode on the underside near the micro sd card socket so we can check the build record.
by RGJ-PI
Mon Aug 05, 2019 3:19 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 - Dead USB, no VBUS
Replies: 12
Views: 551

Re: Raspberry Pi 4 - Dead USB, no VBUS

I have messaged you on Twitter as requested with an email address to send the package info the couriers will need. Once received we will send a shipping label pdf accross to you.
by RGJ-PI
Mon Aug 05, 2019 10:32 am
Forum: Troubleshooting
Topic: Raspberry Pi 4 - Dead USB, no VBUS
Replies: 12
Views: 551

Re: Raspberry Pi 4 - Dead USB, no VBUS

Hi ProfSparkles. I've spoken to James this morning and I see he has confirmed the circuit with a part schematic image. Would you be able to send the faulty board back to us so we can look into the failure mode please? We will ship a replacement board to you on receipt. If you are okay with this then...
by RGJ-PI
Thu Aug 01, 2019 2:30 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 - Dead USB, no VBUS
Replies: 12
Views: 551

Re: Raspberry Pi 4 - Dead USB, no VBUS

It's a N Channel enhancement MOSFET
by RGJ-PI
Thu Aug 01, 2019 9:08 am
Forum: Troubleshooting
Topic: Raspberry Pi 4 - Dead USB, no VBUS
Replies: 12
Views: 551

Re: Raspberry Pi 4 - Dead USB, no VBUS

It is pulled to 3V3 with a 10k resistor but should be pulled down to 0V by the VL805 in normal operation. Sounds like something is unhappy with the VL805 if it's not being pulled to zero. I'll speak to James Adams about this when he is back in the office on Monday.
by RGJ-PI
Wed Jul 31, 2019 7:09 pm
Forum: Beginners
Topic: gpio-shutdown
Replies: 6
Views: 452

Re: gpio-shutdown

Assuming you are using some sort of external Voltage monitoring chip to drive the GPIO pin when low Voltage is detected, could you not use the same GPIO line as a manual shutdown with a push button switch? If you put say a 10k resistor in-between the PSU supervisor chip output and the PI GPIO you co...
by RGJ-PI
Wed Jul 31, 2019 7:01 pm
Forum: Beginners
Topic: Need help mapping out multiple things to Raspberry Pi
Replies: 5
Views: 170

Re: Need help mapping out multiple things to Raspberry Pi

If it were me I'd use a suitably rated (to suit the misters, fans and Pi) external 5V power supply. Power the fans, mister/humidity etc directly from the PSU outputs. Power the Pi directly into the 5V and GND pins on the GPIO header. The DHT22 and DS18B20 sensors you mention will be fine running off...
by RGJ-PI
Wed Jul 31, 2019 6:46 pm
Forum: Beginners
Topic: 5V Solutions for Multiple Sensors w/o Breadboard
Replies: 4
Views: 135

Re: 5V Solutions for Multiple Sensors w/o Breadboard

All depends on how many sensors we are talking about and the current requirements of them. If low then daisy chaining power and ground from one to the next should be fine. Your sensors might need decoupling capacitors too as I don't know if you are using just bare IC sensors or sensors on a small pc...
by RGJ-PI
Wed Jul 31, 2019 6:33 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 - Dead USB, no VBUS
Replies: 12
Views: 551

Re: Raspberry Pi 4 - Dead USB, no VBUS

The AP2552W6 enable pin is pulled to 5V with a 10k resistor. It is isolated from the VL805 by a MOSFET depending on reset condition of the board. This MOSFET could have died open circuit I guess but difficult to see how that would have occurred. Unfortunately I don't have access to the VL805 datashe...
by RGJ-PI
Wed Jul 31, 2019 6:27 pm
Forum: Troubleshooting
Topic: Lightning bolt on certain sd cards
Replies: 7
Views: 224

Re: Lightning bolt on certain sd cards

What model Pi board is this on? The official PSU's output 5.1V to allow a bit of voltage drop in the cable.
There's a good chance that even with a PSU capable of 3A output, if the connecting cable isn't thick enough the wire Voltage drop will cause the low input Volts lightning symbol.
by RGJ-PI
Wed Jul 31, 2019 6:05 pm
Forum: Troubleshooting
Topic: 0w SMD component missing Wifi+Bt not working
Replies: 10
Views: 376

Re: 0w SMD component missing Wifi+Bt not working

Nice one. Recycling old parts and bringing something back to life. Glad it worked out.
by RGJ-PI
Tue Jul 30, 2019 10:55 am
Forum: General discussion
Topic: Fan header pins?
Replies: 25
Views: 1264

Re: Fan header pins?

As already said, that would be bad, and it's highly unlikely a 5V fan would run at only 1.7V anyway. The correct way to slow a fan down is with PWM (a technique of pulsing the power at the correct voltage but at varying pulse widths and intervals). Strictly speaking using PWM on the main power inpu...
by RGJ-PI
Tue Jul 30, 2019 8:58 am
Forum: Troubleshooting
Topic: 0w SMD component missing Wifi+Bt not working
Replies: 10
Views: 376

Re: 0w SMD component missing Wifi+Bt not working

The part in question is a Murata ferrite bead filter. Specifically this part..

https://uk.farnell.com/murata/blm18ag60 ... dp/1400924

If you have suitable soldering equipment then a 0603 part should be fairly easy to replace.
by RGJ-PI
Fri Jul 26, 2019 11:58 am
Forum: Troubleshooting
Topic: Network fails after rebooting but fine after shutting down
Replies: 74
Views: 2849

Re: Network fails after rebooting but fine after shutting down

I returned mine to Raspberry Pi Ltd. I received an email from them saying that they could not replicate the problem and that they would return my Pi to me. A week later I have still not received it back. My replacement Pi was delivered today. A word of warning for anyone else thinking of returning ...
by RGJ-PI
Mon Jul 15, 2019 2:59 pm
Forum: Troubleshooting
Topic: Raspberry boots but I Cant get to the Desktop
Replies: 5
Views: 168

Re: Raspberry boots but I Cant get to the Desktop

What version Pi board are you using please?
by RGJ-PI
Mon Jul 15, 2019 2:37 pm
Forum: Troubleshooting
Topic: Raspberry boots but I Cant get to the Desktop
Replies: 5
Views: 168

Re: Raspberry boots but I Cant get to the Desktop

If you leave the Pi to boot without using shift for the recovery screen does it boot to a command prompt? Which OS did you select to install when you ran the NOOBS setup?
by RGJ-PI
Fri Jul 12, 2019 8:56 am
Forum: Troubleshooting
Topic: Damaged HDMI after storm on RPi3?
Replies: 8
Views: 436

Re: Damaged HDMI after storm on RPi3?

From your description I think it's pretty safe to say that the SOC has had some nasty voltages applied via the HDMI socket and is dead beyond repair. Quite possible that there's no visible damage to the board it will just be blown silicon structures within the SOC. Which model Pi is it and where are...
by RGJ-PI
Mon Jul 08, 2019 11:13 am
Forum: General discussion
Topic: Heatsinks official for rpi 4 ?
Replies: 44
Views: 6488

Re: Heatsinks official for rpi 4 ?

If size isn't an issue but absolute performance is then this active solution would take some beating..
https://www.seeedstudio.com/ICE-Tower-C ... -4097.html
I think it's safe to say this isn't compatible with the official Pi 4 case!
by RGJ-PI
Mon Jul 08, 2019 9:01 am
Forum: Troubleshooting
Topic: I think my pi 4 is dead
Replies: 13
Views: 989

Re: I think my pi 4 is dead

Hi lowflyer. Yes please return your Pi 4 to PiHut who will provide a replacement unit and will return the Pi to us for evaluation. Hemin. How are the heatsinks fitted to the Pi? Did yo use any heatsink compound or just thermal tape? Which supplier did you purchase it from please so I can arrange a r...

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