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Under voltage warnings on RetroFlag NESPI case - best power supply?



  • @foldedpencil so I got my new nespi case and even got to keep the old one. Still having the same issues. Guess I have to try a new power supply. NES label was kind of a pain to put on (I chickened out, and had my wife do it) but it looks great



  • The one thing I noticed with the NESPi cases (I have two and both exhibit the undervoltage warnings) is that the wires used for power inside the case might be causing considerable resistance and essentially dropping voltage to the Pi.

    Might first suggestion is try a 5.2 V rated power supply (with 2.5 A or larger), as mentioned above, and see if the undervoltage indicators go away. If not, my second suggestion (in my case for both cases) would be to replace the wires (noted with cyan arrows) with thicker gauge quality wires. Once I did that, did not have any issues with undervoltage issues. The wires I used were 22 gauge stranded wire.

    alt text



  • @iggy could you post some pics of your GPIO mod?



  • @markrmonaco Ill see about posting some pics with a new nespi build....the other two builds have hot glue covering the terminals.



  • @iggy Where did you get a spare dual row jumper connector or do you know what that part is called? Also, are the other end of those leads soldered?

    Also, do you run psx and n64 games on this wired setup without voltage issues?



  • I posted this in another thread and wanted to share it in a few posts related to this, as I followed @iggy 's solution:

    "I wanted to add some findings to the power issues on this case.

    I had both a Canakit adapter 2.5a and a Pi Hut 2.5a power supply. I don't know if some of it is just bad luck or manufacturing, but I had power issues even scrolling through my game list ( which is a video preview list, not just screenshots/box art).

    I decided to solder new larger 22 awg pos & neg input power wires (the ones from the power input/buttons board on the case that runs to the other board which sits under the usb/ethernet circuit board). Replacing these wires cured my lightning bolt issues. It seems that the other wires are fine for voltage but as many speculated, the main power input wires were not thick enough and too much current/voltage was lost after running through the power/reset button board. All seem so be well and am even playing N64 games without any voltage issues. This is with a gampad and a keyboard plugged in, with wifi on, and a third wireless input (ps3 controller ) all being active at once.

    Hope this helps."



  • I posted this on a different post but
    Hey guys iv been playing with issue for a little bit and was thing how was the power getting to the pies motherboard and think its getting its power from the usb port and the 5v fan pins.
    This had me thinking a long time back I connected a usb powered hub to one and found that the pie stayed on even if I disconnected the power from the pies micro usb port, but the under voltage symbol work come on and the machine would start to run very slow.
    So what iv done is solder to wires from the nespi case power and reset switch circuit board( theres 3 pairs positive + and negative - wires coming on and off it)
    I used the middle + and - to run a wire to the pies board (had to solder wires to board) positive + PP2 and negative - PP5 points on the underside of the motherboard near the micro usb port.
    This seems to have fixed the problem so I tested the pie by running 007 golden eye for the n64 (had the left dpad stuck down so the character would spin around over and over) for and hour and then tried Mario kart 64 (did the same thing with the buttons) for an hour then tried G-police 2 for the ps1 (same again with the buttons) for an hour I dident get under voltage fault.
    So I hope this will help im going to buy a few more nespi cases and try with them to se if it works with them too.
    Hope this helps



  • @furboyxr8
    Can you please create a video for this?
    I’m familiar with soldering as I’m a structural concrete engineer.
    Video or images can help me to fix this irritating problem.



  • I had this problem, you basically disable one power line

    All I did is get long nosed pliers and removed that contact from the USB plug going to the PI from the powered hub. A bit brutal but it worked

    I'll hunt it down after work, not much time at the moment



  • Not the exact diagram I used originally, but this one will still show you the pins to disable or remove

    https://www.psdevwiki.com/ps3/File:Usb-pinout.png

    You need to disable/remove the +5v/VCC power. This will then turn that USB cable into a data only cable. As your hub is a powered USB hub this won't matter. Thats why when the PI is off its still powered as the hub is now feeding +5v back into the PI. Not a great idea as its not really designed to be powered from a USB connector plus the problems this could cause with too much current draw through the USB connector that the PI needs

    Either by removing the pin that supplies +5v in the USB plug to the PI or carefully peel back the cable insulation and snip the red wire for the +5v



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