Can’t figure out why my PI4 won’t boot up. Have the HDMI and ribbon cables extended but power LED only flashes green three times and goes back to red. PI4 works fine on it’s own. Any suggestions?
Check the connection of the bridge board, it can be miss-plugged
double/triple checked all of the cables on the board. Removed and reinstalled the ribbon cables - all looks good. The hub seems to be secured as possible to the board as well. Tested with a Pi Zero just for the hell of it with same results. Don’t have a Pi 3, so unable to see if it’s a problem specific to the hub or board.
It’s hard to tell from the pictures, but to me it looks like the bridge is offset to the right. Check if you can insert the screw.
Also your flat wire cable looks odd. The white side is typ. used as Pin1 indicator; you have it the other way around. have you measured your GPIO40 before you’ve connected the bridge? Is Pin1/2 in the correct position?
I’ve mad a similar test but used a different cable like https://shop.pimoroni.com/products/40-pin-gpio-extension-cable?variant=32246715580499 -> please mind their note in the product description!
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Looks like it was the cable. Also got a thin ribbon USB cable. Working like a charm. Thanks for the help!
I seem to have scored a couple of CM4 boards, so I bought a couple of the CM4 to Pi 3B adapters. Has anyone tried to build a Pi-Top with one of these setups yet? I’m pretty sure it will fit (maybe a little bit high, but within coping distance). Heat: It looks like the CM4 SOC metal chip lid will be hard against the green plastic bottom of the laptop. I don’t have any great ideas for this. I could cut a window in the bottom, but I don’t think that would be very effective. I’m not going to use this as a compute cluster, but… Hmm. How about a thin aluminum heat spreader like the Pi-400? It would have to thin, but maybe that would be a reasonable solution and keep the bottom of the laptop intact. I also have one of the aluminum Astro-Pi cases, that take Pi 3’s, so I am hoping the Waveshare adapters are good.
rpiMike posted about this in the above thread.
Don’t do this. Don’t spend your money until we come up with some better way.
Given the Waveshare CM3 to Pi 3B adapter, which mounts the CM4 on the bottom, it just plain does not fit. @Tom-B, above had to cut a whole in the bottom of the laptop the full size of the CM4. From my efforts to just squeeze it in somehow, I think he’s exactly correct about this. There are several problems, but the big one is heat. It can’t use any heatsinking from the metal bridge, and just cutting a hole in the bottom isn’t going to allow convection.
I was hoping to get it to just fit and then buy some aluminum sheet material to make a heat spreader across as much of the case bottom as I could. That’s how the pi-400 does it.
Can’t second this!
Also made such a mod, covering the resulting hole with a piece of GFK.
The PI is just working fine. Keep in mind that a CM4 is designed to work without cooling.
Adding a alu plate (with some TIM material to the SOC) will result in the alu getting hot to the touch! One can burn its finger touching it.
Having the CM4 on top of the carrier would be beneficial, but there is no such carrier around.