There is a link in the description. Idk if it still works though… I will check later

I tough about that several times, but I haven’t had enough time to make extra content… As you can see the last half an year or more there was not a single video

If you bought a second-hand device you probably just got scammed. If you purchased it from a legit marketplace ask for a refund.

The handle is T210 and it uses C210 tips.

Thank you so much

So first you can check if all the voltages are present on the board. 4 of them are produced by the chip right behind the USB-C port. If I am not mistaken there should be 3.3, 1.8, 1.1 and 1.0V (in some cases 2 rails of 1.0V instead of 1.1V) +-100mV aren't that critical. You can measure them from the caps and coils around the chip, just be careful not to short anything while measuring. The other one which is CPU power on some revisions is located right behind the 2 HDMI ports. It's a very tiny BGA crystal package (shiny and rectangular with no visible solder joints) between it and the SoC there are some caps that should read something about 0.7 to 1.8V when powered on. The one I found to be shorted in the video. Lastly you can check for one even tinier BGA crystal chip, that in some cases is near one of the edges of the SoC and in other cases is on the bottom side of the board. I am not really sure how you can measure if it's ok, the only thing that comes to my mind it to use a magnifying glass or something to check if it's cracked or chipped. If that's the case you will need to replace it, but the only source I can suggest is a donor Pi... I hope this helps! Replay here if you need more help later.

I mainly order replacements from Aliexpress

Well there could be several reasons for this to happen... Here are a few of them with possible solutions. Check if all the voltages on the board are present. There are 4 voltages that are generated by the chip right behind the USB-C. Either MXL7704-P4 or dialog DA9090, there should be: 3.3V, 1.8V, 1.1V, and 1.0V if I am not mistaken there is a slight difference in the last to voltages depending on the revision so is the measurements are within + / - 0.2V it should be fine. And the last voltage that I am pretty sure is for the SoC and not the RAM is 0.8V if I remember correctly and it's generated by the DA9121 which is behind the HDMIs There might be a so-called gray pad issue, or one of the pads on the board might have a bit more corrosion than usual flux can handle, it may appear as a darker shade of gray and if you try tin it with your soldering iron it willn't tin at all (the same thing happens when you try to solder the memory chip - the solder ball over it gets melted but can't make a contact with the pad) if that's the case the solution is as simple as taking an exacto knife or something sharp to very gently scratch the surface of the pad. Another thing that comes to my mind is maybe there are some loose pads on the board side that doesn't make a connection with the traces leading to the CPU. You can check for that with a multimeter in diode mode, placing the red probe on GND and using the black one to probe every single pin on the board that's connected to the CPU. You can use an LPDDR4 pinout diagram to see which pins carry signal. If you find a pin that should is used for signal aka should be connected, but the multimeter says O.L. (Open loop), then that's your problem. If the pad itself is looking loose or disconnected from the rest of the trace, that's good because you can repair it, but if the pad is looking alright probably there is a bad solder joint under the SoC, which sadly cannot be repaired as there are no stencils for this SoC on the market. If none of the above help, there is always the possibility that you might have killed the RAM chip during soldering or re-balling or it might even be DoA (dead on arrival). I really hope this is helpful! Let me know if you make any progress!

@@MadEDoctor So far I've only tried on one Pi. I checked all voltages on it and 5V, 3.3V, 1.8V, 1.1V and 1.0V voltages were present. Then I looked closer and it looked like the RAM BGA was a bit lifted on one size. I suspected the solder balls were differing sizes. So I removed the RAM chip again, then reballed and triple checked that I had uniform solder ball sizes. I got the RAM chip reattached to the Pi,waited for it to cool, and then plugged it in. Now the Pi has constant blinking really fast and nothing shows on screen... I'm wondering if I killed it :(

Just checked voltages again and only 5V is present... Guess I need to figured out what I messed up.

@@JamesonRicks That’s kind of bad especially if you have the newer revision that uses the dialog DA9090 as if it’s dead it’s literally impossible to buy as replacement part…

Sadly, no, because there is a CPU limitation.

@@MadEDoctor I forgot the RAM on PI 3 is part of the microcontroller.

Yeah, I think so.

Let me take a closer look at the Pi 5 and I will write you back later with possible solutions.

Sadly I don't think there is something that can be done about it... Becuase the Pi foundation has designed its own main PMIC and USB (I/O) controller, which to my knowledge they decided not to make them publicly available and so can't be purchased as spare parts. And so you are now a proud owner of a brick, unless are still under warranty, then you can contact the store you got it from.

Yes i have bought it 1month ago

Can you help me with the warranty process

@@alltogether5609 I believe you should just contact the place you bought it from and say that your Pi just stopped working and you would like to return it under warranty.

If you live within the EU you can fill out my mail-in form here: rb.gy/v6izn If you live outside of EU I would suggest you to search for other KZbinrs who are doing microsoldering repairs, that might be local to you.

Here you go ;) Micron D9ZCL | MT53E2G32D4NQ-046 WT:A - 8GB Chip : rb.gy/agrf

Bga work and new to soldering never ever goes well dude. But you can defo take the chip and instructions about jumpers to a microsoldering shop near you ( usually decent phone repair shops do microsoldering ). But i have to warn you , you migjt as well just buy a new rpi with the ram you need , microsoldering jobs are expensive.

Check the description of the video :)

True , i cringe at the sight of those rpi clusters when an old mini pc can do the same job with similar power comsumption. The reason i use rpis is for the gpios which you dont get on mini pcs.

Yeah, that's true. But I think running a memtester is better, because there is always a chance that even a brand new chip could be defective.

Check if there is 3.3v present on the board. The easiest way is to test at the gpio header, but be careful because if you accidentally short 3.3v to gnd or 5v it will fry the PMIC

Yeah, the original RAM capacity of the Pi doesn’t really matter. You can take whatever is the cheapest Pi 4 including the Pi 400 and swap the RAM chip to whatever capacity you want (i mean in the 1 to 8GB range)

I haven't looked in detail yet, but the Raspberry Pi 5 uses RAM which has the same footprint as the RAM on the Pi 4. Having this said I am pretty sure it will be possible to upgrade its RAM, even using the modules that were found on Pi 4. If I am not mistaken the Pi 5 uses LPDDR4X and the Pi 4 uses LPDDR4. I think the only downside will be that the old chips are a bit slower on paper, but that's hardly noticeable IRL. I am thinking about trying it myself and making a video about it, but I am not so sure when I will have the time to make it.

It works on all revisions of the Pi4

@@MadEDoctor Have you tried it personally on older revisions? I tried upgrading my Pi4 today and got black screen and nothing on UART. Tried reflowing the memory and then reball on leaded solder, but it didn't help. My board is of older revision. I didn't check it beforehand while board was still working, but I think it's 1.1 or 1.2. So, I wonder if I got faulty IC or is it wrong board revision... Do you know what resistance it should be on ram's power rail with D9ZCL soldered?

@@aspinx I have tried on 1.1 and it worked just fine. As for the resistance I have no idea. But probably should be more than a couple of ohms at least. >=10ohms I guess.

Do you have a blinking code for missing RAM? I think it was 7 or 8 fast blinks on the green LED

@@MadEDoctor Yes, the LEDs were blinking fast about 8 times or so. Turned out he issue was with soldering. Reballed RAM again and this time it worked! Board revision is 1.2, according to /proc/cpuinfo and so far all 8Gb are working! Thanks for making this video and for your help!

Yeah, at least I think so.

Nope, only with CM4.

Unfortunately not 😅