Hi, I am trying to fix a switch with emmc issue but to confirm everything else works ok, I boot into RCM and with injecting heckate I get no backlight or display but if I inject atmosphere I get the below image… any ideas why? its the same with another screen and with and without the emmc module
Try injecting the Biskeydump payload and take a photo to show
If you remove the shield over the SoC/Ram, I use a blade in the latches and twist to remove, after load that Biskeydump payload again and put slight downward pressure on the ram modules and see if those graphical artifacts change, if they do then it’s likely a connection issue with the ram and a reflow may resolve
Thank you, it does make a difference so will give it a go.
Hi Severence, been busy with work and decorating but I did try reflow last night and that didn’t help, I took it off and used a mask to add new solder paste to reball it and its still the same when back on. The board is slightly bent so not sure if all balls are making a connection or not.
Could the ram chip itself be bad and need replacing or is it more likely the pads are not making a good connection?
Same graphical artificating?
I’d verify that putting slight pressure on the SoC while Biskeydump is loaded up that that doesn’t also change/resolve the graphical aritifacts too, as it may be a possible SoC issue or joint problem if it does
They very rarely fail and the most common faults surrounding them is joint issues. I’ve started using preformed 0.35mm balls using the “corner ball method” for Switch ram as solder paste always results in undersized and sometimes possibly uneven balls which is a problem if the board has any significant warping. Example here, though you want to practice this technique on some scrap ICs first to get a feel for it.
Thanks for the tips, CPU doesn’t seem to make a difference which should be a good sign i suppose.
Ordered some 0.35 balls last night and will have another go when they arrive, see if it makes a difference and report back then
Finally got round to reballing the ram IC and that was a pain. Found out the hard way that not every stencil is the same and mine is not a direct heat one so warped under heat and the balls rolled off the chip. Ended up following guide by thecodr to do it manually and after a few attempts managed to get the knack of it, the right airflow and temps and was actually quite chuffed with how it came out.
That is however where the good news ends. Still have graphical issues, so reflowed the other ram, reflowed the CPU and got slightly better to be able to read some of the text and was getting failed to init emmc, tried another module to see if it was the mainboard or emmc and it read another one so emmc is no good.
Tried atmosphere to see what it would do and it loaded the splash screen then went to fatal error.
To be honest, with the warped board, graphical issues and bad emmc I think this board would be better suited as a donor rather than wasting more time trying to fix it when it will never work as a normal switch and wouldn’t trust it to last even if I resolved the rest of the issues.
Thanks for your help along the way
Pretty sure it will be a direct heat stencil as the dedicated ones for the jig are 80x80 or 90x90, it’s pretty typical for direct heat stencils to warp/buckle, to minimize this try using a lower temperature of about 320 and maybe even slightly lower which is more than adequate, try heating the whole stencil up from a distance not just the array your interested in this will minimize the buckling, you can also cut out the ram pattern with a dremel which will also help for next time
Yeah think your right, it’s SoC related by the sounds of it