Please Help! LM2596 Capacitor Fix/Capacitor to filter the power going to the CPU

[fnice]

Need Some help - trying to repair my self, not sure what Size Capacitor to use & what Legs of the LM2596 to connect to, how can I prob the LM2596 Chip to figure out what sends info to the CPU / Thermistor as reading go up & down a bit, th3d thinks it's possible that who made the main board used a branded lm2596 but could be really LM2576. but says it fixes the Issue - the ALIexpress link is only for Reference. the main board is same as on the TH3D link. Anyone able to help me figure this out where to add a cap, what size & what legs to attach it to? 

https://www.th3dstudio.com/product/creality-cr-10s-v2-0-board-repair-temperature-fluctuation/

https://www.aliexpress.com/item/LM2596-DC-DC-Buck-Converter-Step-Down-voltage-Modules-Power-Supply-Output-1-5V-35V-DIY/32802718261.html?src=google&albslr=200975336&isdl=y&aff_short_key=UneMJZVf&source=%7Bifdyn:dyn%7D%7Bifpla:pla%7D%7Bifdbm:DBM&albch=DID%7D&src=google&albch=shopping&acnt=708-803-3821&isdl=y&albcp=653153647&albag=34728528644&slnk=&trgt=61865531738&plac=&crea=en32802718261&netw=g&device=c&mtctp=&gclid=Cj0KCQiAwKvTBRC2ARIsAL0Dgk029MuqTVodp7aDmyNYdzoyj2O7d0IRX_ZlPmGXtu18c3uC-4VWgh8aAilVEALw_wcB

[Bashstreet]

Use a ruler ?

[fnice]

Figured it out. the board is not within spec for the LM2596 - not sure check the Data Sheet is your Board within Spec. it will be

[Armadillo]

I read the TH3D merely change the capacitor marked as RED BOX.

You can try aluminium electrolytic capacitor 680uf @ 35V or bigger one 1,000uf @35V.
Positive on Pin 1 and negative on Pin 5 or Pin 3 [same gnd].

You do not need a external LM2596 from Aliexpress.

You need to glue down the cap with pcb hot adhesive as the soldering is only piggybacked onto the LM2596.

[fnice]

he is following my Guide now, replacing the surface mount cap, as piggy back is only a bandaid to the real issue, replacing to spec will be more stable. also in the spec sheet for the LM2596 it says max 40v he was using 63v so best to stay within spec 35v 220 uf cap like above pic's show.

[mr6k]

Fix for Hictop CR-10 Extruder temperature variation and struggle to get to 240 degrees C, let alone to the 250 degree specification.

I was having several problems with a new CR-10.

Could not get Extruder temperature above 230 degrees, and then it fluctuated +/- about 8 degrees. Could not get bed above about 60 degrees.

Searching the net, I saw that a fix for the CR-10s board had overcome the extrude fluctuation. (But CR-10 board is a different design.)

Being an electronics engineer I took a deep breath, opened up the control box and went to work on it.

The 12v to 5v chip is a MP1584 rather than a LM2596. However the 5v to the processor was suffering from lots of HF ripple, just like the CR-10s

Also the capacitor that was supposed to smooth this (ringed RED in Modification photo) seemed to be wired incorrectly, although I never got to the bottom of how. Nevertheless I fitted a 47uf 63v and 0.1uf 100v capacitor between the inductor output and ground as shown in photo.  No more fluctuation in extruder temperature also could now easily get to 240 degrees, holding within 2 degrees.

The capacitors voltages only needs to 25v or more. Fitting the + side is a bit tricky as the inductor tab is behind the inductor as shown in the modification photo.

To give a bit of “boost” to both extruder and bed heaters I then carefully adjusted the 12V power supply to 12.5V (well within a 5% tolerance.). Now I can get to a steady 250 degrees on the extruder, haven’t tried higher, yet!

Now to the bed temperature.  I fitted under and attached to the bed a thin (about 8mm) sheet of expanded polystyrene ceiling tile, to prevent heat loss from below the plate.  Attached around the edges with Kapton Tape. Now with this and the 12.5V power adjustment I can get to at least 85 degrees C.

Guess I need to run for few days to check it all holds up.

[mr6k]

OK,
Been running the modified CR-10 with PLA, regular ABS and up Plus high temp ABS.

All stable and can achieve  extruder temp upto 259 degrees and bed temp up to 91 degrees (not tried higher) with room ambient of 20 degrees.

Did have one issue the other day, Extruder temp behaved oddly again not getting to 240 and wandering around. Checked my mods, all OK. Noted that if this happened, then switch off and back on, reload job and run immediately and temps come up ok. This happened 3 times the other day, but not since and have made a good 10 prints over several days since then. I guess there maybe a bug in the boot software that causes a glitch in the extruder temperature routine on some boot ups.

cheers