Another damaged board

Agniusm

I am clumsy and sometimes rush into making things.
I have repaired damaged fan fets but i have noticed black spot on one of my spare board. Can someone help identify this part? Attached photo of the part in red rectangle.
Thank you!

droftarts

@Agniusm It's the 3.3V regulator. I think this thread covers everything you need to know: https://forum.duet3d.com/topic/17515/4-legged-chip-blew-after-messing-with-end-stops

Ian

Agniusm

@droftarts thank you. This is great.
Sadly i cant get it locally. Wander if there is similar part that could be used instead of AP7361C-33E-13

T3P3Tony

@Agniusm said in Another damaged board:

AP7361C-33E-13

where are you based? the datasheet is here: https://www.diodes.com/assets/Datasheets/AP7361C.pdf

There may be similar regulators available with the same pinout local to you.

Agniusm

@T3P3Tony i am based in EU, Lithuania. Probably will have to order from abroad.

T3P3Tony

@Agniusm not sure what farnell's delivery costs are:
https://lt.farnell.com/diodes-inc/ap7361c-33e-13/ldo-fixed-3-3v-1a-40-to-85deg/dp/3482978?st=ap7361c-33e-13

also eu.mouser.com have it.

Agniusm

Thanks. Will try to order from them.

Agniusm

So i hooked up the board to check it further. I also ordered voltage regulators. Looks like it had more damage. Luckily i have a clone to compare(left one is original):

There is LED lit near 036N04L transistor and it shows zeroes.
Wander what else could be damaged.
I have checked AP7361C-33E-13 and visually it has damage like on this writeup and photo:

but it outputs 4.9V
I have 24V output on one of the extruders and all LED's are lit except for 3.3V
Network shows no life, no LED's come up.
I am on 24V PSU.

A Former User

if the 3.3v regulator (U2) outputs 5v then odds are you need to replace the ethernet chip and processor as a minimum as well.

that the bed heater led is a result of the mosfet TR2 being turned on, it is controlled by U11 which in turn is controlled by the CPU so either could fail. to determine which is failed you'd need to follow the signal from the gate of TR2, pin 4 of U11 to pin 5 of U11.

(From the LED colours shown neither is original Duet board but as long as you don't rely on the colour of the LEDs for diagnostics it doesn't matter much in this context.)

edit: might be usefull https://github.com/Duet3D/Duet-2-Hardware/blob/master/Duet2/Duet2Maestro_v1.0/Duet2Maestro_Schematic_v1.0.pdf

Agniusm

@bearer said in Another damaged board:

if the 3.3v regulator (U2) outputs 5v then odds are you need to replace the ethernet chip and processor as a minimum as well.

This is odd. I have checked U2 on the undamaged clone board and it outputs roughly the same voltage. It was weird for me too as it was 3.3V regulator but outputting almost 5V

A Former User

It should have 5v on one pin, 3.3v one another + ground. Are you seeing 5v on both input and output?

Agniusm

@bearer i had 0 on one pin so i guess i just had bad contact when measuring.
BTW what do you mean neither is original? The one on the left is def original. Clones have a brand on eth while original only serial. I purchased original from Duet3d:

dc42

Looks like the 74HCT02 mosfet driver chip has failed, because all the heater LEDs are on. This happens if the 5V rail is shorted to a higher voltage. If the 3.3V rail was at 5V then the W5500 Ethernet chip and SD card will have failed, and perhaps also the processor.

A Former User

@Agniusm said in Another damaged board:

left

d'oh, so I clearly can't tell left from right .. somehow thought the all green led one was the defective. my bad!