NanoPi M4 SATA Hat

[jtreg]

Oops, I connected a 24V power supply to the SATA Hat and I think I blew the diode on the hat. (see photo) Not sure if it is a diode, which way should it be orientated. Stupid idiot for creating the magic smoke, I hope I can repair it. I tried booting the Orange Pi I had already connected to it (because the original NanoPi M4 is missing... Fortunately the OrangePi is OK.

Any advice on where to look if the diode in question does not fix it.

Cheers,

James

[evilm]

This component in the circled area is a diode. It is possible to confirm it by the silkscreen on the board, it is labeled as D1(Diode 1).

The other components up on the silkscreen, C281, C279 and C280 are the three smd ceramic capacitors above the diode.
The diode looks damaged, but the photo is too dark to confirm it. You could clean it a bit and try to read the code of this diode.

Another way to get this information is by searching the schematic, if available, for this board and look what diode is D1.

Also you should check the component U16, it looks damaged, but again cannot say for sure, the photo is too dark.

I guess this board provides 12VDC and 5VDC for the sata drives. Maybe the U16 is the regulator responsible for the 5 volts, cannot say for sure as I don't have this board or it's schematics.
You could replace the damaged components, it may be an easy fix if nothing else is shorted. You should also check if nothing else is defective, don't know if you are experienced with repairing electronics.
If I found the schematics for this board I'll post it here.

Can you read the code on the diode?

And about the orienting of the diode, I guess, by the looks of it in this photo, that the cathode side is towards the silkscreen that says 12V.

 

In diodes, the side with the stripe marking is the cathode and the other side is the anode.

 

Edited February 4 by evilm

[jtreg]

Sorry the photo I took (terrible) I had another go, hopefully you can make out the markings... I used a jewellers loupe to read the markings and made a sketch...

the Diode is marked MOD 12A and has 3 stripes (akin to the banding? cathode side?)

The other component has 12 pins that I can see and has the marking ALTJ 261.

 

Can you suggest alternatives to these, now I have given more info? I don't seem to come up with anything if I search on these identifying marks... thanks for help so far!

[evilm]

I'll take a look upon this tomorrow. For the diode, the side with stripes is the cathode.

By the looks on the photo, it doesn't seems that the other component (the one with 12 pins) is damaged. It looked bad on the first photo you attached to the post. Although I cannot say for sure, it may be damaged, even if it doesn't show any external markings or signs of damage.

In many cases damages like this one, that happened by over voltage, end up in something like just a shorted diode, it all depends on the board design and components used.
You can replace this smd diode with any other that has at least the same specification.

I'll take a look on this diode code tomorrow, there are references for 12A smd common diodes and zener diodes. Although if it was an zener diode it probably would be marked as DZ1 or Z1 on the board. It also could be a TVS diode (suppressor diode), these types are used to protect sensitive components against transients and voltage spikes. 

By the photos, It looks like the diode code is not MOD 12A. I cannot identify the last letter on the first line, the first one is an M and middle one looks like a D. Maybe it says MDD? On the second line I can see clearly the number 12 but cannot identify the last character. Maybe the code is MDD 12A or MDO 12A?

You could remove this diode and test to see if there are any shorts between the 12V, 5v and GND rails. Do you have a multimeter?

If it is a TVS protection diode, you could remove it, and test if there are any shorts left on the board. If no more shorts could be found the board may work without the diode for testing purposes. Is extremely advisable to find a suitable replacement. You need to make sure that there are no shorts on the board if you intend to test it. If there are any shorts on the board and you plug it you could damage the power supply, the orange pi or the sata hdd/ssd.

 

The diode could be the following:

TVS diode: SMF12A (there are pictures of diodes from this manufacturer with the marking MDD - microdiode electronics)

There are other diodes from mdd but since yours seems to be marked as 12A, I guess this one should be the model you are looking for.

 

https://www.lcsc.com/product-detail/TVS_Jiangsu-Yutai-Elec-SMF12A_C123800.html

 

https://datasheet.lcsc.com/lcsc/2401290930_MDD-Microdiode-Electronics--SMF12A_C123800.pdf

 

As I stated earlier, you could replace this diode with any other that has similar specification. 

TVS diode: P6SMB12A (from littelfuse)

This manufacturer also has a 12A diode that has close enough specification.

https://m.littelfuse.com/~/media/electronics/datasheets/tvs_diodes/littelfuse_tvs_diode_p6smb_datasheet.pdf.pdf

 

TVS diode: SM15T12A (from sgs-thomson)

This manufacturer also has a 12A diode that has close enough specification.

http://elektronikjk.pl/elementy_czynne/diody/SM15T6V8C.pdf

 

Edited February 21 by evilm

[evilm]

The other ic, ALTJ 261, I mentioned could be damaged, and also could be the one responsible by the 5VDC rail, indeed is a 5V regulator. It is manufactured by mps(Monolithic Power Systems).

The code for this component is: NB679GD (Model in QFN-12 package)

The datasheet for this component can be found here:

https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/NB679/document_id/4030

You can check the marking references on mps parts here:

https://cdn.badcaps-static.com/pdfs/6821fb00412750dfe538563299cc5945.pdf

and here:

https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/80630-ic-marking-codes-and-datasheets#post1482820

 

I'm sharing this, although it doesn't mean that this ic is damaged, you need to test it to see if it is giving the correct output of 5VDC, and check for any shorts on the board.

The input range for this regulator varies from 5.5VDC to 28VDC. So maybe it did not got damaged by the over voltage from the 24VDC power supply. Maybe the diode protected the other components as well. 

As I stated earlier, you should test for short circuits in the power rails. Test if there is any shorts between 12VDC to GND, 5VDC to GND, and 12VDC to 5VDC.

Maybe only the diode is faulty on the board. It's also possible that the main sata ic got damaged or some smd capacitors got shorted.

Sometimes is just a short on the power rails that causes a board to malfunction or to not function at all and, apart from times when more things got damaged, usually fixing the short or the faulty components on the power rail puts everything to work again.

 

I don't know if you are used to work with electronics, if not I advise you to contact someone that can help you. Maybe indeed it is an easy fix, maybe only the diode is faulty but working with smd components sometimes can be tricky.

I guess that with all this info, if the problem relies in fact on the power rails, anyone skilled with basic smd soldering and electronics knowledge could replace the diode and maybe some other faulty component along the way while performing tests for any shorts on the board.

[Lorise]

It sounds like you've run into a common mishap with electronics. If you've connected a higher voltage power supply (24V) to your SATA Hat, which typically expects a lower voltage, it's indeed possible that the diode or another component has been damaged.

Steps to Repair the SATA Hat:

Identify the Component: First, ensure that the component you suspect is damaged is actually a diode. You can refer to the schematic of your SATA Hat if available. The diode's orientation is crucial; it generally allows current to flow in one direction, marked by a line on one end indicating the cathode (negative side).

Diode Replacement: If the diode is damaged, you'll need to replace it. When soldering a new diode, make sure it's oriented correctly – the line on the diode should match the line on the PCB footprint.

Checking Other Components: Besides the diode, check other nearby components like capacitors, resistors, and particularly any voltage regulators. These components can also be damaged due to over-voltage.

Testing the Board: After replacing the diode and checking other components, test the board with the correct voltage supply. It's good to use a multimeter to check for shorts or open circuits before powering up.

Further Diagnostics: If replacing the diode and ensuring no other components are visibly damaged doesn't resolve the issue, you might need to delve deeper. Check for any burnt traces on the board or components that might not show visible damage but could be faulty.

Additional Resources:

For replacement components like diodes, and to get a better understanding of suitable specifications, check out SMF12A product page. This might help you find a suitable replacement with the correct voltage and current ratings.

Remember, always double-check the power requirements of your devices before connecting them to a power source to prevent such incidents in the future. If you’re not sure about the repair process or the diagnostic steps, it might be helpful to consult with a fellow electronics engineer or a professional repair service.

Cheers and good luck with your repair!