# Racing Drone Flight Controller - Trying to "ID" fried SMD component

#### Strata

##### New Member
Hi Everyone, I have a SMD component I'm trying to ID so I can repair my F3 flight controller. Markings are "CA" with a (polarized line?), I thought it was a Case "A" polarized tantalum black chip capacitor 16 Volt but the length of those caps are 3.2mm long and this one I fried is around or under 2mm.

I contacted the company and they told me it's a resistor......I've never seen a resistor that's looks like this.

In the pic, the fried component is the exact same as the one next to it.

Thanks,
Strata

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#### JimB

##### Super Moderator
It looks like a diode, the white bar at one end indicating the cathode.

Looking at this database:
The most likely candidate is a ZMV829B varicap diode.

Whether a varicap diode makes sense in that part of the circuit, I do not know, but they are sometimes found in series connected pairs, as shown in your picture.

Another thing to consider is, what caused it to overheat like that?
Varicap diodes are usually found in low power areas of circuitry, most unlikely to overheat like that.

So, whether it really is a varicap, I am not sure.

JimB

#### Strata

##### New Member
Cool Jim thanks a bunch!!!! Its was a short circuit caused by me, in a rush to fly cuz sun was going down and forgot to inspect for solder splatter...... After I fried that component I was able to power up the board through a USB port we have on them but it wouldn't power up from the Lipo flight battery.

Here some pics of the board and how we wire them up if anybody is interested.

(From one of these pics you can see another pair of those components also on the board)

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#### rjenkinsgb

##### Active Member
Looking at the boards I'd guess they are just rectifier diodes for power routing, depending on what power source is in use.
I've found a schottky diode listed in one SMB codebook that has the CA marking.

Ideally you need to test an undamaged "CA" device with a multimeter to confirm it is a diode & see what the forward voltage drop is.

#### Strata

##### New Member
Thanks RJ I'll try to do that......... Power routing seems correct from the symptoms I saw.

Looks like it's a Zetex or Diode Incorporated ZMV829BTA https://media.digikey.com/pdf/Data Sheets/Zetex PDFs/830 Series.pdf

Having issues finding one, problem is it seems to be obsolete and out of stock. No luck on Ebay either ............Anybody have any tips on locating these components???

#### Strata

##### New Member
Waiting for reply from Utsource....... I was led there buy this website https://www.digchip.com

Here is what digchip.com pulled up......

Find supplier - Request For Quote
Search disributor results found for: ZMV829B
Select the checkbox items you want to buy or to ask for price then click on this button => Quote

Part number
DistributorStockDCManufactureDescription
ZMV829B
Online Chips
30000 - . .
Hxd Electronics Co.
621853 12 - -
Utsource Inc.
45000 07 ZETEX SOD323
Digtial Ic Limited(hk)
4001242 14191424/BT/11 KYOCERA SOP24/TO3-8/SOT-223
Depu Electronics Co., Ltd
38600 1550 ZETEX SOD-323
New Strength Electronic
2900 07 ZETEX SOD-323​
ZMV829BTA
Hxd Electronics Co.
621853 12 ZTX SOD-323
Premier Components
8305 13 Diodes/Zetex -
New Strength Electronic
2900 07 ZETEX SOD-323
Utsource Inc.
512 6 ZETEX SOD-323
Leading(hk) Ic Distributor Lim
9680 2016 ZETEX SOD-323
Centerchip Technology Co,.ltd
1375 - ZETEX SOD-323
Direct Components Inc.
9615 12 Diodes/Zetex SC-76, SOD-323
Digtial Ic Limited(hk)
34121 11/12/13 ZETEX SOD-323/SOD323
Depu Electronics Co., Ltd
2960 07 ZETEX SOD-323
Ocean Int,l Trading Co
8000 2011 ZETEX stock
Online Chips
30000 - ZETEX SOD-323​
ZMV829BTA(3K/RL)D/C96
Sunnlyic S.p.a.
12580 2007 - ZTX
Hxd Electronics Co.
621853 12 - -
Online Chips
30000 - ZETEX .​
ZMV829BTC
Hxd Electronics Co.
621853 12 - -
New Strength Electronic Co.,li
10000 - Diodes Incorporated -
Direct Components Inc.
9615 12 Diodes/Zetex SC-76, SOD-323
Premier Components
8257 13 Diodes/Zetex -​

Last edited:

#### JimB

##### Super Moderator
I've found a schottky diode listed in one SMB codebook that has the CA marking.
Looking at the damage to the diode, I think that it is more likely to be a Schottky diode in a power circuit than a varicap diode in a high frequency circuit.

Looks like it's a Zetex or Diode Incorporated ZMV829B
Er no.
Although that was my initial wild guess, I am more inclined to agree with rjenkinsgb that this is a schottky diode. I suggest that you do not pursue the ZMV829B as that is a varicap diode. A completely different animal.

I've found a schottky diode listed in one SMB codebook that has the CA marking.
What was the part number of that diode?

JimB

#### rjenkinsgb

##### Active Member
The one I found was SD883-02, a 20V 3A schottky.

It appears that part is made by multiple different manufacturers; I've not found one with the exact same ID mark and orientation, but it could be a generic copy in those boards.

#### Strata

##### New Member
Thanks for clarification Jim i thought schottky was a manufacturer, lol......

Thanks RJ, much appreciated!!!

#### Pommie

##### Well-Known Member
Assuming it is a schottky diode then the nearest I could find that fits your dimensions (outline SOD323F - does this seem right?) is the PMEG1030EJ available from Farnel. This is only a 10V device - what voltages are used by the board?

Mike.

#### Pommie

##### Well-Known Member
The best one listed that can handle 24V (30V) is the PMEG3015EJ but that can only handle 1.5A. Is there anyway to measure the amps flowing?

BYW, from your picture it looks like a bigger diode could be fitted - maybe look for a 40V 3A diode in a slightly bigger package.

Mike.

#### Strata

##### New Member
I believe it's less than one amp to power up the board.....

And yes it does look like I could fit a bigger case size, I totally didn't think of that, my brain was stuck on finding exact match.

Thanks Mike

#### Strata

##### New Member
She's flying again. Thanks guys!!!.....

#### Pommie

##### Well-Known Member
Congratulations. What did you replace it with eventually?

Mike.

#### Strata

##### New Member
Hi Mike

I got the diode you found;

PMEG3015EJ,115
1727-3872-1-ND
DIODE SCHOTTKY 30V 1.5A SOD323F

Got three from "Digi-key" for $.45 each. Got them at my door in a few days for around$5 total. Cheaper shipping than Mouser...

Thanks Mike and Electro-tech-online and it's members, couldn't have done this on my own!!!!