• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Need help identifying a circuit board

Status
Not open for further replies.

Pommie

Well-Known Member
Most Helpful Member
I'm guessing that you connected power the wrong way around. If so (and if you're very lucky) then the diode on the left (D9) may have acted as a fuse and may be the only part that needs replacing.

Mike.
 

kaysadeya

New Member
Thanks Mike. Yes the D9 is crispy, but so is the round diode on the right (R1, I think).

What I think caused this that I wired the RS485 (the wires that control the PTZ features) incorrectly.
 

Pommie

Well-Known Member
Most Helpful Member
If you can identify all the parts it would be trivial to replace them all. Certainly easier than getting a replacement board.

Mike.
 

DerStrom8

Super Moderator
Most Helpful Member
Considering the way D9 is connected (one side connected to a fat trace, one connected to what I expect is the ground plane) chances are it's a unidirectional transient voltage suppression diode. If you connected power backwards it would behave as a forward-biased diode with ~0.7V Vf and would fry. I would pop it off the board (desolder the best you can) and measure across the pads with an ohm-meter. If the ohms are significantly low, then you probably have other problems as well. Otherwise you're probably fine. Theoretically if the rest of the board is not damaged, removing this diode would allow it to work again, albeit without transient protection. You could replace the diode with one that has a standoff voltage equal to or slightly greater than the supply voltage. For example this camera appears to run off of 12 volts. Replace the diode with a 12-15V unidirectional TVS diode (Looks like it may be an SMB/DO-214AA or an SMC/DO-214AB package - you'll have to measure to be sure).

SMB version: https://www.digikey.com/product-detail/en/bourns-inc/SMBJ12A/SMBJ12ABCT-ND/2254268
SMC version: https://www.digikey.com/product-detail/en/bourns-inc/SMCJ12A/SMCJ12ABCT-ND/2254118
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top