Hi,
I blew up a diode the other day. Looking to replace it, I cannot identify it. Can someone here help? I've looked and looked. The power involved is 24v..
429
UE
The circuit board has a K next to the part I guess that indicates polarity, perhaps it also gives a clue about what type of Diode it is?
Possibly a TVS Diode? It looks like it goes between chassis ground, some how 24v is involved, it is in the 24v area of the board found by probing around.
You need to reverse engineer the PCB foil circuit and show the diode’s connections to other components; this way we get some reasonable information.
This is diode number D89... next to cap C169...
I think I would be better off finding another diode just like it on the board for reference.
If so, can the diode be measured in-circuit? For some reason it is really really hard to remove components from the PCB. Had to reattach some SMD Caps and I got maybe 1 second before all the heat dissipates and solder solidifies again.. the heat spreads out... goes away.. so weird.
I guess you can get an accurate measurement with a multimeter..
It looks like the company logo is "Diodes Incorporated" .. How unique.
5 minutes tracing out the PCB (then drawing a schematic of that area) should give us the information necessary to help you.
Hi,
What equipment/board is this diode on?
What did you do? Is it difficult to take a photo and upload it here?
Picture attached. Sorry, my bad for not including it the first time.
This is a proprietary back board for a pluggable computer. The backboard is about 2 feet x 2 feet.
It has 3.3v, 5v, 12v, even 24v.
Once I heard the pop, the PSU turned off. It stunk up the house but showed no physical damage. I narrowed in on the area by doing a smell test. Once I smelled burned stuff, I went in with a multimeter checking the biggest things first. When this diode blew it closed the circuit making a direct short. Cutting it apart made the power flow again.. Now, I want to replace it.
What did I do? ha
Well, this is a mismash of parts, a project taken over from someone else. Things do not exactly line up as they should. They use PCI Express connectors to mate the CPU with the backboard. So, I ordered some PCI Extension cables to give some play and make things line up.
The problem is, and I did not notice this until after, that the extension cables are not 100% pin to pin pass through. The extension has some pins merged together. Which is probably just fine for real PCIE purposes, but this is not PCIE, merely the connectors. So, the merged pins caused some power to feedback and blew what I think is a TVS diode for an unrelated port. There are tons of TVS diodes on here, I assume this one blew first casing a short circuit, shutting off power, saving the rest of the board.
Think I found some real 1:1 passthrough PCIe extension cables today... Hard to tell with stock pictures.
Does the device work? If you have absolutely no documentation, it's probably better to just remove the diode and not replace it, if it works that way.
If the whole house stunk I'd be surprised if it was just the one diode, but maybe you got lucky.
Uhhhh! Diodes and all solid state devices to not die in a shorted condition!
Maybe it's a small house. Just saying.
hahaha ok ok it wasn't the whole house, but the immediate area.
I was wondering that too. Assuming the overload condition that caused it in the first place has been cleared.. It seems to run OK now, without it.
I sent an email to Diodes Incorporated to see if they will tell me
The device fuse is TOO large!
Good point. It is a backboard, used to distribute power and signals where they need to go, but yeah, they should have fused the components that use power along the way...
Maybe a design decision to not do it...
Then you found the "fuse"!
Are you using the exact same power supply as the original manufacturer? How do you know that you are following all the specs for the board?
I doubt very much that Diodes Incorporated will want to weigh in on an almost completely unknown failure on an almost completely unknown board... your words, a "mismash of parts".
