Watchguard Firebox x750e Firewall - Help identifying an inductor? - Page 1
Forum section: electronics / repair

author: d1wepn
author_rank: Newbie
timestamp: February 13, 2015, 05:24:18 am
content: Hey all, I hope someone might be able to point me in the right direction. This picture is taken of what i suspect to be the faulty component.I can tell that it is a 4.7uH inductor but having trouble identifying other specs like amp rating, tolerance percentage rating and what type. (SMD, High Frequency etc)I have tried searching google and some other forums but no luck yet.Is it important that it is replaced with the exact same specs or will a "close enough" 4.7uH inductor do the job?If anyone has any ideas or suggestions I would be very grateful.EDIT: Added some more photos

author: Monkeh
author_rank: Super Contributor
timestamp: February 13, 2015, 05:51:15 am
content: What makes you suspect it?For a replacement, something the same size will generally do. Measure it and I'll point a few out.

author: bktemp
author_rank: Super Contributor
timestamp: February 13, 2015, 06:22:58 am
content: Looks like Vishay IHLP series:http://www.vishay.com/inductors/power-inductors/

author: d1wepn
author_rank: Newbie
timestamp: February 13, 2015, 09:09:36 am
content: Quote from: evb149 on February 13, 2015, 06:05:23 am

author: d1wepn
author_rank: Newbie
timestamp: February 13, 2015, 09:28:36 am
content: added some more photos. thanks for the replies! i will measure it and get back to you all soon.unless anyone else knows the model off hand?

author: d1wepn
author_rank: Newbie
timestamp: February 17, 2015, 01:06:39 am
content: OK. I have removed the component from the board and measured it with a micrometer. It appears to be 6.7 x 6.7 x 3.1. It was a cheap micrometer but should be accurate within .1 of a mm. Also I have confirmed that it is a single coil inductor. Does anyone have any suggestions?I was thinking something like this one should be close.http://au.element14.com/vishay/ihlp2525czer4r7m8a/inductor-shielded-4-7uh-20-5-6a/dp/2467177

author: Monkeh
author_rank: Super Contributor
timestamp: February 17, 2015, 01:09:18 am
content: If you've confirmed it is indeed open circuit or otherwise damaged, that looks to be an exact replacement.

author: d1wepn
author_rank: Newbie
timestamp: February 17, 2015, 01:19:15 am
content: Quote from: Monkeh on February 17, 2015, 01:09:18 amI haven't actually checked but it was heavily damaged. As it was removed from the board it practically fell apart. Top fell off and all internals were burnt out completely.Thanks to everyone that helped me with this. I will let you all know how I go once it arrives and I have tested it out.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 17, 2015, 01:34:57 am
content: Yeah, looks like it's shit itself, at least somewhat...Replacement is a good idea, because that type of inductor suffers from thermal aging; it's made of resin-bonded metal powder, which works great (the particles don't touch so eddy currents are small) until the resin starts to break down (a temperature thing). As that happens, the particles begin to touch, and losses start going up... so temperature starts going up more... and so on.But, a better question is, why did it shit itself? Too much current?I'm guessing it's supplying the memory DIMMs there; have you checked the memory is still good? The transistors, are they blown? How about the controller driving them?What caused it? Is the power supply OK (did it fart out transients or something that caused damage elsewhere too)?I suppose replacing the inductor and checking nearby components is cheap enough to try, but do entertain the possibility of locating a replacement board altogether.Tim

author: d1wepn
author_rank: Newbie
timestamp: February 17, 2015, 02:01:15 am
content: Hi Tim. Yeah I sort of explained in post 4."The full story is that I attempted to install a new cpu into the motherboard. it was the correct socket and chipset but must have had compatibility issues elsewhere. as soon as i tried booting after the new cpu install, there was a large amount of smoke coming from that inductor. of course i switched it off but the damage had been done. I have also inspected the rest of the board and cannot identify any other damaged components. No discoloration or charring anywhere on the pcb or components."Even with the damaged component. The board still powers on and all LEDs on the board work but doesn't seem to pass POST. So yeah, hoping this might just do the trick.

author: Wilksey
author_rank: Super Contributor
timestamp: February 17, 2015, 02:09:06 am
content: Looks like L9 is the same on the other side, with those 2 N channel FETs in between. Is there a SM PSU chip nearby, you could check the rating of the app note for that.If it is in line with the FETs then you can check the characteristics from the datasheet (http://www.digchip.com/datasheets/parts/datasheet/161/FDD6670A-pdf.php)Possibly a 2.5A or something perhaps.

author: amyk
author_rank: Super Contributor
timestamp: February 17, 2015, 02:46:49 am
content: That might be part of the CPU VRM, in which case upgrading the CPU with a more powerful one that draws more current could cause it to fail.

author: d1wepn
author_rank: Newbie
timestamp: February 17, 2015, 03:01:28 am
content: Quote from: amyk on February 17, 2015, 02:46:49 amThis was also my logic.