Paul C. Buff Vagabond II 300W sine wave inverter teardown... PCB of shame  - Page 1
Forum section: electronics / general

author: turbo!
author_rank: Regular Contributor
timestamp: January 10, 2014, 04:08:12 am
content: This was purchased used and board revision seems to indicate it was built in 2008. Paul C. Buff Inc describes itself as a manufacturer of strobe and power inverters intended for strobes and marketed towards "professional photographers". Vagabond II is a current limiting sine wave inverter with a continuous output of about 300W with a self-contained battery charger. It has two modes, slow and fast which is spoken in terms of strobe recycle time and the two modes have a different current limit.To my hands, the case has a solid feeling aluminum. The plastic bezel is a bit cheesy. Inside? It's one of the worst quality PCB I have seen. I've seen seen many one time use test boards that look better than this. A lot of corrosion from unwashed flux and it is obvious it is not from hostile environment as there is no signs of chemical attack on any part of the case or terminals. Mediocre soldering and WTF mounting of spare resistors to make a larger value resistor. There's a logo and a name "New Power" on one of the boards. I have no clue about that company. While this model is no longer offered by the manufacturer, I am surprised something this quality got through from a company who markets to professional users. For some reason, power inverter boards are rather built sloppy and messy compared to high tech stuff, but I've not seen one with this level of sloppiness and this is including $9.99 ones cigarette lighter stubby you see for sale every once in a while. At first, I've wondered why it smells like hot PVC and melting solder with a very generous looking case. Once inside the case you'll see that heat sinks are quite small. (sorry forgot to take pics with them on).Many solder joints were in blobs of inconsistent size. Component leads were trimmed in such a way on the bottom that they're very close to touching adjacent points if they were to get touched. There are some solder whiskers and pieces of trimmed leads stuck on the board. The wires on left side board crams up against the top of components once assembled into the aluminum case. Multiple identical connectors are used between totally different components and if you don't keep track of what you plugged and unplugged, you can't easily figure out what plugs in where.On the outside, it looks like this with a nice looking case. The product is shipped with a 12v 17 or 18Ah ish lead acid (SLA) in a bag that will fit it all. It is intended to power large professional line voltage strobes. It is essentially a sine wave inverter that limits current so that it doesn't trip during capacitor charge up. (this pic is from the web)Top view:Left is your average CC/CV SLA charger board that's wired in parallel to the inverter board on right. The quality is noticeably worse on the inverter board.Bottom view:You've got to be kidding meNew Power. WTF IC?Severe flux corrosion:

author: amyk
author_rank: Super Contributor
timestamp: January 10, 2014, 11:09:47 am
content: That's not corrosion, it's residue.

author: con-f-use
author_rank: Unknown
timestamp: January 10, 2014, 12:04:07 pm
content: That looks atrocious.

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 11, 2014, 04:48:03 pm
content: Is there a point to using "slow" mode? And while the current limiting would work nicely for resistive loads and linear power supplies without logic, switching power supplies, some motors (unless it does V/Hz scaling), and some devices with logic will not like it very much.

author: AG6QR
author_rank: Frequent Contributor
timestamp: January 11, 2014, 05:48:48 pm
content: Quote from: NiHaoMike on January 11, 2014, 04:48:03 pmAlthough the inverter can power many kinds of devices, this inverter is primarily designed to power photographic flash units (especially the Paul C. Buff line of flash units). You can think of them as devices that charge a capacitor as fast as possible from the mains. After the flash fires, the quick recharge of the capacitor temporarily draws huge currents.The "slow" mode limits the current, allowing the voltage to sag, reducing the losses in the wiring, ultimately allowing the batteries to last longer. The tradeoff is that the flash takes longer to recycle, so the photographer has to wait longer between shots, but he gets more shots out of his battery. Slow mode may temporarily drop the voltage well below the nominal 120V, which some types of devices won't like at all. But flash units don't normally mind.

author: Codemonkey
author_rank: Regular Contributor
timestamp: January 11, 2014, 06:23:10 pm
content: The stuff in the last PIC is just the residue from the flux cleaner after the board was wave soldered. Not really a problem. As for the other production time mods, well I've seen far worse in my time!

author: peter.mitchell
author_rank: Super Contributor
timestamp: January 13, 2014, 06:47:11 am
content: Quote from: Codemonkey on January 11, 2014, 06:23:10 pmIn the second last pic there is a DIP-8 in the bottom right, that looks like it may have some corrosion under the residue/flux.

author: bookaboo
author_rank: Frequent Contributor
timestamp: January 13, 2014, 07:17:57 am
content: That's the standard for cheap inverters. I've actually seen much much worse. You are lucky if even the most basic isolation standards are met. I get loads of these in for repair all the time, most are not even worth opening as they are built down to the penny.Obviously all are china imports. Contrary to popular opinion you can get reasonably well built inverters in China, but my buddy who imports wholesale tells me the cheap type outsell the quality type by 10-1 despite only a 30% price difference to the end user.

author: DaveW
author_rank: Frequent Contributor
timestamp: January 13, 2014, 01:18:58 pm
content: Bah, that's nothing,http://ludens.cl/Electron/chinverter/chinverter.html

author: turbo!
author_rank: Regular Contributor
timestamp: January 14, 2014, 03:30:06 am
content: Quote from: bookaboo on January 13, 2014, 07:17:57 amDid you see the quality of solder joints? Some are clearly porous. I found bits of lead clippings stuck to board too. This is not meant to be a cheap inverter, but a "professional quality" that sold for $300 or so for the whole kit.

author: bookaboo
author_rank: Frequent Contributor
timestamp: January 14, 2014, 08:55:10 am
content: Sorry I missed where someone mentioned $300, that's just crazy for a 300w. Here the cheap ones sell retail for £60 (~$90) and the half decent units are £90 (~$135).If someone has paid $300 for a 300w of that quality then they've just been subjected to a 1000% markup on a piece of crap.

author: amyk
author_rank: Super Contributor
timestamp: January 14, 2014, 10:15:53 am
content: Have you tested to see if it's really 300W? A lot of them exaggerate their output ratings by as much as 10xQuoteAnd that particular company appears to havespent the R&D budgeton a modeling agency instead... (that last link is pure LOL)

author: turbo!
author_rank: Regular Contributor
timestamp: January 16, 2014, 08:39:43 am
content: Quote from: bookaboo on January 14, 2014, 08:55:10 amDo a completed search on eBay and you'll find that used ones still fetch ~$200 USD. You don't realize how terrible the quality is until you open it up.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: January 16, 2014, 03:11:06 pm
content: Quote from: amyk on January 14, 2014, 10:15:53 amThe models look so out of place it borders on strange. The clothes don't help matters either. Let alone the choice of staging. Hey what looks good with power electronics? I know, a wet sandy beach and some models.Sent from my EVO using Tapatalk

author: amyk
author_rank: Super Contributor
timestamp: January 17, 2014, 11:37:57 am
content: Quote from: PedroDaGr8 on January 16, 2014, 03:11:06 pm

author: nctnico
author_rank: Super Contributor
timestamp: January 18, 2014, 05:34:41 pm
content: That lady must have been laughing here ass off afterwards. It's earning easy money posing next to some LoFi crap.

author: turbo!
author_rank: Regular Contributor
timestamp: March 05, 2014, 03:14:36 am
content: Quote from: nctnico on January 18, 2014, 05:34:41 pmMine didn't need any salt water help to corrode.

author: calexanian
author_rank: Super Contributor
timestamp: March 06, 2014, 05:46:20 am
content: At least its double sided and solder masked! For some reason the fact that the thing says it has a GFI in it just kinda don't sit right with me for some reason. Anybody else get that same feeling?

author: Refrigerator
author_rank: Super Contributor
timestamp: March 09, 2014, 10:18:09 am
content: Imo, that piece of sh...... i mean equipment you have must've been used in some photo sessions on the beach, hence the corrosion.