EEVblog #1171 - Yihau WEP SMD Rework Station Meltdown!

hi I thought we'd take a look at a complete fail in one of these a whip 898 D soldering stations this one actually I've been while soldering desoldering SMD rework station thing Oh a web is actually the gangs you yeehaw Corporation and you might have seen these actually branded as a yeehaw I believe it looks similar to the a-10 brand one that I actually did a review of her quite some time ago and that one actually had some real major faults in at which people talked about on the forum I didn't do a follow up video to that but I'm not sure I don't think a-10 are actually associated with WEP I think they are actually different maybe they rip off each other stuff I don't know anyway this is a games you yeehaw WEP station and it's actually belongs to David he's gonna tell us all about it here he is behind camera put your hand in there so they know you're real there we go and what this was your personal station tell us what happened yeah had it for years okay yeah yes this thing worked really well for years and then I I moved apartments and I started setting up my lab again I'd set up like this like a temporary bench it's covered in cardboard and all this stuff that you don't want near one of these when they go nuclear meltdown so so I've been I've been we're doing rework for like four hours just I'm methodically going through different combinations of resistors and capacitors just to find like an optimum pair right as I calculated a few things and I knew it within a certain range size are you doing what like and you can basically unless you want to take the pads off I figure hot air stations the only way to go I'm gonna put pressure on the pads no way you can put tweezers tweezers or a nice way to go but you gotta have a separate tool for that yeah I don't know the tweeze at all so it's the only way to go so I've been using this for like four hours and then I put it into its its holder here and there's a magnetic detector in here which normally turns it off and you know sometimes it was a bit buggy sometimes it would it wouldn't turn off and you just turn it round because the research is no other place so the switch is actually in here which has to go down the cord and the maintenance in the holder yeah I do believe I think there's a cut-off internally like in the handle but right anyway so what happened this time wasn't out at all the the the reefs which did trigger a turn the thing off but the heating element never turned off so when you have the hot air going past the the element it ends up cooling it so the device is you know it's designed it's just a lot more heat thermal flow regulation yeah yeah yeah well yeah well it has a stable zone and then once you stop the airflow the temperature just shoots through the roof so this got like red to white hot like right that guy bright I don't have a great memory of the things I wasn't I was only half looking at that suddenly it cut started blooming smoke and right trying to kill me and you were trying to hold it up and wobble and it was all going all wobbly yeah so this is in a carpeted room right on a cardboard fire desk basically and it started gotten to this like gel state plastic bulbs things are falling into my hands and I I'm trying to unplug it and get it like move outdoors because when this type of plastic goes it coats things in it yep yep my lungs anyway so yeah that that happened it was it was smoking for hours and yeah this is probably why you should invest in a good one of these not Weber like they've got a website they look sort of semi-professional if like you know Chinese menu design and manufacture but they you know from the website you might get a reasonable vibe from it but of course when you actually look and feel of this thing you know when you get it you know it's pretty cheap it's built down right so how much did this cost on eBay like 70 bucks 70 bucks and that included a soldering iron and the I just noticed this so during its a sold during pause it's important I have the pause in there I know notice that years right so and again it is down the bottom as well so how do you I would have assumed that this would have worked via the airflow shouldn't have mattered the there should be a temperature feedback a thermistor in head to measure the element temperature and you would think the element would be regulated but you think maybe it's not we don't know we haven't torn this thing down yet um you think that they may actually be that's not a vent is ever no no oh literally just molding oh he'll open did it before where's the fan then oh it's there on the other side one side is molding in one side oh really yeah it looks blocked to me I think it opens on the sides oh okay right oh yeah I think I can see it now yeah it goes through okay so it's got a little squirrel cage fan which sucks in the air and closed it out but so terribly mounted right so you think that you heard the fan go off when you put it on here and went off right but the element remained on yep kept getting hotter red hot Wow let that be a lesson well let's turn it and tear it down and see what's what all right let's take this apart and you can see how that's just like all melted in there like that and this rotates there's nothing to hold that in place there let's have a look David what do we got here there's our little squirrel cage fan and they've got the rubber baby buggy bumper on there which is slightly melted it's it's kind of I don't know no no I don't think so anyway they got it on there to vibration isolate it but then nothing to vibration isolate this end of it so that's a bit of a that's a bit of a fail and we've got our little boar down there there's nothing I like it's just a there it is there's a reed switch okay just a little like glass tubular Reed switch classic it's yet just some sort of like silicon holding that in that's no problem they've actually molded a spot into the case actually for that Jesus Patrick on here look at this ah spared no expense really spectacular spared no expense a little fan so the fans still connected maybe we could measure that but let's get this board out have a squiz that's how switch so what are we got in here Wow yep no there's no circuitry fun plus this piece of me is fun plus so this yeehuh wasn't fun for David's hot + hot - the red goes into hot - and the black goes into hot + geniuses absolute geniuses there subvert in our expectations that's what they do anyway we've got okay the earth is connected over to here so yeah that's you know me it's okay um and that's actually that's all hate shrink down and there it doesn't look like you know it's built down to a cost but it I don't see anything inherently bad in there no I don't see anything inherently bad so yeah what went wrong um I think the fan seized the all you think the spam oh you think that they maybe the detection didn't happen and the fan broke or so you stopped the vibration to me going thing right right but there's your temperature sensor so it does have temperature sensing inside here yeah so there's your element so that should have thermally regulated that even if the fan fail yeah and I cut off so why why didn't it do that that is that is weird it's not like it's just pumping you know power into this element unregulated and then relying on the fan to like you know at a constant airflow to keep the temperature it's actually got presumably that is a feedback on there so that's their they're like Teflon coated wires I can feel that they're not they're like that stiff insulation they hide high-temperature stuff as you'd need um so looks okay ish why did it fail hmm hold on to your hat oh we can pull this baby out look at that oh this is it I didn't know no it's some sort of fiber glossy sheet wow that's terrible Muriel Wow look at that sigh that's Repton layer upon layer of this stuff which is just wow look that's there okay probably should have worn gloves masks have to keep going now can you press the zoom out key came out and rock it back yet I oh my goodness Wow there we go anyway there's L so there's our element such Oh God Wow so we've got looks like a ceramic former in there and it's literally yep it just goes around there it's got you know nichrome resistance wire there's the other wire oh and then it goes through okay so the there's our there's our element there's our sense in can you zoom into that Dave David sorry hates being called Dave there it is there it is there's our little thermocouple right in the airflow pass so that's pretty good I don't you know that the location of that's alright so there's nothing inherently wrong in there at all this was the only way to clean it up well that really sucks I'm sure if you're gonna be able to see that but there's still all these little specks lifts like on my anti-static mat they this sparkle if you get the light at the right angle ah stuff is horrid alright so let's take this sucker apart and see what's what because obviously I'm like four at this stage it seems like something has like its failed to detect and maybe if just if the fan fails and you might think because you just put it back down like it could have been like the contact like the wire has come off now but of course we just sucked it into the vacuum cleaner so you know a little pissant little wire on there really could come off easily especially with Lee you know the vibration and everything that comes from this fan it's not exactly a solid you know it's not exactly a huge number of strands in that baby so that could be an issue so there you go that's like an eight strand or something like that but it is quite thin and it's just sort of you know it could have had some Nicks on it or something like that there's no strain relief on that there's no vibration relief it's not silicone down it's not gunked down or anything like that so I Rick and that's a fail right there because if the fan goes and it doesn't end the magnet which of course as David said it you often miss this as if it's not like oriented in the road is not rotationally oriented right then the magnet doesn't hit the arethe switch and doesn't always switch off so if the fan fails and it fails to switch off then that's probably what happened here I'd say rather then so it's probably you know like I may be a mechanical sort of fault perhaps now I'm just checking the earth in on this here because I'm the Aten one which is not related to this even though it looks very similar I believe it's not related anyway there we go you can see there that that is connected to mains earth it's a bit high but anyway it's there and I believe it was are connected to the neutral inside this one there we go now it's not physically connected earthing and mutual are not joined as they shouldn't be because we use the multiple earth mutual system here it's tied they're shorted back together but not in the product back at the the power distribution point all right let's have a look down here there we go we are input fused there you go well and we got standard cord clamp grommet there a little bit how are you doing down here on the transformer earthing but at least it's it's there so yeah they've just soldered that down it's not it's not properly crimped or anything like that wow it's pretty how you're doing but anyway I assume that goes up to clucker no it doesn't go directly up the clock er goes down to then this another tag down here which is also just not crimped or anything it's just got multiple stuff connected to the tag and then this note that goes over to the soldering iron one where's the earth going to it's that little pissant green one there so that tiny little that tiny little gauge wire is what's protecting the main element up here if the elements somehow shorts out to the case up there wow that's not great is it yeah you're really getting what you pay for here so yeah apart from that pretty standard implementation of a single sided arrangement we've got a micro in here so that's doing all the business what Samsung is that Samsung it's upside down so all the electrons are gonna fall out yep it's a Samsung well it's three F 90f presumably like a flash based microcontroller 94c four I'm gonna have to google that wow I didn't know Samsung we're in that business that's weird usually these things you you know one of those Paducah microcontrollers or one of the other you know like they're 10-cent micros or something like that or they might even use like an app mill or something like that it's a bit more upmarket but Wow and yep sure enough if you look at the data sheet for that it uses the same 88 chipset or whether like instruction set whatever that is it's a Samsung thing so there you go interesting so yeah the rest of this board doesn't there's still a lot of confidence in you but anyway like they're you know they've done a reasonable job they're actually gunking down the connectors so they don't come off shame they didn't do the same vibration treatment up in the handle where you actually needed it but down in here you know it's built down a price it's exactly what you'd expect so it is what it is just remove some of the water in there for those playing along at home want to see the trainee or is here maybe down in there perhaps but a couple of 10 turn trimmers in there a couple of op amps are they three five-eighths yep love all the through-hole resistors they've actually done a decent job to get such a layout with like the LED display and everything all on a single sided so yeah that's off to the PCB designer there that's it's not a trivial task there's the other part down in there that looks like a genuine St Joby they got the reckless at isolation slots there and over here optocoupler across there you know it's not too bad well there you go this is how desperate the PCB layout person got is that they had to put the the driver chip for the the multiplexer driver or Mayor's at an individual were micro not sure TW something Twi is it but anyway they had to put in a slight angle just so that they could sneak snake a few more traces out here in the vertical distance required that's a bit of a PCB designers trick there especially like if you see like especially on like video cards or other highly integrated and PC motherboards and stuff like that you chips at like a 45 degree angle that's like you know instill instead of the square chip in like that you'll see it like that at a 45-degree angle because then you can get the traces out from one side and the other like that it's just easier to round out the traces that way so they went by gorillas don't have the hide in there what are these bloody industrial design has done to me they're screwed me over because I have only given me this X amount of board space throughout this thing on and they want me to do it on a single sided board to save the extra you know ten cents or whatever on the bomb cost for this thing so I can't fit it even though there is quite a bit of still some extra room down there to route some traces anyway they decided you know just go tilt that chippy a little bit and you can get a couple extra traces out nice anyway so there's wave soldered that obviously and they just didn't bother to have another sort of mass between pin rubbish over here they're just happy to waste solder all that and you know it's okay I think the board's they've done a half a reasonable job don't even look at the brains of the caps don't even ask jec what shouldn't have even looked you know I don't think that there's anything inherently wrong with this apart from the fact that well it could be everything to do with this it could actually be an algorithm fail on the part of this because I think ultimately I believe what's happened here as I said before I think the fan failed in some respect Eva may be the driver for the fan could have failed so it could be an electronic thing or maybe one that liked it one of the connections that could have broken internally or something like that I'll actually measure that fan here yep there you go I just measured it the fans actually open circuit so the coils Gonski in that so that's probably what happened to just eventually burnt out I don't know you know how it's a Shinzon market fan and it's not that great and it eventually booked it and burnt our cursor David did use this for like like three years it was his main user I and so it did actually work you know main you some desoldering they're very workstation so it did get a lot of use and it just eventually burnt out when that burnt out even though this has a temperature sensor in it which should thermally regulate this it maybe it didn't do the job wasn't enough maybe it just couldn't compensate but it should have like detected that and just shut it off it could have done that in software so there's really no reason when you have a thermocouple control feedback loop in here to regulate the temperature there's no reason that that micro couldn't have detected the fan fail and the temperature would increase of course would start increasing them to have to back off on the regulation supplying the power to the element and all that but it could have been able to detect that and eventually shut it off so I'm going to say that that's probably what happened is a mechanical fire inside the coil of the fan and combined with maybe some dodgy software in it caused or that issue that's that's probably the best explanation I can come up with so we're just following the money here just this is your mains input wire so it comes here it turns from blue into black thanks for that it's and some blue into black and this goes over to the board here so they're terminating the 240 volts into the board and then the other side and then the primary of the transformer plugs in here as well I'm not sure which ones what doesn't matter and then then the element for the heater which makes sense the heater for the hot air gun because the holy gun consumes more power than the soldering iron it requires larger amount of power so that is switched in there and switched with that has got to be a triac so we're just checking that it wasn't 240 volts directly across the element and they were using the fan as regulation to regulate the temperature that would be bags in if the fan fails then there's no feedback to control but you still be able to sense it and cut it off but anyway yeah it looks like there that's got to be a triac I'll look that up and so yeah it looks like they should have had the ability in the software to actually you know to sense that and regulate that and cut it off by the way if you're wondering about the fuse rating six amps here the primary sure enough if you can see that it is a six amp job' so that's 1440 watts or as this hot-air gun is rated at 750 watts in the iron's not much it's like 50 watts or something so really the fuse is double the rating of the the element power rating of the hot-air gun yeah woopsie cuz that obviously didn't blow oops there you go that's the whip what is it I don't know eight nine eight D plus I probably wouldn't recommend this thing I'm even though it's gone oh nice though certified holographic sticker on there that it's like a genuine whip thing and you know they look like they're a reasonable maker if you visit their website you know you might get a bit of confidence but obviously these things are built down to a price they haven't got the compliant CE Marking on there anyway and they saw during station yeah I really wouldn't recommend these I mean if if you've only got the 50 or 60 bucks you know they're gonna work I mean David was quite happy with it like the actual performance of this thing with the soldering iron and the reflow hot air as well so you know it it works but yeah you get what you pay for anyway let us know if you've had an issue like this but yeah genuine meltdown which you could have went a lot worse than what it did you know if David wasn't there do I save it just let the Weller thing hmm anyway if you had any issues with these are of the whip products let us know in the comments down below over on the eevblog forum hope you enjoyed it catch you next time [Music]

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Views: 159,420

Rating: 4.6090312 out of 5

Keywords: eevblog, video, yihau, soldering station, smd rework station, yihau 898d, fault, meltdown, surface mount rework, surface mount soldering, hot air station, surface mount, hot air gun, solder station, hot air rework station, yihua soldering station

Id: tUFW5teeRBM

Length: 24min 34sec (1474 seconds)

Published: Wed Jan 23 2019