Yihua 936 heating element

Page 9 of this instruction manual:

Also the Hakko part number for the heating element may be "A1321", this apparently uses the same iron:

Probably not worth the trouble to get one though, especially compared to a new iron for $5.

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Thanks for that. It looks like the A1321 are the ones I need as the dimensions match.

Good to have that info as there seems to be plenty available online at reasonable cost.

Do you know of any real evidence for this? I'm just curious, I rarely order ICs from China on Ebay, but I'm thinking of getting some LM3914s at the moment.

I know about the fake chips that pop up with expensive audio transistors and the like.

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Yes, it happened to me.

I'm just curious, I

I ordered some MOSEL 6264 SRAM selling as new or NOS (can't remember which) but condition was listed as new.

The date code was 0832 which is not long before MOSEL shut up shop but the chips had definitely been desoldered with traces of solder still on the pins.

All the chips worked and I was happy with what I paid and would have paid that much for used chips anyway but when I contacted the seller I was given a further discount refunded to my account.

The seller promised to relist any subsequent chips as used but I don't think they were ever listed again.

Fake capacitors even, small ones housed inside large cans.

Interesting, thanks for sharing. There's surprisingly little I can find on the 'net about the specifics of all this.

As a rule I don't buy electrolytics off Ebay whatever the price due to "capacitor plague". Sounds like that's just the first reason to avoid them.

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[snipped]

Oh, really? I was going to ask. Patence isn't my strong suit. At that price I'm tempted to order another one or two (or three even) - why change tips when you can change irons? It's easier to change irons than tips - especially when they're hot. I'm doubly impatient because in the past when I've found good deals often they don't last long.

However I'd like to know that what I'm getting is going to work before I commit any more of my 'really needed elsewhere' money....

Cheers,

--
Shaun. 

"Humans will have advanced a long, long way when religious belief has a cozy  
little classification in the DSM*." 
David Melville (in r.a.s.f1) 
(*Diagnostic and Statistical Manual of Mental Disorders)

Great minds huh?

You should get yours before I get mine - can you please let me know what you think of it when you do? I'd appreciate it. I got an email on the 8th saying mine had been shipped.

Cheers,

--
Shaun. 

"Humans will have advanced a long, long way when religious belief has a cozy  
little classification in the DSM*." 
David Melville (in r.a.s.f1) 
(*Diagnostic and Statistical Manual of Mental Disorders)

Yeah no worries will do. Mine should be arriving this week.

OK, it arrived. Packaging was barely adequate, a plastic bag containing handle wrapped in bubble wrap inside a shipping bag.

Well the handle is very similar to the one that came with my station. The cord is about 90mm shorter, the grip is slightly different and the supplied tip is the same as what with my original handle. Useless IOW.

If anything it is slightly cheaper made then the original supplied one but there is nothing in it. The connector is the same, the cord is the same bar the length, the element looks to be interchangeable though it's PCB is identical in design but not the same manufacturer. It's somewhat easier to slide out of the handle which is a good thing as on the original it was a very tight fit and much tighter then it should have been.

Plugged it in and it heats up. Needed a bit of calibration as temp was off by a bit but otherwise OK.

Will use it for a while to see how it goes.

Let me know what you think when you get yours.

Well. I got mine today also and all of the above apply to mine (except I didn't get bubble wrap, just a black plastic bag, similar material to plastic rubbish bags).

The cord on mine is ~65cm (original on Yihua 852D+ rework station was ~85cm, I guess you could say 90cm including the bit that goes through the handle to the PCB).I find the new one to be a bit too short for how I've got my work area set up (but I can work with it). Also the cord is a bit stiffer than the cord on the original, the original's cord is quite supple.

The heating element that my original is fitted with isn't ceramic on the outside, it appears to have a metalic sheath over a ceramic element (the end is ceramic). This new one is bare ceramic, both are ~3.8mm diameter athough the new one has a 'burr' on the end that makes it a tight fit in some of my tips. However that's wearing off already so shouldn't be an ongoing issue. The PCBs are completely different with the old one looking to be much higher quality.

It's also cooler than the original at the same temperature setting, by

anything other than a rough guide so that shouldn't bother me either. I wouldn't have a clue as to how to calibrate it and if I did find a trimpot inside the case changing handles would throw it off each time anyway.

I've just gone ahead and ordered two more with a note to the seller "Can you please supply these two with the 90cm cable as per the listing as the last one I bought only has a 65cm cable." It's worth a try but I'll take them with the shorter cable if I have to. At that price they're a steal even if they're not quite as good as the original and even on my tight budget I managed to find the ~NZ$13.50 for a couple more.

Cheers and thanks for the OP as otherwise I wouldn't have known about these. :)

--
Shaun. 

"Humans will have advanced a long, long way when religious belief has a cozy  
little classification in the DSM*." 
David Melville (in r.a.s.f1) 
(*Diagnostic and Statistical Manual of Mental Disorders)

Yep, I guess I got lucky with the bubble wrap. You got yours in good time too.

Our original handles sound like they might be slightly different, mine had a ceramic element like the replacement does.

On my station the trimpot is accessible externally just under the main dial. I checked the temperature using the temp sensor on my multimeter and tweaked it. I don't have much faith in the indicated temperature either, it's just a rough guide.

Doesn't hurt to ask. You could always desolder the element and swap it I suppose.

No worries :-)

Yeah, I reckon they must have sent them on the same day. I got an email on the 8th saying it was shipped so that was only 6 days from then. I just got an email last night saying the others I ordered had been shipped. I wonder if they've got the full length cables I requested? I suppose there's always the feedback system if they haven't.

I haven't dug out the leaflet that came with mine but I'm wondering if it wasn't a 60w unit. That might help to explain the new one being cooler as it's 50w. I see there are 60w units on ebay for a buck or two more.

No such luck with mine.

Yep. Iron too hot turn it down. Not hot enough turn it up. ;)

Yeah. However I like the idea of not only having spares (especially at that price) but also being able to swap irons rather than swapping tips. The only reason that might be an issue now is I've kind of got used to where to set the dial for different jobs and solders and with an iron that runs cooler I'd have to use my brain (!) and factor that it.

Cheers,

--
Shaun. 

"Humans will have advanced a long, long way when religious belief has a cozy  
little classification in the DSM*." 
David Melville (in r.a.s.f1) 
(*Diagnostic and Statistical Manual of Mental Disorders)

For what it's worth, here are some notes on my Hakko 907 iron bought at about the start of the year. I don't remember exactly what I paid (this one seems to have escaped my "Ebay records"), but it might have been a bit more than $5.

All physical features noted about your newly purchased irons apply to my one, except the cord is a little more than 90cm. I remember that I specifically choose one seller with irons that had a different looking plug on them - manually installed instead of moulded onto the cable. As the price was about the same as the cheapest ones, I went with this because it might mean that I could keep the connector for easy re-use later (it won't stay on the iron because I'll be hooking that up to my Dick Smith soldering station).

I haven't got a soldering station intended to use these irons, but I couldn't resist powering up the element breifly while I had it disassembled. Clearly the element itself is towards the end, and about 1-2cm long, because this is the area that started glowing red hot, before it started smoking (I may not have been quite breif enough!).

Also notable is that the tip does indeed have a ground connection. A somewhat ingenious spring that maintains contact with the barrel when the iron is assembled.

Heating element and thermistor connections are made to pads on the outside of the narrow ceramic heating element, towards the bottom. The connecting high temperature insulated wires that then go to the PCB are soldered to these pads, but the solder joints look different to usual (more grainy) and I suspect a high temperature solder has been used. This may make replacement of the heating element more difficult - but I haven't tested desoldering the connections myself, and I may well be wrong.

The iron's PCB is simply provided to make connections between the high temperature wires going to the ceramic heating element / thermisotor assembly, and the wires from the cable.

Of note to those unfamiliar with these irons is that the tips are constructed with a long hollow section in their shaft that snugly fits the end of the ceramic heating element. This makes them incompatible with "Weller style" tips used in may irons marketed in Australia over the years. The tips themselves are also unable to be used in my Weller iron because the shaft is slightly wider than it can accommodate, I haven't checked with my other irons which all take Weller tips.

My iron is marked (in poorly printed Gold colour):

24V ESD HAKKO 907 50W SAFE

As noted previously in this thread, the thermistor is a PTC type with a value around 50R at room temperature.

Specifications are effectively provided in the User Manual page I referred to in my earlier posts.

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Well I got the other two at the end of last week - not bad, from ordering to delivery in less than 7 days! Unfortunately the cable length is the same on these as the first, not the 90cm that is specified in the listing. However I don't think it's worth the trouble to complain - the price was good and being a new ebay member I'm not sure how much weight a complaint would have or if it would result in anything positive.

That said the cable length is restrictive and I seriously doubt that I can find affordable (in this sense) five-core supple cable to replace it with a longer piece. Who would have thought that ~20cm would make that much difference.

--
Shaun. 

"Humans will have advanced a long, long way when religious belief has a cozy  
little classification in the DSM*." 
David Melville (in r.a.s.f1) 
(*Diagnostic and Statistical Manual of Mental Disorders)

Negative feedback has a lot of weight in Ebay, that's why most of the sellers usually plea in the listing to contact them about problems rather than leave bad feedback. Usually where I've had a problem I've been refunded almost no questions asked. That's with the dirt cheap stuff I buy though, might be different if you bought something worth "real" money.

If the stiff section was at the soldering station end, would it be all that noticeable?

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Ok, thanks.

I wasn't thinking of joining it, rather replacing it (as both ends have 'real' non-moulded connections). I don't like joins unless asolutely neccassary.

Cheers,

--
Shaun. 

"Humans will have advanced a long, long way when religious belief has a cozy  
little classification in the DSM*." 
David Melville (in r.a.s.f1) 
(*Diagnostic and Statistical Manual of Mental Disorders)