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Subject: Ungar 9900 Soldering Iron Base Station

Complaint: Dead

Diagnosis: Secondary on power transformer is open

Reason: Shit tier QA at factory didn't notice a wire strand bridged across the power transformer output.

Hard to believe they missed that, it's one of the strands from the power transformer's wire. I can't fix it as-is, it will need a replacement transformer or an external transformer. Can't use DC because this particular model uses a light dimmer-like circuit (Triac) to control the heater of the iron.

Subject: Ungar 9900 Soldering Iron Base Station Complaint: Dead Diagnosis: Secondary on power transformer is open Reason: Shit tier QA at factory didn't notice a wire strand bridged across the power transformer output. Hard to believe they missed that, it's one of the strands from the power transformer's wire. I can't fix it as-is, it will need a replacement transformer or an external transformer. Can't use DC because this particular model uses a light dimmer-like circuit (Triac) to control the heater of the iron.

(post is archived)

[–] • 3 pts

How long have you had this soldering station? Ungar has been gone for a long time now so this wasn't a recent product that failed quickly. Sure the condition could have been there for years and only recently became a problem if the strand moved and shorted the secondary winding. Perhaps the failure mode isn't caused directly by this. That's a pretty thin strand of wire and the secondary winding is likely a thinker gauge of wire than it is. Why would the secondary go open if this strand didn't burn through? This should have acted a bit like a fuse if it carried enough current to open up the secondary winding. There's probably more at play here.

Sad to see an Ungar die. I loved that brand and I still have a UTC-290 station from the mid 80s in working condition. I also used to have a 9900 that was rebranded under the Tenma/MCM Electronics brand in the 90s, but that one got left behind at a job by accident. I would try to repair this one since they are rare and special now. Parts will be hard to find, but restoring this vintage unit would be great. I don't like modern stations and will stick with my Ungar as long as I can. I'll eventually have to move on, but I'll worry about that when I get there.

Anyway, sorry for your loss. Try to fix it if you can get a replacement transformer, if only for the preservation of history and such.

[–] • 2 pts (edited )

It's actually a customer unit, but it's mine now because they didn't want it.

As far as I know, this hasn't worked for years. I have no idea why the secondary burnt before this little piece of wire did, as it's a 2A transformer. Looks like an old oil burner power transformer, which is what it probably started life as, and was repurposed by Ungar. Could have been the transformer was defective from the start and this did it in. All I know is the secondary is now open and this piece of wire was there.

I'm planning on trying to find a transformer at the next show I go to, maybe I'll even get lucky and find an old lighting transformer that's high current AC. The tip is seized in the sleeve, but that should be just a matter of soaking it in some blaster and getting it free.

(I also don't know if there was more wire here at one point and it fell off as it burnt away. The joint isn't in the best of shape to start with.)

[–] • 2 pts

The tip is seized in the sleeve, but that should be just a matter of soaking it in some blaster and getting it free.

Word of caution on the tip removal (no jew joke intended). The tip has a "D" shaped shaft that goes down into the sleeve and makes contact with a fragile ceramic heating element. The element is about an inch long and just a couple of millimeters thick so it isn't very resilient. These heating elements are nearly impossible to get hold of these days, so treat it delicately if you remove it. Also might want to clean the PB Blaster off of it before heating it up should you get the unit running again.

[–] • 3 pts

(no jew joke intended)

And yet I laughed

[–] • 1 pt

The sleeve and the tip on this one come off as one piece from the heater assembly, that's what I'm going to soak. https://pic8.co/sh/XeWhia.jpg

[–] [deleted] • 1 pt

Well you could always rewind the transformer. I've done that a few times for various tube amps. But those are generally pretty big transformers.

[–] • 1 pt

24VAC transformers should be easy to get, they're essentially furnace power transformers. I don't mind making a wall wart to run the thing.

[–] • 2 pts

Well there's your problem

[–] • 1 pt

shit soldering on a soldering iron base

Thanks chinks.

[–] • 1 pt

This one was made in the USA. Sad, isn't it?

[–] • 2 pts

ugh thanks spics

[–] • 1 pt

They were in CA, so probably.

[–] • 1 pt

I can work on most things but I am clueless with electronics. I can rewire speakers or lights, but a board like this just makes so sense to me. It amazes me how you can look at this and talk like it's common sense. I hate not knowing things.

Good for you. I'm glad I got to read through this post.

[–] • 0 pt

It's like anything else. Part of it is knowing what you're looking at (as far as the board, components, etc.) and part of it is just having done it for a while. There are certain things you check, i.e. does the thing have power? No? Whatever powers it is a good place to start.

If you're interested in basic electronics, there's more information out there than you can digest in a lifetime. Just jump in.

[–] [deleted] • 1 pt

Oh, that's nice. Hopefully you've gotten lucky already and found a part number stamped somewhere on the transformer and a replacement.

Last thing that went up in smoke right out of the box on me was due to a big fat solder blob just sitting right in the mix of lots of very conductive things.

[–] • 1 pt (edited )

Have you got a pic of the whole unit? We might have seen the transformer in something else but yes, it should be fixable.

QA is always a bit human-variable, that's why it should be automated whenever possible, and they couldn't have done a HV test in that part of the circuit to identify it

[–] • 0 pt

It can be fixed, but the chances of finding a transformer for a 30+ year old device like this is slim to none, unless it's harvested from another unit. It's not really worth trying to do that since other parts, like tips and heating elements aren't readily available either.

I plan on cobbling together a 24VAC transformer from some stuff here at the house to make it work, and use it for as long as it lasts. Beyond that, cheaper just to get a new Hakko unit with supplies.

[–] • 1 pt

Magic smoke release enabled.

[–] • 0 pt

Yes. It's all gone too.

[–] • 1 pt

Damn, that magic smoke is what makes things work.

[–] • 1 pt

That's just a cheap resistor.