ZD-915 Desoldering gun upgrade - overvoltage fix 

My solution... a resistor with value 100 ohm 5 watt in the red wire of the fan. Fan now runs smoothly on approx 5 volts Greetings Erik ;-)

THANK YOU. Dude this is a fantastic tutorial and the upgrade is 100% worth it. The buck converter you found fits so perfectly into the old spot it's like a match made in heaven. Super easy to swap in, no case modification or cutting, and worked with almost zero trouble shooting. Cannot thank you enough for taking all the guess work out of something like this. BTW, my unit seems to have an upgraded PSU; it's fully enclosed and looks exactly like what comes in the pro'skit station. Not sure how many versions of the ZD-915 there are but I'm very happy with the performance after this mod. P.S. my dad loves you C64 videos, over the years of taking care of him it's been a struggle to keep him interested in just about anything. But your restorations, upgrades, and general love for the system is a great walk down memory lane. Keep up the amazing work, I really cannot thank you enough

Like other people before, I must thank you for those tips. I found that buck converter for 2.30€ on Ali... One difference, I ended using still the factory resistors for the pump. It's a bit overkill to use a buck converter just for one fan instead of some transistor as shown in another video about improving that ZD-915, but it's a fine and easy way to go straight to a good result. To conclude, the pump's suction is now perfect, when I was earlier kinda disappointed.

Very noble of you to keep your schoolboy error in there!

I just got one of these the other day and I think the stock version works just fine. Thanks for this video now I know I will not be wasting time and money upgrading it.

Good information and good comparison. I have the same solder tool and it's an upgrade I'm interested in doing now. Thanks!

Thanks for this. I've had one of these stations for a couple of years & will do this upgrade. The fan has always been annoying, but lately it's been making a whirring noise so I'll probably have to replace that too.

I've installed the exact same buck converter in mine, and I'm now contemplating installing a mosfet to drive the pump.

Very good work ... Thank you from Portugal :)

It makes me feel better when I see you trying to test suction with the hose off. Did that when I first got mine. :S

My ZD-915 has 24V fan wired directly to the power supply (actually these 2 connectors on resistor PCB are used as input, and the single connector is used as output). The pump motor is labelled 6-24VDC, so it could easily work with 18VDC from the PSU, but it makes it really loud.

Thank you very much for the tip. I just finished upgrading my ZD-915 with a buck-regulator (I set it to 13 V for now). It definitely sucks better now than before and the fan (I also had the 12 V fan installed) is significantly more silent, even though I didn't cut away the grille. My motor had the correct polarity marking and I also installed the diode and three suppression capacitors in X/Y-connection on the motor.

Simply add a small 110 or 220 V fan depending on your mains voltage and you're done.

Is funny how you start every single sentence off with enthusiastic and varying normal tone in your voice with clear pronunciation then slowly turn it into a quiet, low and bass tone..

I have this same unit. I may bump it up to 14V eventually. It seems to do the job ok for now though. Sometimes I need to use my heat gun on really stubborn solder blobs though.

7:53 - I bet it's worse, seeing as the hose isn't plugged in. 😋

The ZD-8915 and 915 and the one u have there all use 24 Volt heater element. Mine has a 36volt fan no problem with overvoltage on my 8915. but the 18 volt to the heater bug me. know there are mods on psu easy done to get 23.5 .psu on all these stations are ZD-P150 V 2.0. 18 volt 12 A, at least what other confirm they have in those models with or without sleep "sensor" The fans have different rating on many, Same as mine had a 12 V fan while mine is 36V

Hi, Thanks for your video, what sort of diode would you recommend between the 2 motor contacts?

I have a major upgrade, ditch the internal pump and run a ac vacuum pump externally.

I did the mod, and it brings the fan speed down to generate much less, and less annoying, noise. However, the 1 ohm dropper would have 18 - 12 = 6 volts over it, which means a 6A current would be drawn (although I didn't measure the actual voltage over the dropper, just assuming 6V). The replacement bucket converter is rated for 5A. Potentially a problem?

I'd love to know if anyone else in Australia has managed to procure a ZD-915 recently. I tried and failed, so I ended up settling for a Yihua 948. It does a better job than a manual solder sucker, but the build quality doesn't exactly inspire confidence. Seeing this video, and how a ZD-915 can be modded like this, makes me kinda wish that I tried a bit harder to track down a ZD-915.

Ive been using my zd915 for a couple years. Definitely got my moneys worth. I wanted to grab a heating element for if/when mine goes out but all that available is the parts for the proskit new version. I wanted to order the whole new priskit gun but its 7 pin and the zd915 is 6 pin. Any idea what the extra pin is for? Would you still suggest the buck converter mod? Thanks

Intersting. I thought that the higher-quality buck converter would be a notable improvement.🤔 However, I did know that attaching the hose would improve the suction strength.😜 On a serious note, it is difficult to find that SD-915 here in a 120VAC version. I'm curious does the tranformer indicate that it might be 120VAC configurable?

@TheRetroChannel How is this compared to the WEP Yinhua 948 ii

Just drop an lm7812 12v reg across the fan power.

Did you print the case for your Buck converter?

Your "303 UV protectant" ebay link is dead.

Hello All. I'd like to try this mod but being VERY amateur with electronics, could somebody out there give me "monkey see, monkey do" instructions, please? Wiring up the fan is straightforward, but not the rest. Many thanks.