ZD-8915 (SS-331) conversion from 18V to 24V

[cybermaus]

Well, if it shows up as 12V during operations, a stable 12V, than that would in fact rule out the 12V module.
But then I am out of idea's.

[vdtoorn]

Thanks for your help, I've scoped the 12 V supply and the (now) 23.5V supply, they both look stable, nothing dramatic, no spikes or the like.

I'll have to have a good look again, it's difficult to analyze because the fault goes away in around a minute, and does not return until after quite some time. I guess I'll test by heating up some parts and see if operation resumes to be normal. I also saw some sloppy solder blobs (no doubt coming from me) on the shell of one of the 'twin' electrolytic caps, I'll try to desolder it and measure if all is still OK there. Would be nice to have a desoldering station for that job

[alxtr1bal]

Hello guys;

I did this cool modification on my old station i bought some years ago , the PSU is the same version as OP. So i now have a steady 12v (from 23.5 to 12v with the converter) that powers the board with the switches for fan, display and pump.

My problem is that the temperature of the heater never stops ! it goes over 500, then the display says "Error" , but the heater continues to heat (even becomes red !!) ...

What could this be related to ? psu (opto isolator ?) , or the control board part ?

[vdtoorn]

You could have al look at the green wires, these go from the control board to the optocoupler

[Beau Geste]

PLS HELP!
the vacuum pump of my SS31 no longer works! I tested the current on the pump and it is only 4 volts. What could have happened? Any advice and/or suggestions will be greatly appreciated. Thanks 

[Beau Geste]

Hello guys;

I did this cool modification on my old station i bought some years ago , the PSU is the same version as OP. So i now have a steady 12v (from 23.5 to 12v with the converter) that powers the board with the switches for fan, display and pump.

My problem is that the temperature of the heater never stops ! it goes over 500, then the display says "Error" , but the heater continues to heat (even becomes red !!) ...

What could this be related to ? psu (opto isolator ?) , or the control board part ?

Hi,
I had the same problem. I solved it by buying another control board. Probably the fault is in the TL7805 and TL431 voltage regulators. Check them with the multimeter if they are OK or not .However, the control board does not cost more than 30 euros.
Ciao

[vdtoorn]

Ok, my saga continues, but now I've been silly: I've tripped the breaker in the house because I mistakenly probed pin 4 to ground on the oscilloscope ground - mixed up the pin order apparently. Or the fscq1565rt was broken. If not, now it is certainly broken, and the NTC decapitated itself with a bang .

So, I'm now going to order the fscq1565rt, from AliXpress because that's the last place that sells these ancient chips.

 

I'll have to keep my eye on the expenses, so I don't spend too much before it's better to replace the unit 

[alxtr1bal]

Hello guys;

I did this cool modification on my old station i bought some years ago , the PSU is the same version as OP. So i now have a steady 12v (from 23.5 to 12v with the converter) that powers the board with the switches for fan, display and pump.

My problem is that the temperature of the heater never stops ! it goes over 500, then the display says "Error" , but the heater continues to heat (even becomes red !!) ...

What could this be related to ? psu (opto isolator ?) , or the control board part ?

Hi,
I had the same problem. I solved it by buying another control board. Probably the fault is in the TL7805 and TL431 voltage regulators. Check them with the multimeter if they are OK or not .However, the control board does not cost more than 30 euros.
Ciao

Ciao there

Thanks for the suggestion, i'll check that !

Do you remember where you bought the control board replacement?

Thanks again

[alxtr1bal]

Hello guys, just to let you know, i replaced on my PSU the double schottky diode mosfet (that was shorted) (by a FQP50N06) , and the optoisolator for the temperature (that was shot) (by a pc817). 



Working again.

[Spawn]

@cybermaus thanks for posting this information.

I ordered a ZD-8915 couple of weeks ago from Eleshop, but it was in backorder and I had to wait 2 weeks before it get delivered, meanwhile I came across this topic and I also planned to do the modification.

Yesterday I opened up the ZD-8915, and it has (again) a newer version power supply (ZD150-PQ32/15) and it is still a 18V power supply.
Took a picture of the resistors around the TL431A, but it was hard to get a nice picture, it is buried between higher components, so far I can see it is now R20 which needs a parallel resistor on it, the value is 2K4 and I think it needs a 6K8 resistor parallel on it for +/-24V

I am not that great with this kind a stuff, can somebody please check for me if I got it right with the R20 and the parallel resistor?
The other problem is getting in there with a soldering iron to solder another resistor, since there is no room at all for the iron.

I hope that my picture is clear enough.

[Beau Geste]

Hello guys;

I did this cool modification on my old station i bought some years ago , the PSU is the same version as OP. So i now have a steady 12v (from 23.5 to 12v with the converter) that powers the board with the switches for fan, display and pump.

My problem is that the temperature of the heater never stops ! it goes over 500, then the display says "Error" , but the heater continues to heat (even becomes red !!) ...

What could this be related to ? psu (opto isolator ?) , or the control board part ?

Hi,
I had the same problem. I solved it by buying another control board. Probably the fault is in the TL7805 and TL431 voltage regulators. Check them with the multimeter if they are OK or not .However, the control board does not cost more than 30 euros.
Ciao

Ciao there

Thanks for the suggestion, i'll check that !

Do you remember where you bought the control board replacement?

Thanks again

Sorry for the late reply. Yes, I bought the control board on Allegro.pl.
https://allegro.pl/oferta/plytka-sterujaca-wyswietlacz-lcd-niebieski-zd-8915-11026793876?reco_id=17400eef-221e-11ec-9f46-0c42a1097bde&sid=041047f9c36843e364ecb91b45c568a2755aa386fe7

[Beau Geste]

Hello guys, just to let you know, i replaced on my PSU the double schottky diode mosfet (that was shorted) (by a FQP50N06) , and the optoisolator for the temperature (that was shot) (by a pc817). 



Working again.

Great! You can't go wrong. When the temperature is out of control it's either the Mosfet on the PSU or the TL7805 and/or TL431 on control board 

[cybermaus]

@cybermaus thanks for posting this information.

I ordered a ZD-8915 couple of weeks ago from Eleshop, but it was in backorder and I had to wait 2 weeks before it get delivered, meanwhile I came across this topic and I also planned to do the modification.

Yesterday I opened up the ZD-8915, and it has (again) a newer version power supply (ZD150-PQ32/15) and it is still a 18V power supply.
Took a picture of the resistors around the TL431A, but it was hard to get a nice picture, it is buried between higher components, so far I can see it is now R20 which needs a parallel resistor on it, the value is 2K4 and I think it needs a 6K8 resistor parallel on it for +/-24V

I am not that great with this kind a stuff, can somebody please check for me if I got it right with the R20 and the parallel resistor?
The other problem is getting in there with a soldering iron to solder another resistor, since there is no room at all for the iron.

I hope that my picture is clear enough.

Hi SPawn. No one got back to you? Sorry, but I have been busy, not paying attention to eevblog.
Anyway, the picture is really too fuzzy. If you want some advise on which resistor, you'd really have to try and get a clearer picture, where we can see what is connected to what.

[vdtoorn]

Hi, just getting back to the subject of the intermittent startup, that appears to be fixed!. Briefly, the ZD-8915 was not starting immediately but instead switched on/off all the time with a time interval of about 1 second.

It turned out it was due to the VCC of the FSCQ1565RT (the 5-pin chip PWM chip attached to the heat sink), that starts up with power from a capacitor to begin with, but later gets its power from a winding of the main transformer. The transition to that second state failed because of a cold/damaged solder joint of capacitor E5, in my case.
Apparently the capacitor got warm during the startup attempts and made contact so operation would resume after 20 times or so. A power cycle of the device would switch on immediately but the fault returned when everything cooled down.

Sorry to say that didn't actually fix it, admittedly I tried without the gun attached. I think I'll just reverse the voltage mod, but at least the fan and front-end are now running off a stable supply. Guess the high voltage took some part of the power supply out of spec

Kudos to Andy Watson working out the schematic, for the 8915 there is one difference I found for my version (v4): the bridge rectifier is not 4x 1N4007 but 4x 1N5399, which are rated 1.5A instead of 1A.

[radiofan]

FYI, I recently solved the intermittent startup problem on my ZD-915. I replaced E6 and D9 with a fast recovery diode (1N4937) and it is working again. I increased my heater voltage a tad, to 20V.

Much thanks to @Texmisure for the circuit diagram.

[vdtoorn]

Thanks for the information!

Could you explain what you did exactly? Did you change E6 with a better component, higher voltage or a different capacity?
And, you chose to not go to 24 volts, but only 20, do I understand that correctly? Did you think it was too much on the PS?

I did notice that running the electronics, fan and pump with a lab power supply, would go up to 2A @ 18 V, I thought that was a lot, maybe something went wrong there as well.

[radiofan]

Yes I replaced E6 with same value but slightly better spec (10uF 50V 105C). I think the original was failing at a certain voltage. The fast recovery diode helps it charge.

I didn't want to raise the voltage too much in case it triggers an over-current or over-voltage error condition, which also results in continuous resetting.

[vdtoorn]

Ok, I've been looking at my stocks and don't have any 10uF caps, but I do have 22uF. Do you think there is a reason not to use that?
(Sorry for being so intermittent, I don't have too much time to spend on this "lengthy project")

[radiofan]

You should use the original value of 10uF. They don't cost much and they are useful to have as spares.

[vdtoorn]

I did try the 22 uF, it did work but the 'tempo' of the switching was a bit slower to my mind. I will change it back and get me some fresh 10 uF as well.

I did find that 'simulating' a startup delay on the buck/boost converter after powering up everything worked fine as well, so I started considering a MOSFET startup delay, but I'm done with this project and want to start using the tool! Measuring the temperature of the PWM module showed around 100 C or something (not on the heat sink) a bit high for my taste. I get the feeling this modification is not right for my version of the power supply. Undoing the parallel resistor made the problems go away, so I'll just have to live with a slightly longer heat up time. The fan is nice and quiet though, so I think the DC voltage conversion is a great addition.

Thanks a lot for thinking along, and I hope my remarks may help others if they experience the same things. I'm quite the noob, so this has been a learning experience as well.

[Mouse69]

I've done completed several mods to my Duratool ZD915, which has been in bits due to building work on the house for far too long..

• Reverse the PSU (remove it's cover), mains wires routed down the centre, between pump and PSU (otherwise they would get crushed by the cover)
• Reverse the pump and shorten the internal tube to the filter
• Increase the PSU voltage to 23.5V, I used a small multiturn pot attached via cables (no room to solder to the board easily)
• Changed the 2200uF 24V caps to 35V caps (just in case)
• Remove the dropper resistor board and use a buck converter, protected by a diode from motor back EMF (which has a snubber on it now)
• Using a Hakko nozzle

I have measured as best I can the pumps suction force:

[radiofan]

I opted to keep the resistor board for the pump and add a low-power 12V regulator for the fan only. So the pump works as before and it is much quieter now.

TBH, I don't see much advantage raising the voltage. I don't have a problem with heating up time.

[HumbleDeer]

@cybermaus It's time to revive this thread again 

In your original post you noted you'd like to link the sleep switch to the actual trigger switch.

Do you by any chance know which wire was connected to any/the sleep detection wire? What was the colour of this wire? Is the sleep wire active-high or active-low? I'm positively tired of the station going into sleep mode and not waking up until I raise/lower the temperature.

TBH, I don't see much advantage raising the voltage. I don't have a problem with heating up time.

The higher voltage on the heater element also gives it more power in response to temperature drops. It keeps up better with changes and drainage from a joint being heated.

[burro]

My two cents on this soldering station (probably not what you want to hear)

So I live in the US and purchased the SS-331H they sell on Aliexpress, Banggood, etc. and I have been testing it and it performs extremely poorly. The 350c you see on the screen is a fake temperature, in reality the gun only gets to about 240c (measured by a thermocouple). Basically unusable.

I thought that there was something wrong with the gun so I sent an email to Pro'skit support. They basically told me that I am SOL and that the reason why the gun was not heating up properly is because the SS-331H is designed for the chineese market (230v) and that it will never heat up properly. They said that the one I had to buy was the SS-331E (the white unicorn nobody can find), well it turns out you can find it now. They only have one authorized distributor int eh US which is Eclipse and Eclipse sells it to other US retailers. The station basically costs $211 however I has able to fin it for $179 with free shipping. (google it if you are interested, but finish reading this first)

On the other hand you have the Japanese brand HAKKO FR301 which according to every video I have seen online performs better than any Chinese made station (including this one used in Europe with 220V) and costs $166, on top of that it is built with quality materials and parts that will have to be replaced less often, so what I am getting at is why in the world would anybody buy this station?

It is not worth doing all of these modifications and creating a frankenstein that in the end is going to cost you even more and not designed to work with 110V and might even shorten the life of your heating element.

Just buy the Hakko and call it a day. I wish I would have done that since the beginning now I am stuck with a $150 paper weight.   

[cybermaus]

Do you by any chance know which wire was connected to any/the sleep detection wire? What was the colour of this wire? Is the sleep wire active-high or active-low? I'm positively tired of the station going into sleep mode and not waking up until I raise/lower the temperature.

When I need it, it is usually just because I am desoldering just one connector, one wire, one THT component. SO I turn it on, desolder, and turn it off again to avoid wearing the tip.
So the sleep practically was not the problem I expected it to be. So sorry, I never did anything other than as shown in first post.

My two cents on this soldering station (probably not what you want to hear)

Well, info that the device is basically not useable in 110V countries, if true, would absolutely be what people should hear.
Please reconfirm if that is what you meant.

And also, it depends on how often you use it. For me, in a 230V country, a hobby user, but also THT is getting less common anyway, I am quite happy with it.
Would I, or others, be happier with a proper brand? Like would I be happier with a Volkswagen instead of a Yugo? Sure, if I can (or want to) spare the budget. But maybe a Yugo can do  the job well enough.