18VDC PSU has dropped to 10v - ZD-915 desoldering station

[sam_sam_sam]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

now another tip.
dont spend money on filter discs

but an A4 size sheet 0f 3mm ceramic wool gasket.
like this: https://www.ebay.co.uk/itm/223837165275

and a leather punch.
like this: https://www.aliexpress.com/item/32826370605.html

Thanks for sharing this information

[hdtvman]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

it isnt 18v to the fan, because it goes through a couple of wirewound resistors.
the fan is shit though. i replaced mine with a sunon maglev fan and a 9v buck convertor

Right you are! Actually, I measured at the fan connector after the resistors and it does still read 18v going to the fan. So I decided to replace the 12v fan with a Suncom 24v ME50152V1 which draws 2.8w. The unit is much quieter and holds temperature better (less peaks and overuns in temperature listed on the lcd screen). My guess is that the loud whining 12v fan was inconsistent in voltage/amperage draw due to running above spec and was causing instability issues in temperature This is the fan I got: (sh*t fan on left, good one on right) probably some bean counter decided to reduce costs on the fan.

[sam_sam_sam]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

more pictures as requested :-)
main board has 110vac coming in and 164v dc at transformer primary and also at T1 transistor. Nothing at all coming out of the secondary. did not see an obvious F1 thermal fuse - maybe its internal to the transformer... (edit: just read above post - these don't have any - thanks!) also no voltage going out to secondary boards (LCD and controls) no 5v or 18v at the connectors. Reflowed all the dubious solder joints, no joy.

I guess it took a shit again

Well I have some answers to the question about why this Desoldering station did not work correctly
Yea I know that this is a old post but he reached out to me about trying to repair it and this is what I found out

Two of the winding are shorted so it has seen better days

[stj]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

re-wind it

[sam_sam_sam]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

re-wind it

I have three issues with doing this

One where do you get the correct diameter winding wires from which is the biggest problem

Second where do you get the wrapping tape from

Third I have never done this before

However I have watch YouTube video on how it is done

Can you please offer some advice the first two issues and I will figure out the last one

[stj]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

you can watch diode gone wild for unwinding them,
wire diameter can me determined - tape can be capton
https://www.youtube.com/channel/UCQa...B_Kd54g/videos

if your lucky, they may be touching at the base where they go to the pins and you could seperate them and insulate with some laquer

[sam_sam_sam]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

you can watch diode gone wild for unwinding them,
wire diameter can me determined - tape can be capton
https://www.youtube.com/channel/UCQa...B_Kd54g/videos

if your lucky, they may be touching at the base where they go to the pins and you could seperate them and insulate with some laquer

I have watch his videos before on this

But my question is where do I buy the right winding wire to do this with

I would not trust this wiring because it already has this issue I want to use good quality wire

[stj]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

use a digital caliper to check the original wire,
you can buy rolls of enamelled copper wire from the usual places - or just unwind some junk transformer.

[sam_sam_sam]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

use a digital caliper to check the original wire,
you can buy rolls of enamelled copper wire from the usual places - or just unwind some junk transformer.

What just old fashioned transformer would work I will have to try this

[stj]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

it's just coated copper wire

[sam_sam_sam]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

I have modify one of my Desoldering stations with a 24 volt fan instead of the 12 volt fan that is in it I will see how well this works very soon I also have another one that the fan has also gotten noise so I need to replace it before it starts squeaks real loudly

[sam_sam_sam]

Re: 18VDC PSU has dropped to 10v - ZD-915 desoldering station

I guess it took a shit again

Well I have some answers to the question about why this Desoldering station did not work correctly

More damage found two of the 4 diodes shorted on the main power supply rail to the regulator ic chip now waiting for diodes from EBay to show up to see if the spare switching power supply transformer is going to work correctly on this board or are there more issues and damage to this board

I also I have a feeling that the switching power supply regulator that was replaced might be a fake because the company logo does not look right for some reason because the detail is not in the logo like it should be I have also replaced my before and I bought them from Digikey and I know that those are real

Also there is a trace on the board where one of the pins to the switching power regulator is like burned off it is repairable but not easily because of the pins are so close to each other

[m.saravisa]

sam_sam_sam Do you manage to fix the ZD-915 desoldering station?

[sam_sam_sam]

sam_sam_sam Do you manage to fix the ZD-915 desoldering station?

Welcome to the forum

What is is your exact issue with your desoldering gun station example switching power supply controller issue
if you are having switching power supply issues please read this post

https://www.badcaps.net/forum/troubl...g-power-supply

Here is another post about this topic

https://www.badcaps.net/forum/troubl...g-power-supply

I personally would not waste my time trying to figure out what is the issue with the original switching power supply because it has been my experience that the repair does not last especially if you have used it for many hours of use because this is what drove me to find a better solution for a switching power supply that can be repaired or just replaced with another new one

Because the original switching power supply is not a very good design or quality so you are at it mercy to weather or not it will continue to work properly or not

You do not say where you are from because I do have several original switching power supply that I am not going to reuse for anything if you are interested in one please PM me and we might be able to work something out together depending upon where you live

[stj]

i have not seen any fail.
i wonder if it's the fact that your only using 120v makes the pwm run at a different duty cycle with double the on-time?

[Agent24]

I know this is an old thread but how do you determine the windings are shorted when at least one shows good on the ring test?
If any winding is shorted, it should affect all windings and none should have high rings, as far as I know.
Or is there a special case where this can happen? Would be interesting to know!

[m.saravisa]

Welcome to the forum

What is is your exact issue with your desoldering gun station example switching power supply controller issue
if you are having switching power supply issues please read this post

https://www.badcaps.net/forum/troubl...g-power-supply

Here is another post about this topic

https://www.badcaps.net/forum/troubl...g-power-supply

I personally would not waste my time trying to figure out what is the issue with the original switching power supply because it has been my experience that the repair does not last especially if you have used it for many hours of use because this is what drove me to find a better solution for a switching power supply that can be repaired or just replaced with another new one

Because the original switching power supply is not a very good design or quality so you are at it mercy to weather or not it will continue to work properly or not

You do not say where you are from because I do have several original switching power supply that I am not going to reuse for anything if you are interested in one please PM me and we might be able to work something out together depending upon where you live

Thanks Sam for the respond and link attach appreciate a lot and sorry my English not that very good. And yes i manage to fix my power supply unit after few try. The first time i encounter was the explode sound from main unit. After dismantle found damage FSCQ1565RT and zener diode 1N4746 after replace power on the unit intermittent like no enough power and after while no power at all. I'm not electronic expert like you guys but have interested in electronic basic repair. I'm just self taught hobbies learn from google and experts like you guys here . Back to topic i did try again go through very single component all look good and suspect only the transformer and i have the same anatek ring tester like yours too and measure the same way as you do and the result is same as your attach picture. I google around how to use ring tester to measure transformer and found out its different method like this https://www.youtube.com/watch?v=cxBBchUW4xo .So t
he transformer is good working condition if follow the youtube method. I try one last attempt before discard the supply unit into dustbin and finally manage to find the culprit for my case its a Zener diode. When i measure use diode mode with my multimeter its shows good reading when try with peak zener diode tester the reading shows only 8v something suppose 18v. After replace the Zener diode yes its work again as normal for my case almost 40min plus usage. Future i don't know when it will give away again.

[Agent24]

Maybe the zener is underrated, try replacing it with a higher wattage one, I guess?

[sam_sam_sam]

Future i don't know when it will give away again.

This is the problem with the switching power supply in these desoldering stations you might get it to work again but for how long before it is not repairable because of not being able to get the switching transformer which also seems to fail in a strange way because I have had this happen before and got very discussed with trying to keep repairing them and when I found a switching power supply that could power both the desoldering/soldering station I bought one and modify the original switching power supply for its different power supply rails that are required to operate the controller board and the heater element and the vacuum pump and the back light panel

When I used my desoldering/soldering station I have it on for hours at a time this is the reason I went to a series that has the sleep feature on it because I not always sitting in front of it soldering or desoldering something but it is a hassle to turn it on and off repeatedly just to get something done

[petehall347]

think mine is this one .fast warm up time nice people to deal with . had my stand alone iron fail at around 20 years old and had it replaced for free and other bonuses because of a very rare manufacturing fault far from the cheapest but it works . https://www.chronos.ltd.uk/product/a...ering-station/