Looking for help about a ZD-915 desoldering station - UK Vintage Radio Repair and Restoration Discussion Forum

madscientist · 18th Nov 2021, 11:15 pm

Hello everyone.

I am located in Buenos Aires, Argentina.

I have an old, likely 2012/2013 made ZD-915 desoldering machine.

Vacuum Pump has DC motor, it has a Buck circuit for the cooling fan and the vacuum unit, uses 6 pin gun. It's a 220v, 50hz model, i don''t know how to tell wether it's ESD safe or not.

Today i got my 3rd gun.

The original gun lasted until early 2020, i had use it heavily on motherboards and other repairs. The first spare gun i got lasted from early 2020 till August.

Given the time i had been using it, and the fact i lost a gun too early, i had service it replacing all the electrolytic caps in the power supply board and in the display board. I also did replace, one at the time, some wires going from the display board to the gun connector.

After such job, today i had plug the new gun, it works excellent but i have a strange behaviour: after some time on, at any temperature i chose, it sets itself into 200 celsius, then i have to touch any key to get back to the temp i use for desoldering components.

I had learn many machines use the same display board and likely the same power supply. It sounds like i had enable a feature in my machine by accident. ZD-985 model seems to have this feature by default, and the ZD-915 is not supposed to have it.

The first time i saw this, with the 2nd gun, i had open again the power supply board suspecting some sort of mistake and i found i forgot to solder one pin of a transistor. i did solder it back and everything stays the same. No smoke, no problems with temperature, nothing. It just keeps setting itself to 200c.

I would like to ask if does someone know if it does have some sort of jumper-like switch, solder-drop bridge i may have removed or a likely mistake i may have done or if i can try and change something else y may be missing.

Just let me thank you for your help.

Herald1360 · 21st Nov 2021, 11:44 pm

It sounds like a bit like a life extender function. The drop in temperature after a while reduces the rate of oxidisation and thermal stress on the desoldering bit, the touch any control to return to preset temperature is typical of such designs.

Why would you want to disable it?

paulsherwin · 22nd Nov 2021, 12:52 pm

Sorry, but this is modern technology so is off topic here and cannot be discussed.

If you can help the OP, then please contact him by private message.

18th Nov 2021, 11:15 pm	#1
madscientist New Member Join Date: Nov 2021 Location: Buenos Aires, Argentina. Posts: 1	Looking for help about a ZD-915 desoldering station Hello everyone. I am located in Buenos Aires, Argentina. I have an old, likely 2012/2013 made ZD-915 desoldering machine. Vacuum Pump has DC motor, it has a Buck circuit for the cooling fan and the vacuum unit, uses 6 pin gun. It's a 220v, 50hz model, i don''t know how to tell wether it's ESD safe or not. Today i got my 3rd gun. The original gun lasted until early 2020, i had use it heavily on motherboards and other repairs. The first spare gun i got lasted from early 2020 till August. Given the time i had been using it, and the fact i lost a gun too early, i had service it replacing all the electrolytic caps in the power supply board and in the display board. I also did replace, one at the time, some wires going from the display board to the gun connector. After such job, today i had plug the new gun, it works excellent but i have a strange behaviour: after some time on, at any temperature i chose, it sets itself into 200 celsius, then i have to touch any key to get back to the temp i use for desoldering components. I had learn many machines use the same display board and likely the same power supply. It sounds like i had enable a feature in my machine by accident. ZD-985 model seems to have this feature by default, and the ZD-915 is not supposed to have it. The first time i saw this, with the 2nd gun, i had open again the power supply board suspecting some sort of mistake and i found i forgot to solder one pin of a transistor. i did solder it back and everything stays the same. No smoke, no problems with temperature, nothing. It just keeps setting itself to 200c. I would like to ask if does someone know if it does have some sort of jumper-like switch, solder-drop bridge i may have removed or a likely mistake i may have done or if i can try and change something else y may be missing. Just let me thank you for your help.

21st Nov 2021, 11:44 pm	#2
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Looking for help about a ZD-915 desoldering station It sounds like a bit like a life extender function. The drop in temperature after a while reduces the rate of oxidisation and thermal stress on the desoldering bit, the touch any control to return to preset temperature is typical of such designs. Why would you want to disable it? __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

22nd Nov 2021, 12:52 pm	#3
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,944	Re: Looking for help about a ZD-915 desoldering station Sorry, but this is modern technology so is off topic here and cannot be discussed. If you can help the OP, then please contact him by private message.