ZD985 flashes on randomly - Page 1
Forum section: electronics / testgear

author: rilliam
author_rank: Newbie
timestamp: December 14, 2017, 12:04:05 pm
content: I have a ZD985 Desoldering Station that randomly turns itself on momentarily.Power cable plugged into AC.Front rocker switch set to OFF position.How can I fix this? Is my house going to explode?

author: GreyWoolfe
author_rank: Unknown
timestamp: December 14, 2017, 05:58:36 pm
content: I am curious to see what anyone thinks. I also have one but it has never behaved like that.

author: stj
author_rank: Super Contributor
timestamp: December 15, 2017, 12:42:26 am
content: saw that, check the power cable NOW!!!some have L & N reversed!!!!!

author: SparkyFX
author_rank: Frequent Contributor
timestamp: December 15, 2017, 02:13:19 am
content: Quote from: rilliam on December 14, 2017, 12:04:05 pmMy recently bought new unit does exactly the same thing. It seems to be the LCD Backlight and nothing else. It even does this when the power is switched off on both lines at the socket.I think it stopped for a while when i pulled the cable out of the unit, but have not further investigated the issue - i only see a short (~ 100ms) flash of green light like every 5 minutes or so - which is kind of disturbing when you are not sure what was going on left or right of you.The plan is to open the thing and check if it is a capacitor discharging or wakeup of the unit and increase bleed or whatever it is by adding a resistor parallel to the backlight.And i live in a country where there is no rule if Phase or Neutral needs to be left or right side... because an open Neutral line in the installation makes all Phase or Neutral lines suddenly hot.

author: stj
author_rank: Super Contributor
timestamp: December 15, 2017, 11:47:22 am
content: just meter the power cable between the 2 ends.

author: Ranayna
author_rank: Super Contributor
timestamp: December 19, 2017, 03:50:52 pm
content: I can confirm that switching Hot and Neutral seems to cause this.I have a ZD-915 which has the same issue. Since there are no polarised plugs in germany, the fix was easy: Just turning the plug around. The flashing has stopped completely.But hoestly, i do not understand why this effect happens with switched polarity. Am i going in the right direction, saying that there seems to be some kind of leakage happening, since the neutral is switched and not the hot?

author: Questjon
author_rank: Newbie
timestamp: December 30, 2017, 02:31:51 pm
content: Thought at first that the flashes were my imagination. Switching the plug around is not an option since I have 2 phases (230VAC between phases in my house ). Guess I have to open the box and put some bleeder resistance to ground from the display or something like that.

author: ciccio
author_rank: Frequent Contributor
timestamp: December 30, 2017, 04:24:53 pm
content: I've bouhgt one recently (really satisfied fir that price) and I've nevere noticed it switching on randomly, BUT I've opened it for my usual safety check on Chinese mains wiring, and I've seen that there is a 2 pole mains switch but it switches only Live. Neutral is always connected. A third wire carries Neutral to the switch for powering the neon lamp inside.If you have Live and Neutral reversed maybe some filter cap in the switching PSU may bleed and switch it on randomly....I think it should be very simple simple to open the station and wire also the Neutral to the switch (to switch both Live and Neutral). Pay due attention to the wire colors: in mine Live is red and Neutral is black, but I will not be sure that Ningbo Zhongdi has a standard....As soon I have some time I'll rewire the whole thing correctly.Best regards