ProsKit SS-331 Soldering gun replacement heater - Page 1
Forum section: electronics / repair

author: Acecool
author_rank: Regular Contributor
timestamp: November 24, 2021, 03:23:38 pm
content: Hey, I purchased the SS-331 desoldering station and it has been working well, but I wanted to use a different heater ( larger to hold more heat and with more accessible tips ) so I purchased a replacement heater... The other desoldering guns have these larger heating elements and larger tips but the proskit has a thinner one.There is no wiring diagram - I know there is a thermocouple to read the temperature and I just want to make sure I don't wire it incorrectly. There are 4 white wires and 1 blue. The blue is spot-welded to the external metal ie: ground. There are 2 wires close together and 2 far away which look like they may go together. Or it is separated by side.I'm just curious if anyone has a wiring diagram for these soldering guns and the larger elements from the older version. I will be checking with my multimeter and I'll probably identify the wires that way but it doesn't hurt to ask...There are no identifying marks on the heating elements - but the tips are slightly concave on the bottom, the tube from the heating element sticks out of the front a little and into the tip.This is like what I bought:https://www.banggood.com/ProsKit-SS-331H-Electric-Solder-Sucker-Desoldering-Device-Anti-static-High-Power-Strong-Suction-Desoldering-Pump-for-PCB-Circuit-Board-Repair-p-1375060.html?cur_warehouse=CN&rmmds=searchorhttps://www.banggood.com/ProsKit-SS-331H-Electric-Solder-Sucker-Desoldering-Device-Anti-static-High-Power-Strong-Suction-Desoldering-Pump-for-PCB-Circuit-Board-Repair-p-1375060.html?rmmds=myorderReplacement gun so I could use both:https://www.aliexpress.com/item/Pro-sKit-SS-331H-Accessories-Electric-Desoldering-Station-Tin-Gun-Suction-Tin-Pump-Filter-Pipe-Nozzle/1005002636502460.html?spm=a2g0s.9042311.0.0.14494c4dxlmt0kand the heater is:https://www.ebay.com/p/1228540148?iid=401736356140

author: TheBay
author_rank: Unknown
timestamp: November 24, 2021, 06:46:11 pm
content: Quote from: Acecool on November 24, 2021, 03:23:38 pmI've got a ZD-8915 (Same as the SS-331) here and a few spare guns (The elements don't last long) and also have been thinking about fitting the larger heater too.I can't tell you off the top of my head what wire goes where, but I can have a look if you can't figure it out.Make sure you get the polarity correct on the thermocouple when you wire it up.Have you got the new heater yet as I wanted to make sure it is physically compatible with the gun?I was going to order a gun or heater for the ZD-8925 and modify it as the mine has a 7pin DIN (Sleep) and the ZD-8925 is 6pin.I ended up buying a Quick 201B desoldering station in the end, but if a bigger element can fit the ZD-8915 I'll fit one and use that for stripping boards.

author: Acecool
author_rank: Regular Contributor
timestamp: November 27, 2021, 01:51:41 pm
content: I did get the thermocouple correct but still got an error so I think the heating element is either backwards or the solder didn't properly bind as it wasn't sticking properly to the one wire so I may need to use physical connections instead of the solder-ring-heat-shrink things...My multimeter didn't detect the thermocouple properly but my thermometer thing did..'edit: Since I have to take it apart again anyway, and I'll probably test before putting it together - I'll take some photos of everything... I also have the colors of the wires defined...Inside HandleRed = Thermocouple - Note: When you snip the wires, I recommend cutting one through the center of the physical binding and the other through the wire or differently enough that you can tell which is which. Then, check the thermocouple polarity and mark the wire - I used a black sharpie for the negative. I'll see about getting the actual pin-out so there is less work... I am using the 5 pin KSGER unit.Red = ThermocoupleGreen = GroundBlack-Switch / Black = heater - probably negativeBlue = PowerHeater Element ColorsWhite = ThermocoupleWhite = ThermocoupleBlack = GroundBlue = HeaterBlue = HeaterNot sure which side is ground but I could probably just apply a voltage on the old heater with the unit with the old one apart so I know which side is which... although the new heater has a ceramic goop or something covering up the connectors on the outside unlike the smaller old heater which has them exposed with a sheathing over it.Edit: One other side-note... The larger heater comes with a longer tube which doesn't fit into the glass tube... I have 2 options for this... Either I cut the tube ( and to do this I'd probably take a metal wire slightly smaller than the tube itself and put it inside then use my flush snips and go around the tube until it separates - so it doesn't get crushed... I could file it shorter... Or I could cut a small channel in the silicone at the end of the glass for it to fit in, since it is longer it will fit inside and may have a good seal that way... also if I make the channel a simple slit, it could also seal itself that way... I'll probably file or cut or see if I can get a miniature pipe cutter for it.

author: TheBay
author_rank: Unknown
timestamp: November 27, 2021, 01:59:40 pm
content: Quote from: Acecool on November 27, 2021, 01:51:41 pmYes you will definitely need to crimp them, did you verify the resistance of the heater? it doesn't matter which way you wire the polarity for that.And will it physically fit the gun including the spacer?

author: Acecool
author_rank: Regular Contributor
timestamp: November 27, 2021, 02:04:06 pm
content: The resistance on the small one was like 50 or so - I'll have to remeasure and the resistance of the new one is 0.2 or something like that.It bolts on perfectly, aside from the tube being slightly longer which fits into the glass piece but that needs to be trimmed...I do have some dupont wire connectors - that's all I have so I could cut off half of it and use the part the wire fits in to crimp them together... I do have some resistors if I need to add one - but I still need to double check if the thing is even making contact.edit: attached are them assembled so you can see they fit and how much longer the tube is - I'll measure it in a bit.The heater by itself has the ground on the bottom, the positive white thermocouple on the left and the negative on the right.

author: TheBay
author_rank: Unknown
timestamp: November 27, 2021, 02:07:08 pm
content: Quote from: Acecool on November 27, 2021, 02:04:06 pmDid you bolt it on with the plastic spacer for the old heater?I wonder if the station throws an error if it does not see the resistance it expects and that the element resistance differs between models?Resistors won't work, you may have to modify the base station if that is the case or there might be an adjustment. I see 2 pots inside mine but I don't know what they do, I can only assume temperature calibration.The heater kit you ordered looks like it came with some brass crimps, were they missing?

author: Acecool
author_rank: Regular Contributor
timestamp: November 27, 2021, 02:15:36 pm
content: I updated the previous post with photos..I used the original plastic spacer and the original screws for it. They line up perfectly.I didn't see any in the packaging but I'll double check.I was really hoping to be able to use both depending on what I wanted to do...EDIT:Ok, so I'm glad I tested it with the cover off.... One of the wires glowed red hot as soon as I plugged it in... So one of the wires wasn't properly making a contact, I fixed that then tested it... The wire glowing I think was from the heater but the 2 thermocouple wires look black on the outside .. they were close to it... so some modification is necessary..OR, the heater is defective from the start... should heaters be close to 0 resistance? You'd think the resistance would be higher in the heater so the heat would be dumped there...OR - maybe because of the other connections made there was too much resistance with the solder, etc... and I need the brass connectors and I should cut the wires back a bit... The heating element did get warm in the 2 seconds it was plugged in so it could work, but maybe the issue is on my end from the solder connections....

author: TheBay
author_rank: Unknown
timestamp: November 27, 2021, 04:22:48 pm
content: Something is not right there. You mentioned 0.2ohm for the heater is that including the resistance of your multimeter leads too?Even anywhere near 1ohm the wires going to the unit will have more resistance and will heat up before the heater does.Either there is an error with your measurements/wiring or the heater is shorted somewhere.

author: Acecool
author_rank: Regular Contributor
timestamp: November 28, 2021, 11:32:50 am
content: I probably should've checked it when I ordered it - I am contacting the seller to see what can be done.