Dick Smith T-2200 soldering station element failure - Page 1
Forum section: electronics / repair

author: Nzoomed
author_rank: Newbie
timestamp: January 30, 2024, 02:35:37 am
content: I know there are a few Aussie and Kiwi members in here who should be familiar with this unit.They are a rebranded xytronic station and parts are readily available.Anyway it has not had a huge amount of use over the time I've had it, I bought it new before Dick Smith shut up shop.In that time I had to replace the element and I suspect the issue was with the thermistor inside.What would happen was the needle on the temperature meter would oscillate for a bit before it heated up, progressively it would get worse and either not heat up, or not stop heating and the tip would glow red.I replaced the element and all was sweet. I have not used it much in that time over the last 3 years or so after replacing it and now I've noticed the same symptoms again!My question is this, is there something in the electronics of the soldering station itself the cause of failure, or is it just coincidental that I've had a bad run of faulty elements?These soldering stations were a good workhorse at my first place of work 20 years ago and we had zero issues with them.Now before anyone says something, I do have other irons, I have a TS-80 that also has had a failed tip that burned out, am waiting for my replacement to arrive and have been making do with the T-2200 for the time being only to discover that I'm having this start to fail.Either way, it's a good soldering station and I intend to keep it as a second unit, it's a bit of nostalgia more than anything.Would be interested to hear if anyone else has had similar issues.

author: Nzoomed
author_rank: Newbie
timestamp: January 31, 2024, 09:16:04 pm
content: Bump

author: Chris56000
author_rank: Frequent Contributor
timestamp: January 31, 2024, 09:55:02 pm
content: . . .Can you post some pics & the Xytronic equivalent model please?There might be a circuit online we can assist you with!Chris Williams

author: Nzoomed
author_rank: Newbie
timestamp: January 31, 2024, 11:33:12 pm
content: Apparently it's based on this model which is still made today.Only difference being its got a digital meter.Original model would be a 168-3Chttp://www.xytronic-usa.com/shop/item.aspx?itemid=236

author: seronday
author_rank: Regular Contributor
timestamp: February 01, 2024, 11:11:24 pm
content: I had the same problem with my T2200 solder station with the temperature meter jumping around when first turned on and progressively becoming worse over time.The temperature sensor that is imbedded in the barrel assembly seems to be a K type thermocouple.At one stage I attached an external K type thermocouple sensor to the solder iron tip and connected it to the temperature sensor input on the control board. The temperature meter and control circuit then worked correctly.After that I fitted a replacement barrel assembly and so far that issue has not re-appeared.Attached is a copy of my hand drawn circuit for the control board.Regards.

author: Nzoomed
author_rank: Newbie
timestamp: February 02, 2024, 09:15:53 am
content: Quote from: seronday on February 01, 2024, 11:11:24 pmThat's interesting, perhaps it's a common problem?Do you think there is a faulty batch of the things or something?It's a bit strange how I have had two of them fail on me.Would be interested to know if this is a common thing seen with xytronics soldering irons.I might be available to slip in a new thermocouple inside the barrel assembly and see how that goes.Was just wondering if any other fault in the electronics could lead to the thermocouple failing?

author: Andy Chee
author_rank: Super Contributor
timestamp: February 02, 2024, 10:52:28 am
content: My original element had an open circuit thermocouple, heater circuit would never turn on.But yes, years ago when I bought a replacement heater barrel from eBay, I've also encountered an intermittent oscillation in the temperature control. I noticed when I turned the temperature control down, the oscillation would cease, and then I could turn the control back up again.So I'm not sure whether it's possibly a temperature range calibration issue that I never performed with the new heating barrel.

author: Bigfoot
author_rank: Contributor
timestamp: February 23, 2024, 12:19:27 am
content: I bought one of these Solder Stations from a DSE store when they went bust some years ago for $1. The element had been unknowingly faulty in the box. Anyhow I fixed it recently by replacing the hand piece with a Chinese YAXUN 936 50W 24V unit which can be had on Aliexpress for around $7 . These have ESD protection but you can ignore the 5th conductor .There are four other conductors two for heating element and two for thermocouple. You just need to get the thermocouple polarity correct. I'm satisfied with the result , it heats up correctly with the meter needle matching the dial setting.I dismantled the original hand piece and desoldered the incoming conductors , did the same with the new Chinese one and fed the T-2200 cable up the 936 hand piece , resoldered the conductors and reassembled. The tips are cheap enough too at $4 per 10.

author: ozcar
author_rank: Frequent Contributor
timestamp: January 19, 2025, 04:57:15 am
content: Quote from: Bigfoot on February 23, 2024, 12:19:27 amThe element in my one finally gave up the ghost recently. The thermocouple went open-circuit.I'm going to move to something more modern (work still in progress), but I'd like to keep the old station as a backup/spare, so decided to do what Bigfoot did. In my case the replacement handle was described as being for "YIHUA/WEP 24V 50W Machine". Heater measures at about 12 ohm at room temp, compared to about 11 ohm for the original. Unfortunate that the tips are different, but no big deal getting a whole new set.The devil could be in the sensor, but at least it appears to be a thermocouple, not some sort of PTC.The replacement works, and the meter reading matches what the dial is set to, but I found the temperatures to be a lot lower than I was used to. All I currently have to check the temperature is a thermocouple which has Teflon covered wires, supposedly OK only up to around 255C. With that I found that with the dial set to 300, the temp was only around 245.I can't turn up any calibration info for this device. The service manual for the similar T-2000 gives some clues, but that one seems to have less adjustments (has fixed resistors either side of the temperature control VR2?). I bit the bullet and tried tweaking the opamp gain (VR1) to get temp around 250 with the dial set to 250, but it was then a bit out at lower temperature settings, eg 163 when dial set to the minimum 150. The offset adjustment was a bit out, but correcting that via VR3 (and re-adjusting VR1 for correct temp with dial at 250) resulted in a greater error at lower temps.It is probably usable as it is, but has anybody else tried messing with the settings?FWIW, I see an error in the helpful schematic posted by Seronday (reply #4 here).That shows a 1M resistor from negative supply rail to non-inverting input of opamp (pin 2). This is wrong - this resistor, designated R3A on the PCB, actually goes from negative supply rail to junction of VR3 and the 10K resistor. The PCB allows for alternative of R3 to positive supply rail, so you can have negative or positive adjustments, but have to move the resistor.