Miniware TS100 Soldering Iron Display Replacement

Introduzione

At 2017 MiniWare released TS100 soldering iron. With portable design, temperature control, tips with inductive heating (they warm up very fast and was a novelty 7 years ago), wide power voltage range (12-24V) via standard 5.5x2.1mm Jack connector and open source design (firmware and schematics are openly available) and very affordable price (aprox. 80 USD/EUR on release) it became immensely popular in EE and RC hobbyist community. I still use it as my field iron for repairs outside home.

TS100 has small, but bright and crisp monochrome 0.69" OLED display with 96x16 pixel resolution. Display module contain the Adafruit SSD1306 compatible OLED display and I2C interface. Unfortunately first OLED screen generations was short-lived and this display was not an exception. After 7 years due to burn-in my iron screen became too dark to see something. Now it is time to replace it.

In this guide I will tell about TS100 display replacing steps. And some caveats and issues worth to know and how to avoid them.

Cosa ti serve

Passo 1 Disassembly

Miniware TS100 Soldering Iron Display Replacement, Disassembly: passo 1, immagine 1 di 3

Miniware TS100 Soldering Iron Display Replacement, Disassembly: passo 1, immagine 2 di 3

Miniware TS100 Soldering Iron Display Replacement, Disassembly: passo 1, immagine 3 di 3

With hex screwdriver or bundled hex key remove two tip retention screws. Pull the tip out.
Remove grounding screw.
With prying tool carefully open the soldering iron handle casing, starting from tip socket side. Try to avoid breaking the holding pins near display edges at both casing sides.
Carefully pull out the small controller chip board near power and MicroUSB sockets.
At this step is recommended to put clear sticky tape over black button heads at casing face side. It will help to keep them in place during main board board removing and installing.
With Philips #00 screwdriver remove two contact clamps at tip socket side.
With a help of prying tool carefully pull out the main circuit board, starting from tip socket side.
During main board removing do not lose the grounding ring and two small black plastic button heads at casing face side.

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Passo 2 Display detaching

Miniware TS100 Soldering Iron Display Replacement, Display detaching: passo 2, immagine 1 di 1

Put tweezer tips between display module and two-sided adhesive sponge cushion between display and circuit board at free display end. Keep sponge in place and very carefully wiggle the display module upwards. It should come off the sponge with sponge remaining intact. Do the same with second sponge at flat cable side.
Warming up the sponge for 10 seconds with hot air from heat gun or hair dryer will help to free display from sponge much easier.
If you don't have spare EVA sponge, you can carefully remove the sponge cushion at display cable side and stick it nearby for later use. Sponge removal from circuit board is the same as removing from the display module.

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Passo 3 Desoldering the old display

Put the flux over flat display cable contact soldering line. I marked it with green arrow at second photo. Turn the soldering iron to 300C (570F) degrees. Heat the soldering line from one side and with tweezers carefully pull the loosened cable away from circuit board.
Be extremely careful on cable removing at top side in photo. There are two dead end tracks with pads that can easy lift up or get torn off and go away with display cable. Try to avoid that.
Work will be easier when circuit board is held in some soldering helping hand tool with soft coating around grips or in little vice. Be careful though and don't destroy any components on circuit board.
Flat cable desoldering is easier with shovel type T12-1402 tip or other similar flat wide tip. This will melt the solder in all cable width at once. Thus make removal process shorter and stress the circuit board less.
If you have difficulties with melting the solder: 1) use more flux. 2) turn soldering iron temperature 10-20 degrees warmer - many soldering irons show larger temperature number than tip actually have. 3) Use even more flux - do not skimp on it.
After cable removing clear solder remains from pads with desoldering braid. Clear the board around pads with cotton bud, soaked in PCB cleaner or isopropyl alcohol.

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Passo 4 Damaged pad preparing (optional)

If during cable removal one or both dead-end pads lifted or got torn off, it is not complete failure yet. You have two options:
If pad is lifted, carefully arrange it in old position - different color area (yellowish, not green) under the pad. Put a dab of solder paste over it. Then carefully put desoldering braid above it, warm the spot for few seconds and let it cool off. Soldering paste will glue the pad back in the place. Clean the area afterwards.
If pad is completely torn off, inspect the area directly behind it where track from pad went further to small black resistor side. With scalpel carefully scrape off the green lacquer in 1mm length to reveal track copper. Put flux over it and tin the cleared track area. Clean the area afterwards.

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Passo 5 Soldering the display module

Miniware TS100 Soldering Iron Display Replacement, Soldering the display module: passo 5, immagine 1 di 3

Miniware TS100 Soldering Iron Display Replacement, Soldering the display module: passo 5, immagine 2 di 3

Miniware TS100 Soldering Iron Display Replacement, Soldering the display module: passo 5, immagine 3 di 3

Put a line of flux paste over pads and flat cable end.
Take the display module with face side down. Put the flat cable on cleaned pads on circuit board. Arrange the cable over pads to left free pad area a little less than 1mm from the left side (in second photo).
Set soldering iron temperature to 270C (520F). Tin the soldering iron and solder the cable to the board.
Be careful. During soldering keep the cable pins directly above related board pads. Try to avoid board overheat though very long heating.
Solder the first and last cable pin before soldering the rest, That will keep the cable in place during soldering the remaining pins.
Cable soldering is easier with thin oval T12-BC2 tip or other similar tip. Otherwise you will need to use a lot of flux paste to avoid solder clumping in large area with pad shorting in result due to thick tip that help solder spread where it is not desired.

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Passo 6 Post-solder inspection

Inspect the cable soldering. If some pads and cable pins are shorted with solder bridges, put flux paste around the spot and remove excess solder with clean soldering iron tip. If necessary - with a help of desoldering braid.
Clear the board around pads with cotton bud, soaked in PCB cleaner or isopropyl alcohol.

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Passo 7 Restoring connectivity for torn pads (optional)

Miniware TS100 Soldering Iron Display Replacement, Restoring connectivity for torn pads (optional): passo 7, immagine 1 di 1

With a piece of jump wire or thin regular wire (AWG32 and thinner) connect the display cable pin above torn pad and related tinned track area (from step 4).
Put a drop of flux paste above this. Carefully solder both wire ends to cable and track while keeping the wire in place with tweezers.
Inspect the area for accidental soldering bridges. Remove them if any.
Cut the free wire left behind track soldering with a scalpel.
Clean the area.

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Passo 8 Testing

Inspect the area against accidental solder bridges and debris. Remove them if any.
Connect the controller chip board to the main circuit board.
Plug the power supply or an USB cable with MicroUSB connector into appropriate connector on main circuit board.
If repair was successful, either Miniware logo with subsequent "Press ..." or "CONFIG" (when USB cable is plugged into MicroUSB port) will appear in the display screen.
If nothing happens, check if connected devices are powered on. If they are powered on, chances are that you either forgot to connect the controller board to circuit board, not all display cable pins and torn pad wires are soldered carefully enough or there are remaining shorted display cable pads. Inspect the pads and cable again and fix that.

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Passo 9 Display attaching and arranging

Prepare two adhesive EVA sponge cushions in approx. 10mm x 5mm size. Put them under the display module at both ends.
... or use the kept sponge cushions instead if you don't have the spare EVA sponge roll and were careful enough.
Stick the display module above sponge pads. Free module end must be at the spot with a perpendicular line on the board before a row of little back resistors. Display module screen must lie strictly in parallel with circuit board.
Insert the circuit board in casing, starting from power connector side. Plug in the power and check if display screen is arranged strictly in parallel with the glass window at the casing face side circuit board. If not, take the board out and correct the display module placement. If needed, repeat till screen is arranged correctly.
Take the board out. Blow away and clean the occasional dust and debris from display and inner casing glass window side.

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Passo 10 Assembling

Insert the circuit board in casing, starting from power connector side. Before inserting the opposite board end put the tip grounding ring to the end of board with two prongs to board side below the board.
Keep attention to the small black plastic button heads at the face side of casing. They are prone to jumping around and get lost if not fixed with a sticky tape from outside.
Insert back two tip contact clamps. The clamp with wider bottom is located more inside the board. Both clamps have fixing pins at the opposite end of screw hole that must go in appropriate holes in the board. Screw the pads to the board.
Inspect are the small controller board firmly sit in the place. If board is loose, carefully push it in till it stop.
Put something thin and strong between tip grounding ring and first contact clamp before installing the casing back cover. Like bundled hex bit, thin screwdriver or small nail.
Install the casing cover starting from the power socket side. Before closing it pull inserted bit outwards to make tip grounding ring stand exactly along the socket wall without free space between. Push the cover - it must freely move inwards over the ring. When it happen, pull the helper bit out and push the cover till end to close it.
Put back casing screws. The long screw into a hole with grounding symbol. Both short tip retention screws - to holes around the tip socket.
Insert back the soldering iron tip. Fasten it with retention screws.

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Passo 11 Final testing

Miniware TS100 Soldering Iron Display Replacement, Final testing: passo 11, immagine 1 di 1

Plug the power in the soldering iron. See the bright text on replaced display screen and feel happy.

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Conclusione

TS100 soldering iron display module replacing is not very hard repair. Even easier if you have previous soldering experience and tools for work with microelectronics. Do not hesitate to do it if your iron display fail due to old age. Be careful and do not skimp on flux paste - it is expendable anyway ;)