[SOLVED] Weller WD1(M) Display Repair (Replacement)

[stenzer]

Hi,

I got my hands on a dumped Weller WD1 for 20 € and I thought I will give it a try, as there was no specific fault stated. After powering up it was obvious that the display is faulty. For comparison here is a picture of the display of my WD1 during power-up.

And here the picture of an fully functional WD1 during power-up.

At this point I have to mention that I also "hijacked" a WD1 repair thread at [1]. It seemed to be the right place to address this issue, but no one responded .

(i) First I had checked the 5 V supply voltage used for the MCU (PIC18F6622) and the LCD driver (PCF8576), which is good.
(ii) As there was a HEX file provided at [1], I re-flashed the firmware. No changes at the display.
(iii) I measured (with a DMM) each individual pin of the LCD display during power-up. I measured 5 V at each pin for a short time instance, which matches with the power-up procedure of the LCD driver [2] mentioned on page 8.

So my conclusion is, the LCD display is damaged. By playing around with the buttons sometimes is see very dim segments corresponding with the main "numbers".
The display it self is obviously a custom one. It seems the whole LCD board (0058758037) is not available any more, further with a cost of about 200€ [3] it was outrageously expensive.

So a custom made display would be required. At hackaday.io such a project already exists [3], but nothing has happened in about 1,5 year. As these solder stations are still widely in use e.g. in my former company as well as in my current one, I think a freely available replacement display would be of use for a couple of people.

The LCD driver is conntrolled by an I²C communication, thus using the I²C commands sent by the MCU would be a good start. Unfortunately I'm not able to interpret the individual commands as the display is (more than) half blind. There is also a version of the WD1 available enabling a remote control by a PC, the WD1M. I tried to establish a remote control with my WD1 by hooking up a MAX3232 and a RS232 to USB converter (CH340). Unfortunately the power station couldn't be found, as can bee seen in the picture below. Thus I think there is a dedicted firmware required for the WD1M.

So long story short, I'm looking for the firmware of a WD1M utitilizing a PIC18F662 microcontroller. In [1] the firmware for a WD2M (PIC18F6622) is available, but I have not tried to flash it as I have not seen (and found) the schematic of the WD2M. Schematics for the WD1 are available at [1].

I want to mention that this is some kind of interesting task for me which might be useful for others. I do not really need the power station, I'm using a JBC .

Maybe someone is able to provide the required firmware as it can be easily extracted (tried it for my WD1 with a PICkit3), or can give some good tips to realize a replacement display.

@ the moderators: please move the thread if it would fit better in an other category, as it will most likely end in a project.

BR

[1] https://www.eevblog.com/forum/repair/weller-wd1-discussion-and-repair/
[2] https://www.nxp.com/docs/en/data-sheet/PCF8576.pdf
[3] https://hackaday.io/project/166744-weller-wd1-soldering-station-display-replacement

 

[stenzer]

Hi,

I was able to establish a communication between my (non M) WD1 and the WD Monitor software.

As I came across the sentence "... Mini USB interface as standard. This can retrofitted on the WD 1 control unit." on page 39 in [1], I suspected there is no need for a dedicated firmware. Thus I also tried a USB to UART IC from FTDI (FT232BL) without any success. During the installation of the WD Monitor Software [2] also the NI-VISA Run Time Support is installed, so I suspected the provided software can only be used with a certain USB to UART bridge. Is this even possible? The USB driver provided for the WD1M at [2] is for a CP210x and in an other document I have seen a CP2102 is used. I ordered a cheap CP2102 board for about 1 €. And It was a full success (so far).

The diode which can be seen in the last image is used to power the CP2102 when not connected to a PC, to avoid powering up of the CP2102 across its protection circuitry structure due to the operation of the WD1 (PIC16). I planed to place a voltage level translater between the WD1 and the CP2102 as the WD1 is using 5 V logic levels whereas the CP2102 uses 3.3 V levels. Unfortunately the supposed 3.3 V are 4.2 V(the CP2102 should provide 3.3 V according to its datasheet) and my TXB104 voltage level translater is limited to 3.6 V and 5 V at side A and B, respectively. The maximum input voltage for the CP2102 is stated with 5.8 V.

I hope this findings will help some of you, to use their WD1 at least with a PC when the display is already blind.

If I find some time I will try to record the I²C commands which are sent by the PIC16 to control the display (PCF8576). To create a replacement for the display I'm thinking about a MCU slolution, which will control a replacment display by I²C or SPI (or evena paralle approach). Maybe someone has a suitable suggestion. The original display has a size of about 70 mm x 40 mm. If powered by the single 7805 regulator (~16 VDC input), the overall current consumption should be considered.

BR

[1] https://docs.rs-online.com/5c7b/0900766b80ba7602.pdf
[2] https://www.weller-tools.com/professional/USA/us/Top-Menu/Download+Center/Software+Updates

 

[yabba236]

Hi,

I got my hands on a dumped Weller WD1 for 20 € and I thought I will give it a try, as there was no specific fault stated. After powering up it was obvious that the display is faulty. For comparison here is a picture of the display of my WD1 during power-up.
View attachment 167489

And here the picture of an fully functional WD1 during power-up.
View attachment 167490

At this point I have to mention that I also "hijacked" a WD1 repair thread at [1]. It seemed to be the right place to address this issue, but no one responded .

(i) First I had checked the 5 V supply voltage used for the MCU (PIC18F6622) and the LCD driver (PCF8576), which is good.
(ii) As there was a HEX file provided at [1], I re-flashed the firmware. No changes at the display.
(iii) I measured (with a DMM) each individual pin of the LCD display during power-up. I measured 5 V at each pin for a short time instance, which matches with the power-up procedure of the LCD driver [2] mentioned on page 8.

So my conclusion is, the LCD display is damaged. By playing around with the buttons sometimes is see very dim segments corresponding with the main "numbers".
The display it self is obviously a custom one. It seems the whole LCD board (0058758037) is not available any more, further with a cost of about 200€ [3] it was outrageously expensive.

So a custom made display would be required. At hackaday.io such a project already exists [3], but nothing has happened in about 1,5 year. As these solder stations are still widely in use e.g. in my former company as well as in my current one, I think a freely available replacement display would be of use for a couple of people.

The LCD driver is conntrolled by an I²C communication, thus using the I²C commands sent by the MCU would be a good start. Unfortunately I'm not able to interpret the individual commands as the display is (more than) half blind. There is also a version of the WD1 available enabling a remote control by a PC, the WD1M. I tried to establish a remote control with my WD1 by hooking up a MAX3232 and a RS232 to USB converter (CH340). Unfortunately the power station couldn't be found, as can bee seen in the picture below. Thus I think there is a dedicted firmware required for the WD1M.
View attachment 167491


So long story short, I'm looking for the firmware of a WD1M utitilizing a PIC18F662 microcontroller. In [1] the firmware for a WD2M (PIC18F6622) is available, but I have not tried to flash it as I have not seen (and found) the schematic of the WD2M. Schematics for the WD1 are available at [1].

I want to mention that this is some kind of interesting task for me which might be useful for others. I do not really need the power station, I'm using a JBC .

Maybe someone is able to provide the required firmware as it can be easily extracted (tried it for my WD1 with a PICkit3), or can give some good tips to realize a replacement display.

@ the moderators: please move the thread if it would fit better in an other category, as it will most likely end in a project.

BR

Can you sold this faulty board ?
I'm looking for faulty weller solder station wdxx for repair

 

[stenzer]

Hi,

only the display is faulty and I'm aiming to design a display-board by extracting the I²C commands of the soldering station (hopefully I find some time in the near future). The soldering station works even without the display, as it can be used with a PC with the mentioned modifications dicussed in this thread and shown in the picture below.



So I'm not selling my "broken" WD1. Further, I assume the shipment of the solderstation itself would cost way too much (destination country ?).

Have a look in the EEVblog [1] weller repair discussion thread, maybe someone of the guys there wants to sell his station.

[1] https://www.eevblog.com/forum/repair/weller-wd1-discussion-and-repair/50/

BR

 

[BradtheRad]

LCD displays often are connected via a 'zebra strip' to numerous copper tabs on a circuit board. If yours is similar then connections can deteriorate over time, due to tarnish or corrosion or pressure changes resulting in gaps. Some segments on the LCD disappear, while other segments are unaffected.

 

[stenzer]

Hi,

unfortunately there is no "zebra-strip-issue". The display has soldered connections, see picture below.

BR

 

[yabba236]

Hi,

only the display is faulty and I'm aiming to design a display-board by extracting the I²C commands of the soldering station (hopefully I find some time in the near future). The soldering station works even without the display, as it can be used with a PC with the mentioned modifications dicussed in this thread and shown in the picture below.

View attachment 173756

So I'm not selling my "broken" WD1. Further, I assume the shipment of the solderstation itself would cost way too much (destination country ?).

Have a look in the EEVblog [1] weller repair discussion thread, maybe someone of the guys there wants to sell his station.

BR

i.e. you do not need the display itself - will you have a problem desoldering it without overheating - I will gladly buy it - shipping to Poland.
Yes I know that it is damaged, but it displays something - mine does not display anything, so I'm looking for a replacement.

 

[stenzer]

Hi,

I'm not selling an already damaged display which does not show a single temperature digit at all, it's just not worth the work. Please have a look on the first picture in the initial post. The second picture shows a fully funtional display during power up, for comparison.

BR

 

[plus1pxl]

Have you tried cleaning the contacts between pins and glass surface?
Not sure if the contacts are on top or bottom, but if its the latter, lcd needs to be desoldered.
Preferably done with temperature controlled desoldering gun to avoid damaging the polarizers.
I believe this is how the pins are connected to the LCD.
If you are using IPO as cleaning solution, be careful not to get it on the polarizer as it would affect the UV glue and you will end up with darker spots on the screen.

 

[stenzer]

Hi,

it seems some one was faster than me with the reverse engineering of a broken display. Big thumbs up to Lauri Pirttiaho. So if someone comes across this thread, have a look here to find a proper solution/replacement.

https://hackaday.io/project/188741-replacing-broken-lcd-of-weller-wd1

BR