Weller WR3M - Port 1 Repair

[JagerBombastic]

Hello,
I have a Weller WR3M rework station and the first port no longer works.

I can plug the vacuum and hot air tools into port 2 and 3 and they work fine but neither work on port 1.
It seems like it is no able to detect the tool. I have checked the internal lead that connects the port to the main board and it checks out fine and there is no visible faults on the board.
When probing around with a voltmeter I can see that on pins 1 and 2 of the port connectors on the main board I get around 2.3v on the port 2 and 3 connectors and 2.6v on port 1 so I wonder if this is related to the issue.

i'm sure someone else has has this issue before so i am hoping to get some advice on how to fix it.

Thanks in advance,
Thomas

[Popeye]

Fuses are okay?
There are SMD Fuses on each MOSFET (mounted on the heatsink) which are dedicated to the different ports.

[JagerBombastic]

Thanks for the suggestion, though I have tested all of the fuse and the all seem fine.

[peter2]

There are is a diode  leak on the board 
Iam Sure i read it  geforensden on www.circuitsonline.nl
Have I Nice repair

[Smith]

Only repair I ever did on a WR3M was replace the TRIAC's or MOSFET's. I think it where BT16-600 of equivalent. In my case they where shorted, so the heating element was heated up until destruction. I simply replaced the faulty ones (I think there where 2 or 3 defective) and after about 5 years it's still working. Maybe they opened up in your case?

Also check all the fuses, I've blown some before in WD2M stations for no apparent reason.

Have you tried setting it from the PC via the USB port with the Weller WD monitor software? Not entirely sure it works with the WR3M though. I had trouble with a few WD2M stations that had a single output that would not work. It could not be enabled with the front controls (line holding the up and down to enable / disable the port). Only disabling and enabling it and playing with some of the features made the port work  again.

[brump]

Hello,

I had the same problem with my WR3M rework station on channel #1.

After searching, I found the flaw.
The V8 varistor that is connected between the pin that takes the signal from the HPA200 iron button and the ground, as shown in the attached image. The varistor has low insulation. It didn't close short, but its resistance was around 7K ohms. While the others have 220k ohms.

As I don't know the correct voltage for it, I removed it from channel 3 and soldered on channel 1, because channel 3 I leave the soldering iron straight and not this line is not used.

After that the wr3m is operational!

Cheers,
BP