Weller WMA 1 station not working

Thread Starter

amerigo17

Joined Oct 19, 2021
2
My Weller WSA 1 rework station. I have the following problem:

When I turn on the power switch, the green indicator light comes on. The pump starts. This all lasts for 1 sec, at which point the main 0,8 A fuse blows.

I would like to ask for your opinion from your experience what could be wrong. At the same time I also ask for an electrical diagram of the control PCB. The details of the station are in the attachment to the letter. Thank you very much in advance for your help.
 

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dl324

Joined Mar 30, 2015
16,928
Welcome to AAC!

The unit has 2 transformers. You can try to isolate which one is blowing the fuse. Then check that transformer to make sure no windings are shorted. If the transformer checks out, look for something further downstream.
 

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Thread Starter

amerigo17

Joined Oct 19, 2021
2
Welcome to AAC!

The unit has 2 transformers. You can try to isolate which one is blowing the fuse. Then check that transformer to make sure no windings are shorted. If the transformer checks out, look for something further downstream.
Hello,

Thank you very much for your efforts in solving the technical problems of my soldering iron. I did as you suggested and found that both transformers are fine.

Interestingly, when I switch on the soldering station, the pump spins for a moment, at which point it all goes out and the main 0.8A fuse blows. I have previously disconnected the hand and foot switches of the pump from the PCB.

You have sent me the schematic, but I note that it is not the same as my station, although the catalogue numbers are the same. Is it possible to provide me with a plan for my station, whose PCB pictures I am sending.

Do you have any idea what else to check. The semiconductors are marked on the PCB pictures.

I am disappointed by the unwillingness of the WELLER manufacturer to help me.

Thank you very much for your help
 

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LesJones

Joined Jan 8, 2017
4,190
You don't say HOW you checked the transformers. Try disconnecting the secondary winding of the 34 volt transformer from the board. If it still blows the fuse then it something in the logic part of the circuit. If is toes not blow the fuse then re connect the 24 volt secondary and disconnect the wires to the pump. If it does not blow the fuse with the pump disconnected than the pump is drawing too much current.
You could also try unplugging the iron to see if it blows the fuse with the iron disconnected..

Les.
 

dl324

Joined Mar 30, 2015
16,928
Interestingly, when I switch on the soldering station, the pump spins for a moment, at which point it all goes out and the main 0.8A fuse blows. I have previously disconnected the hand and foot switches of the pump from the PCB.
Is the iron connected when the fuse blows? If it isn't, then it's the pump drawing too much current.
You have sent me the schematic, but I note that it is not the same as my station, although the catalogue numbers are the same. Is it possible to provide me with a plan for my station, whose PCB pictures I am sending.
That was something I found searching the internet. You can do the same until you find something that matches your unit.
 
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