MOSFET Switch rebuild or digital conversion

[firefltmedic]

Does anyone know if a MOSFET switch can be taken apart and rebuilt, or will I have to switch a motorguide trolling motor over to digital?

 

[TerryMSU]

Re: MOSFET Switch rebuild or digital conversion

Does anyone know if a MOSFET switch can be taken apart and rebuilt, or will I have to switch a motorguide trolling motor over to digital?

With the right soldering equipment, they almost certainly can be rebuilt (This assumes there is not too much damage to the board, and that a similar MOSFET is available.) To be honest, the fact you are asking this question says that you probably do not have the right equipment. The right equipment will cost a minimum of $50. Then you need to know how to do electronic soldering.

TerryMSU

 

[firefltmedic]

Re: MOSFET Switch rebuild or digital conversion

I have plenty of equipment available to use, and have done electric soldering before. After troubleshooting the board in the top housing of motor, it tested out fine.

 

[gm280]

Re: MOSFET Switch rebuild or digital conversion

With the right soldering equipment, they almost certainly can be rebuilt (This assumes there is not too much damage to the board, and that a similar MOSFET is available.) To be honest, the fact you are asking this question says that you probably do not have the right equipment. The right equipment will cost a minimum of $50. Then you need to know how to do electronic soldering.

TerryMSU

First of all, how do you know the MOSFET is the problem? If you know absolutely the MOSFET is shorted or open, then you know enough to be able to change it successfully too. But I would certainly not change it with the exact same part number. WHY? Because if it shorted or opened once then chances are the next one will do the same...eventually. So I would go up in the current capability if I were doing the replacement. MOSFETs are not that expensive, in fact they are very cheap to replace. If you research the original MOSFET and it can handle say...30 amps, I'd replace it with one that can handle 40 or 50 Amps. The MOSFET packaging is the same for higher current capabilities also. BUT, you may have to add some more heat sink capability as well. Heat will destroy parts quicker than anything else... If the actually PC board has any damage you can easily clean any and all charred board out and use epoxy to make a smooth repair to the board itself. Then just run wires to and from the component if you don?t have a circuit board repair kit to replace the runners. I?ve done it many times before and it is a legal and certified board repair even for the DOD...

 

[firefltmedic]

Re: MOSFET Switch rebuild or digital conversion

Please reference the link to understand what is being discussed. This is how I know the board is good. http://www.**********/parts/search/...sembly(67# - Variable) (MUF397072)/parts.html
The item in question is #7 on the parts list. The board is in the controller head on the top of the motor.

 

[NYBo]

Re: MOSFET Switch rebuild or digital conversion

The link has been automatically edited by the forum software to eliminate the name of an iboats competitor, so we can't see the part in question.

 

[dwparker99]

Re: MOSFET Switch rebuild or digital conversion

I just changed out the rectifier (NTE6246) and two Mosfet transistors (NTE2395) on an old motorguide 765 Brute series TM. The electronics parts cost about $25 and $25 for the seal kit. The soldering was a little tedious but not to bad. Mine would run on high bypass only until I changed out the parts. It works fine now out of the water. Haven't had a chance to test on the water yet. I think I killed mine by running a lot on the high variable speeds. If I need to run on high in the future, I will run on high bypass to keep from heating up the mosfet components.

 

[firefltmedic]

Re: MOSFET Switch rebuild or digital conversion

Here is a different link since the previous link didn't work.
https://docs.google.com/file/d/0B_sGChBQJR9VWWkzcDZkajY4Tk0/edit?usp=sharing

 

[TerryMSU]

Re: MOSFET Switch rebuild or digital conversion

I have plenty of equipment available to use, and have done electric soldering before. After troubleshooting the board in the top housing of motor, it tested out fine.

But have you done ELECTRONIC soldering? That said, give it a try. At a minimum you need the capability to solder with a grounded tip soldering iron. Controlled temperature would be nice. For MOSFETs, ESD (Static damage) is a big issue. High humidity and tying yourself and the unit to earth ground will help with that. Finally, unless you are using "no-clean" solder and flux I would recomend cleaning the connection with some sort of solvent (perhaps acetone) to remove flux residue. The flux residue is slightly acidic and will eventually eat the traces right off the circuit board. Remember that acetone is highly flamable, so give it quite some time before you use it to power up the motor. The brushes on the motor will set the acetone off. (Don't ask me how I know, but it was exciting.)

PS: If you were a little closer, I would be glad to help.

Good luck,
TerryMSU