Motorguide mosfet repair help, please

[naneely]

I have a Motorguide Brute 765 24 volt, 50 lb thrust motor with foot control and Dura amp system. The motor when under load will not hold a steady output. The repair shop said that the "mosfet" was very likely to be the problem, and these are apparently no longer available. The shop said that I could upgrade to digital for about $400-450. (This sounds like the movie Robots where Bigwelds new CEO only wants to sell high priced upgrades!!!) Not taking this lying down, I found a string of messages that seems to indicate that these units can be repaired fairly easily according to K-dog...(http://www.wmi.org/bassfish/bassboard/boats_motors/t77809.htm)

The hard part appears to be finding exactly the right transistors. I'm willing to give the repair a try if someone out there can help me find the exact replacement transistors. I have taken the motor apart and found the transistors. I'd be very greatful if any of you would be able to help me find these items?

I found two of the following components: (I believe these are mosfet)
IRF Z44
I R4049
5L 3C

I found one of the following components: (Is this a mosfet, too?)
9040
->|<- MUR
3005 PT
(also stamped with a Motorola symbol and a "France" label)

I found a part that looks very similar and a picture that looks very similar to the first part listed above at the following site,
http://www.mcminone.com/product.asp?..._i d=IRFZ44

Does anyone have any idea exactly where I can find these replacement parts and exactly what to ask for to ensure that I get what I need?

Any help you can offer would be greatly appreciated.

Thanks,
naneely

 

[wire2]

Re: Motorguide mosfet repair help, please

I found two of the following components: (I believe these are mosfet)
IRF Z44
http://www.datasheets.org.uk/preview/1788875.html
I R4049no
5L 3Cno

I found one of the following components: (Is this a mosfet, too?)
9040
->|<- MUR
3005 PTI believe that's a diac, used to trigger the mosfets
(also stamped with a Motorola symbol and a "France" label)

I found a part that looks very similar and a picture that looks very similar to the first part listed above at the following site,
http://www.mcminone.com/product.asp?..._i d=IRFZ44

Does anyone have any idea exactly where I can find these replacement parts and exactly what to ask for to ensure that I get what I need?

Any help you can offer would be greatly appreciated.

Thanks,
naneely

The IRF44 is available at electrosonic.com for 67? each, in Toronto, Canada. http://www.e-sonic.com/acc/products.aspx?command=detail&partID=IRFZ44NPBF&partIDExt=212
I just noticed, minimum order quantity is 50.

Newark ; $1.16 ea, 1-10
http://www.newark.com/jsp/search/results.jsp?N=0&Ntk=gensearch_001&Ntt=IRFZ44&Ntx=&isGoback=false

 

[naneely]

Re: Motorguide mosfet repair help, please

Thanks wire2. You have been extremely helpful. I hope I can return the favor some day.

naneely

 

[wire2]

Re: Motorguide mosfet repair help, please

Thanks wire2. You have been extremely helpful. I hope I can return the favor some day.

naneely

My pleasure. Feel free to PM me if I can answer other questions, or post here.
Keep in mind about static precautions and heat sinking.

 

[gonefishie]

Re: Motorguide mosfet repair help, please

If you can take a picture of the components and enlarge it so we can see the label clearly, we can help you. There are semiconductor cross reference resources that can be use to match up components from difference manufacture. You don't have to have the exact one, just as long as it have the same specs.

 

[naneely]

Re: Motorguide mosfet repair help, please

I've taken a few pictures of the board in the lower end of my trolling motor, and I've attached them to this posting. I'm hoping that this will be enough information for someone to help me find exactly the electronic components that I need to replace the mosfet on my MotorGuide and save it from the trash bin.

Regards,
naneely

 

[MrBigStuff]

Re: Motorguide mosfet repair help, please

You've been given a good source for the MOSFET.

What I've found is that a Motorola MUR3005PT is a 30A fast recovery diode 300-600V. I haven't been able to find a source for it yet. Here is what appears to be a suitable replacement although I didn't spend too much time on it- http://www.onsemi.com/PowerSolutions/product.do?id=MUR3060WT

 

[gonefishie]

Re: Motorguide mosfet repair help, please

Your IRFZ44 is equivalent to NTE2395
MUR3005PT = NTE6246

Direct linking is not permitted so go to either newark.com or mcminone.com and put in the part number in the search window. I checked and both places have the NTE2395 in stock but the NTE6246 have 2 weeks lead time.

 

[naneely]

Re: Motorguide mosfet repair help, please

Thanks everyone for the help. I've place the parts order. I'll check back in after I've soldered my new components on and let you know how it worked out. If I can get this to work I'll post a how-to on this site for anyone else who might run into the same problems I have

naneely

 

[groves1955]

Re: Motorguide mosfet repair help, please

Were you able to fix your trolling motor w/ the mosfet? I seem to be having a same type of problem.

 

[TerryMSU]

Re: Motorguide mosfet repair help, please

Thanks everyone for the help. I've place the parts order. I'll check back in after I've soldered my new components on and let you know how it worked out. If I can get this to work I'll post a how-to on this site for anyone else who might run into the same problems I have

naneely

I work with these types of part all the time, and so i have a couple of tips that may help you prevent some issues. Mosfets are very sensitive to static electricity. To reduce the risk, there are a few tricks to use.

1. Reduce your static electricity. Cotton, not synthetic clothes. Use static guard, etc. and/or fabric softener on your clothes.

2. Temporarily short out the leads on the mosfet with a piece of aluminum foil. Remove the foil after you solder the new part in.

3. Use the right type of solder iron (not a gun). Ideally, the iron should have a grounded tip. If it does not have a 3 wire plug, it is not a grounded tip. Wrap a wire around the tip, and run it to ground (the round wire in the wall socket).

A tip on removing the old part. Cut the individual leads on the part. then heat and remove them individually.

Solder. Do not use plumbing solder. Especially do not use plumbing flux. Buy some rosin core solder. It will have flux inside the solder. Clean the joint with some acetone to remove the flux when you are done. The flux can be an issue in a wet environment.

One other thought. Install the diode first. It is much less sensitive to static than is the MOSFET.

By the way, my inclination is that the MOSFET is the more likely part to fail.

Good luck.

TerryMSU

 

[mplsman50]

I know this is a very old thread but.... Does anyone have the part number for the mosfet on a Motorguide Tour TR109FB? It's the 36volt variable speed non digital. I would like to resurrect it from the infamous stuck in high speed only syndrome. I can add photos if anyone needs them. I know electronic parts are out there and I can do mosfet repair, I just need some part numbers. Any help would be appreciated. I have replaced my unit with a digital model but still want to get this one working if possible.

 

[mplsman50]

Hopefully people still read these....

 

[GA_Boater]

I know this is a very old thread but.... Does anyone have the part number for the mosfet on a Motorguide Tour TR109FB? It's the 36volt variable speed non digital. I would like to resurrect it from the infamous stuck in high speed only syndrome. I can add photos if anyone needs them. I know electronic parts are out there and I can do mosfet repair, I just need some part numbers. Any help would be appreciated. I have replaced my unit with a digital model but still want to get this one working if possible.

Hopefully people still read these....

Mods read the old threads that are reopened by other than the Original poster (OP).. Please read this before you start a new thread on your TM problem - Forum Rules

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