# Did I fry my LMS min-mill Power Supply



## AFCarbon15 (Mar 22, 2015)

And if I did, what are my options?  

I was running my LMS 3900 with a 3/4 EM in 7075 when it bound up from feeding a little too fast.  The mill went into the "fault" mode which is normal.  I hit the stop switch and then the start switch as normal, but, when it started up, it ran a little, then stopped and started a couple of times before it spun up to speed.  I had just hogged out a 3x3x1 area by peck drilling 1/8 through 1/2 drills then a little clean up of those holes with a 3/8 rougher before stepping up to the 3/4EM.  So, it could have been a bit hot.  It was late and I was getting tired anyway, so I figured maybe it was just a bit to hot from running most of the day.  I haven't been able to get back to the shop to see what issues may be remaining, but I'm wondering if I fried my power supply.  If I did, what are my options besides ordering another that may fry the same.  I've read of a few that used supplies from treadmills, but all were old threads.  If I did indeed fry it, I'm sure I'm not the only one.  

Options?

TIA


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## Tin Falcon (Mar 22, 2015)

Intermittent Issues  sounds like cold solder joint maybe around the mosfets. 
If you are handy with a soldering iron examine the board with a magnifying glass and resolder the cold broken solder joints .  

oftion 2 send the board for service. 
Gerling labs will repair the board for a flat rate of $ 50 plus shipping charges. 
http://www.repaircontrol.com/

3 Little machine shop .com should have a replacement board. If you want to buy new.
tin


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## chucketn (Mar 23, 2015)

There is also Peter Brush, at http://olduhfguy.com/#. No connection, have not used his service. Saw his link posted on a forum and made note of it.

Chuck


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## barnesrickw (Mar 23, 2015)

I'm not recommending this, but I have a friend who repairs computers.  He has placed the boards in the oven to re-solder connections on boards.  Takes the right temp and good timing I guess.


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## DJP (Mar 23, 2015)

Even before you check for cold solder joints, I would check wire connectors everywhere on the machine. I found a few loose and some that needed solder to make secure. I also had a failed speed control pot. The on/off switch was intermittent. I eventually replaced it with a pot and separate on/off switch. Since then no issues.


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## AFCarbon15 (Mar 24, 2015)

DJP said:


> Even before you check for cold solder joints, I would check wire connectors everywhere on the machine. I found a few loose and some that needed solder to make secure. I also had a failed speed control pot. The on/off switch was intermittent. I eventually replaced it with a pot and separate on/off switch. Since then no issues.



Well, I found some time yesterday, turns out that's exactly what it was.  the Z axis travel moving the wires loosened a connection in the control box on the back of the mill.  it wasn't obvious at first because the head had to be in the right orientation to cause the issue.  All is well now though.  I did find there are several options to swap out with electric scooter parts, motors and controllers.  Or even some RC products.  I will look into those options some time in case I have problems in the future. 

Thanks for the help.  

On a side note, I tried to reply to this on my phone yesterday but it didn't post.


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