Trouble Shooting ??'s-M-12V Speed Control

[Norman Hitt]

My M-12V has been acting up for the past few days, ie; when the cut/load was finished, as the speed control attempted to control the rpm's acceleration, it would just cut it off completely, but if you got a load back on it quickly, it would pick back up and continue to run. Then it would quit for a little while and after much fiddling, it would go again, kinda like a thermal protection shutdown. It was getting plenty of voltage though, (no extension cord) and 122V measured at the outlet. It did not feel hot, and did not have any burnt smell. I had it in the shop once before for this about a year ago, and they couldn't find anything, as it started working perfectly while there, (I bought this unit as a Factory Reconditioned unit about 3 yrs ago) and maybe that was the problem then.

Knowing an intermitant electronics problem can be a frustrating , (and sometimes costly) endeaver to find, I decided to just run it til it finally quit, and then seek a solution. Welllllllllllll...Today was the day, as it would not start from the very first try, and has remained DEAD no matter what I did.

I have thus far, done the following:
1. Removed the top and blew out all, (very little dust) from the top toward the base. (shined a light through it, and it's clean as a pin)
2. Checked continuity of both of the cord's wires from plug to switch, then plug on through the switch to the load side.
3. Removed the switch and checked the contacts, (they were fine, & no dust at all, but I polished them anyhow)
4. Checked, but could not get any continuity on the large wire on the load side of the speed control unit, but did get continuity on the small wire, which I suspect, is the feedback wire. (see note below)
5. Checked the brushes and looked into the hole to check the armature, and everything looks good.

Note: Since I don't have a schematic of the speed control, and it is a potted unit, I'm not sure if my continuity check was even valid.

My question is this; Does anyone know how to check the speed control with an ohm meter properly, OR, is other equipment necessary to check this unit?

Note 2: During my tests, I rotated the speed control throughout it's full range of settings, but no effect was noted in any of the checks. I did not want to disassemble the router any further to try to check the armature.

The "GOOD" service shop here, is usually 4 to 6 weeks behind, but if I knew for sure it was the speed control unit, I could order one and it would be a simple matter to change it out.

Any Ideas or similar experience, and solution, anyone????????? I really don't want to have to put my DW-625 back in the RT to finish this project if I can possibly avoid it.

Thanks for your thoughts.

[Ralph Steffey]

There should be a wire going in and a wire coming out of thr speed control just short across them and it should run wide open if it does then you know it the little potentometer

[Norman Hitt]

There should be a wire going in and a wire coming out of thr speed control just short across them and it should run wide open if it does then you know it the little potentometer

Actually, Ralph, there are three wires. IIRC, a heavy black, heavy white, and a smaller ga off white, and that's the one that had me concerned about shorting across the two heavier wires, what do you think, leave it connected or cut it, or what?

[Dan Clark]

Norman,

If you fix it cheaply, that's great. OTOH, if you'll need to spend some substantial bucks to fix it, you may want to consider buying a new one.

I just bought a new one on Amazon yesterday (May 17th) for $156.67 including tax and shipping (free) with a 10% discount. That breaks down to:

M12V $159.99
Shipping Free
Discount -$16.00
Tax $12.68
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Total $156.67

I pay sales tax since I'm in Washington State (Amazon is here). You may not have to. So, your cost may be something like $144.

If the cost to fix the M12V is substantial, you might find it more cost-effective to buy a new one. Note that the discount expires on May 22.

Best regards,

Dan.

[Jim Becker]

Did you blow out any dust?

[Norman Hitt]

Did you blow out any dust?

Jim, there was very little dust anywhere inside the housing, (definitely not enough to restrict the cooling airflow), and NONE inside the switch. The speed control is a potted, (sealed unit) so there cannot be any dust inside it. There is no burnt smell or discoloration anywhere inside when I shine a bright light in there, so unless there was a flaw in the windings or the armature when it was built, I don't think there is a problem with either of those. I really suspect the problem is in the speed control unit.

Dan, it's amazing that they have been having sales for a while now and selling them new for the same price I paid 3 yrs ago for the ReConditioned unit. I would have already bought another one, Buuuuuut.....this month isn't a good one for me, since I kinda took a little too much advantage of a few sales on other need shop items over the last three months, but thanks for the heads up anyhow.

[Norman Hitt]

Dan, where did you find the $16 discount at Amazon? All I see is just the $159.99 but no mention "Anywhere that I looked" about the ADDITIONAL $16 Discount. Is there a Discount Code, or is it just something that they automatically apply when you go to checkout?

(I checked the speed control price and it was $88.76 + tax (.0825% here =$7.32) makes the part $96.08). If I can get a new M 12V for the $143.99 with free shipping, it would only be $47.91 more (no tax from Amazxon here) than a new speed control, which they said would take 2 weeks to get here.

PS: Maybe someone knows a place to get better prices on Hitachi parts?????

[Hoa Dinh]

...where did you find the $16 discount at Amazon? All I see is just the $159.99 but no mention "Anywhere that I looked" about the ADDITIONAL $16 Discount. Is there a Discount Code, or is it just something that they automatically apply when you go to checkout?
...

PS: Maybe someone knows a place to get better prices on Hitachi parts?????

Use the promo code "MAYPOWER" to get 10% off the order.

I read several reports about the failure of the speed control unit in the M12V. In every single case that I know, the owner ended up either bypassing the speed control unit, or buying a new router. Noone I know has bought and replaced the speed control unit.

[Dan Clark]

Enter "MAYPOWER" in the discount field.

I'm looking forward to my M12V. It's my first router. The majority of reviews give it a thumbs up.

I'm going to use it as a hand router for an upcoming project in about two weeks. Then, I'll build or buy a router table, install it there, and buy a Festool OF 1400 EQ for hand use.

Good luck with you decision.

Best regards,

Dan.

[Rick Christopherson]

If you have an open circuit on the variable speed control resistor, the controller won't have a reference frequency and won't run. Check the connections between the speed dial and controller package. If the dial is soldered directly to the controller, try wiggling it to see if one of the posts has broken (very common). As a last resort, short the wires to the resistor and see of the motor goes to full speed.

Also check for continuity across the power switch.

Trace the incomming wires from the power cord. One of them will go directly to one of the motor brushes. The other will go through the electronics. Bypass the electronics and connect power directly to the other brush. This will confirm if the motor is operable.

[Norman Hitt]

Unless I missed some fine print somewhere, according to the little sidebar about Hitachi warranties, (on the Amazon Site), the Routers, incl the M 12V, (and SOME other Hitachi Tools), now have a "5 year" warranty. Have I missed something somewhere, because if that is correct, then it makes it a NO BRAINER to buy a new M 12V instead of a new speed controller for the old one, because I'm sure the warranty on the new speed controller would be less than 5 years.

[Norman Hitt]

About the time I got all the information, (noted in my post above), some other things came up that I HAD to attend to, and I didn't get another chance to get back on the Amazon site until a few minutes ago. I had decided to just cancel the WWII order that has been on back order for 2 1/2 months and still not shipped, and go ahead and order a new M 12 V to replace the old one. I started to check the M 12 V site again, but since I had just looked it up this afternoon, and wanted to be sure the WWII hadn't shipped yet, I went to my order site first, and while there I went ahead and cancelled the order for the WWII, then I went to the site to order the Router, only to find that it had gone up $40 (from $159.99 to $200.39), since late afternoon. Needless to say, I DID NOT place an order. I guess for the time being, I'll just forget the whole dern thing. Definitely "NOT" A GOOD DAY in Blackrock/(Odessa) I'm sure not going to read my "Horror"scope, 'Cause I don't EVEN want to know what's coming next.

[Curt Harms]

I haven't seen a ship date, but it's supposed to be table friendly. Larger base opening, (though I haven't been limited by the FT2000E's base opening) integral above-the-table height adjustment. I've had excellent luck with my FT2000E.

Assuming the problem is indeed the speed controller, could You run the motor leads through one of the $20-$30 external speed controllers? I'm sure they're not as good as the integral speed controllers, but would that provide an interim solution? They may be hard on the motor, but if you're gonna trash it anyway...

Curt

[Dan Clark]

About the time I got all the information, (noted in my post above), some other things came up that I HAD to attend to, and I didn't get another chance to get back on the Amazon site until a few minutes ago. I had decided to just cancel the WWII order that has been on back order for 2 1/2 months and still not shipped, and go ahead and order a new M 12 V to replace the old one. I started to check the M 12 V site again, but since I had just looked it up this afternoon, and wanted to be sure the WWII hadn't shipped yet, I went to my order site first, and while there I went ahead and cancelled the order for the WWII, then I went to the site to order the Router, only to find that it had gone up $40 (from $159.99 to $200.39), since late afternoon. Needless to say, I DID NOT place an order. I guess for the time being, I'll just forget the whole dern thing. Definitely "NOT" A GOOD DAY in Blackrock/(Odessa) I'm sure not going to read my "Horror"scope, 'Cause I don't EVEN want to know what's coming next.

Norman,

Hi. Check on the M12V at Amazon several times a day. The price jumps around. Right now, I'm seeing it at $127.99. When you see a price that you like, place the order immediately and see if the order is placed.

Remember to add the discount keyword.

Best of luck,

Dan.

[Norman Hitt]

Norman,

Hi. Check on the M12V at Amazon several times a day. The price jumps around. Right now, I'm seeing it at $127.99. When you see a price that you like, place the order immediately and see if the order is placed.

Remember to add the discount keyword.

Best of luck,

Dan.

Thanks a million for the Heads Up, Dan. As Soon as I saw your post, I jumped on the Amazon Site, and Wah...Laaaaaaah! Needless to say, "I Ordered IMMEDIATELY", and was thinking that I was sure glad that I didn't order last night. Below is the Confirmation e-mail, My day/week has DRASTICALLY Improved thanks to your Alertness and HELP. Hope I can return the favor sometime.

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Total for this Order: $115.19
Shipping Method: Two-Day Shipping
Shipping Preference: Group my items into as few shipments as possible
Subtotal of Items: $127.99
Shipping & Handling: $0.00
Promotion Applied: -$12.80

------
Total for this Order: $115.19

Shipping estimate for these items: May 22, 2006
Delivery estimate: May 24, 2006 1 "Hitachi M12V 3-1/4 HP Electronic Variable Speed 1/2" Plunge Router"
Tools & Hardware; $127.99

Sold by:Amazon.com