Tool parts

[randall]

I have a Makita 3/8" drill, seems to be model 6405 I've had about 7 years. I bought it to take out an organ by dismantling it, and it had hundreds of real LOOOOONG slotted screws to remove.

I've used it a LOT, even used it to drive #10x 4" deck screws into solid wood when I re-roofed my house. Sucker has torque and never let me down!

But I went to use it the other day and the switch is broken, took the switch out and it has two electronic parts, one looks like a voltage regulator and the other I can't identify, seems one or the other must have burned out.

I go and price a new switch and it's a bit over $22 with the shipping, but get this, a brand new drill, same model is $54.99, same damn thing like the printers- inks running $60 for the set and a new printer with the inks $99.95

Nothing wrong with the drill motor/gears but it's more tempting to get a brand new one.

[TDHofstetter]

If it was seven years old, it was about due to die. That thing that looks like a voltage regulator (like a 340 or a 78xx) is a power FET (field-effect transistor). It's made of silicon, which is the heart of the problem.

Silicon, as in solid-state electronics, is not a true crystalline substance but instead a slow-moving plastic substance. It does "slump" over time, and the smaller they make the little hunks of silicon inside some little multilegged hoodad the less it has to slump before something stops working.

The "projected service life" of solid-state electronic devices - as used by electronics engineers - is ten years. You can't expect any silicon-based device to last longer than that, although a few will by virtue more of luck than anything else - and the larger & meatier the silicon "chip" inside the "package", the longer it MAY last - there also depending upon just how close they designed the nads to be to the poopchute when they designed the whole circuit.

Silicon slumping - but what about glass? That's silicon, right? Right. And it DOES slump. Sometime check out the window glass in a really old building. If you can, get the whole windowpane out where you can measure it for thickness. It's thicker at the bottom than it is at the top. Really. No joke.

That inherent demise of silicon-based electronic devices is the underlying reason that there will be NO functional antique cars of this era. There can't be. Everything in 'em is run by electronics.

Doesn't even matter if it's in service or not. The silicon will slump on the shelf just as it will if it's got electrons gushing through it.

A replacement switch - when would it have been made? At the SAME time as the one in your drill. The "new" replacement switch is really OLD unused stock... and it's got little life left.

It hurts, but when something nice but old breaks down, it's VERY often not worth fixing if it depends on electronics.

-- Tim --

Every person's handiwork
Is a self-portrait.

[TDHofstetter]

OK, that yellow dude is a capacitor. It's NOT BAD. They just don't do that. The black deallybopper on the left is what's gone away... from the looks of things, that one may be a proprietary IC (Integrated circuit) instead of just an FET - it surely contains a power FET judging from the heat sink-slash-tab on its butt end... although it's possible that the switch itself (which I suspect is hidden beneath) may contain the control goodies - in which case that black three-legger WOULD be just an FET. Thing is, though, that we'd have to know the specific details of that particular FET to make it work right. Voltage & current ratings, gain, "on" resistance, that kind of thing. Doesn't look like any of the numbers I can see would cross-reference to any other manufacturer's type numbers. Any other numbers on the backside where I can't see 'em from here? No, probably just the plain ol' black backside.

If it's an FET, anyway, then there'll be more stuff inside the switch proper - stuff that'd control how the FET turns on & off.

Makes ya long for good ol' bare-metal contacts sometimes, doesn't it? At least you could FILE that with a point file.

-- Tim --

Every person's handiwork
Is a self-portrait.

[randall]

>OK, that yellow dude is a capacitor. It's NOT BAD. They just
>don't do that. The black deallybopper on the left is what's
>gone away... from the looks of things, that one may be a
>proprietary IC (Integrated circuit) instead of just an FET -
>it surely contains a power FET judging from the heat
>sink-slash-tab on its butt end...

It looks like a regular voltage regulator to me, and with the 3 typical legs, but with the heat sink tab on it. I know just a little about electronic components but not much beyond basic identification of resistors, diode and diode color stripe values and so on.


> although it's possible
>that the switch itself (which I suspect is hidden beneath)
>may contain the control goodies - in which case that black
>three-legger WOULD be just an FET.

The switch itself is another piece, this scanned piece snaps into it, the switch simply presses down on a couple of metal contact plates, so all the guts that do anything more than make a connection is right what you see.




Thing is, though, that
>we'd have to know the specific details of that particular
>FET to make it work right. Voltage & current ratings, gain,
>"on" resistance, that kind of thing. Doesn't look like any
>of the numbers I can see would cross-reference to any other
>manufacturer's type numbers. Any other numbers on the
>backside where I can't see 'em from here? No, probably just
>the plain ol' black backside.

Likely they are propreitary stuff you can't buy at Rodio Shack, had the same issue with an RV furnace whose electronic circuit board/ignitor stated in bold letters on it: "NOT FIELD REPAIRABLE" and none of the parts were shown in the Rodio Shack catalogue either. A new board ran $100 and the company required it be installed by a qualified tech, they would not sell the part directly to the public. It was VERY difficult to install- 2 screws and 2 wires, you really need an engineer there!!!!



>Makes ya long for good ol' bare-metal contacts sometimes,
>doesn't it? At least you could FILE that with a point file.

Yeah for sure!

The switch says: "Eaton Bi-ristor USA X"

Guess I'll spring for the new drill @ $54.99

[deathwish2]

>Guess I'll spring for the new drill @ $54.99

I'd be interested to know it the 'new' drill has the same insides as the 'old' drill. With all the outsourcing and moving production lines from the U.S. to Asia, or one Asian country to another . . . designs may have changed.

[randall]

>>Guess I'll spring for the new drill @ $54.99
>
>I'd be interested to know it the 'new' drill has the same
>insides as the 'old' drill. With all the outsourcing and
>moving production lines from the U.S. to Asia, or one Asian
>country to another . . . designs may have changed.

Well, Makita like everything else I assume was ALWAYS made overseas somewhere. Japan? Taiwain?
I don't think Makita ever manufactured their products here, just distributed them?

Oh yeah the price, it PAYS to shop around, same model lowest price was $54.99 higest was somewhere around $79.95

Try THIS and get prices and much more:

http://www.powertools.com/

[randall]

>If it was seven years old, it was about due to die. That
>thing that looks like a voltage regulator (like a 340 or a
>78xx) is a power FET (field-effect transistor). It's made of
>silicon, which is the heart of the problem.

Here's a scan of the guts :)

>Silicon slumping - but what about glass? That's silicon,
>right? Right. And it DOES slump. Sometime check out the
>window glass in a really old building. If you can, get the
>whole windowpane out where you can measure it for thickness.
>It's thicker at the bottom than it is at the top. Really. No
>joke.

Yes, and wavyness too, some of my windows are that way.

>That inherent demise of silicon-based electronic devices is
>the underlying reason that there will be NO functional
>antique cars of this era. There can't be. Everything in 'em
>is run by electronics.

Well the assumption is the electronics can be switched out with new ones, but it's like taking your TV set or VCR in for repairs, the service rate minimum charge might be $75 just to look at the thing, and if a new unit of comparable type can be bought NEW for $59.95 at Walmart, who is going to bother repairing the old unit??
Years ago I had an electronic typewriter, a 5 cent transistor failed, it would have cost $60 for the service had it been out of warrantee. the whole unit new cost $99.95 or some such.

>A replacement switch - when would it have been made? At the
>SAME time as the one in your drill. The "new" replacement
>switch is really OLD unused stock... and it's got little
>life left.

Eww that sux!!! You might be right there except they still make this model, and it's sold new (or can buy reconditioned from Amazon etc for about $8 cheaper, whooppee what a savings)

How 'about a trip to Rodio Shack for a new FET and voltage regulator? Both have numbers on em, can read D473 on the yellow deal followed by maybe "+40"

How long might the motor last if I bypass both and direct connect ;)