Reviving another free mower: Black and Decker corded LM110 (rectifier)

MetroMPG · 06-24-15, 02:03 PM

These things seem to find me like stray kitties:

This is an AC (corded) Black and Decker LM110 lawnmower that a neighbour rolled out to the curb a couple of weeks ago.

"What's wrong with it?"

"I dunno. It quit working half way through cutting the lawn."

They're ridiculously un-complicated. Even not knowing what was wrong, there are only a few possible culprits:

- switch (most likely culprit)
- wiring
- motor brushes
- rectifier/diode
- ??

Also, I already have one exactly like it, so I couldn't resist. It's light and has been dead reliable (except the metal where the wheels join the body is weak).

Specs:

Model: LM110 04/80 (probably date of manufacture)
Type: 2
7 Amps

Made right here in my small city, before the B&D plant closed down.

--------

First I took apart the handle/switch to test for current with a multimeter. The switch was fine; juice was getting through.

Next I took off the motor cover, and AHA! Here's our problem (bottom):

These are bridge rectifiers that convert AC electricity into DC that the motor needs. Top: replacement; Bottom: looks like something blew and the terminal burned up.

Rectifier part number (MP254 / V408) led me to eBay where I bought the silver replacement -- KBPC-2510 Bridge Rectifier 25A 1000V.

$1.88, shipped. Delivery from China took a couple of weeks.

Here it is installed:

I put everything back together, plugged it in ... and it whirred back to life! Another mower saved from the crusher!

Hopefully this new rectifier lasts 35 years like the first one.

It gets warm to the touch after just a few minutes -- I haven't cut the entire grass yet, but I have sharpened the blades and will try it out. Will report back!

06-24-15, 02:03 PM	#1
MetroMPG Infrequent noob Join Date: Aug 2008 Location: 1000 Islands region, Ontario, Canada Posts: 402 Thanks: 37 Thanked 20 Times in 19 Posts	Reviving another free mower: Black and Decker corded LM110 (rectifier) These things seem to find me like stray kitties: This is an AC (corded) Black and Decker LM110 lawnmower that a neighbour rolled out to the curb a couple of weeks ago. "What's wrong with it?" "I dunno. It quit working half way through cutting the lawn." They're ridiculously un-complicated. Even not knowing what was wrong, there are only a few possible culprits: - switch (most likely culprit) - wiring - motor brushes - rectifier/diode - ?? Also, I already have one exactly like it, so I couldn't resist. It's light and has been dead reliable (except the metal where the wheels join the body is weak). Specs: Model: LM110 04/80 (probably date of manufacture) Type: 2 7 Amps Made right here in my small city, before the B&D plant closed down. -------- First I took apart the handle/switch to test for current with a multimeter. The switch was fine; juice was getting through. Next I took off the motor cover, and AHA! Here's our problem (bottom): These are bridge rectifiers that convert AC electricity into DC that the motor needs. Top: replacement; Bottom: looks like something blew and the terminal burned up. Rectifier part number (MP254 / V408) led me to eBay where I bought the silver replacement -- KBPC-2510 Bridge Rectifier 25A 1000V. $1.88, shipped. Delivery from China took a couple of weeks. Here it is installed: I put everything back together, plugged it in ... and it whirred back to life! Another mower saved from the crusher! Hopefully this new rectifier lasts 35 years like the first one. It gets warm to the touch after just a few minutes -- I haven't cut the entire grass yet, but I have sharpened the blades and will try it out. Will report back! Attached Thumbnails __________________ . To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.