Printed board blown of Metabo planer, can it be fixed

Simon Bates

Joined Nov 30, 2018
3
Hi all, I am trying to build a new career following years of ill health. Its woodworking. I recently made a big outlay for me on a planer/thicknesser. The printed board behind the on/off switch had blown (Pictures attached). I have fixed hairdryers/washing machines etc and soldered some boards on consumer stuff in the past. There is a brown burn mark behind the three thingy's to the top left of the board in the first picture(they run left to right and are kinda framed by the brown wire. Anyway, 1st problem, what are they, 2nd where do I by them, 3rd quest do I just replace them them and hey presto it should work... or do I need every component checked? Thanks in anticipation and kind regards people. By the way,the manufacturer wants £125 for a new switch... something io simply could not afford.

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dl324

Joined Mar 30, 2015
8,849
Welcome to AAC! Good luck with your endeavor.

I bought some woodworking equipment (contractors table saw, bandsaw, radial arm saw, thickness planer, dust vacuum, jointer). I was planning to get into woodworking after recovering from a motor vehicle accident that caused me to retire. That was 5 years ago and I'm still recovering (or maybe not).
There is a brown burn mark behind the three thingy's to the top left of the board in the first picture(they run left to right and are kinda framed by the brown wire. Anyway, 1st problem, what are they,
Post a clearly focused close up of the area around the burn mark.
2nd where do I by them,
Do you have any local stores that sell components? If not, order online.
3rd quest do I just replace them them and hey presto it should work... or do I need every component checked?
You'll likely need to check more components unless the component that died didn't take anything else with it. I noticed a fuse, that may be blown.
Thanks in anticipation and kind regards people.
Some constructive criticism (and I don't intend this to be snarky), but your posts would be easier to read if you use paragraphs to organize your thoughts.
By the way,the manufacturer wants £125 for a new switch...
I paid $125 for my 13" planer used. It would be helpful if you traced the circuitry and posted a schematic. MaxHeadRoom Joined Jul 18, 2013 18,995 I suspect the AC power goes into the other board, if so this is probably all low voltage on the board in question, as it requires L.V. for the Hex flip-flop IC. etc. What you need to do is get a feel for the different purposes of the two boards, IOW, measure some voltages and get a feel of what is needed, generally in the absence of a schematic it take some reverse engineering to trace the problem. Max. Thread Starter Simon Bates Joined Nov 30, 2018 3 Welcome to AAC! Good luck with your endeavor. I bought some woodworking equipment (contractors table saw, bandsaw, radial arm saw, thickness planer, dust vacuum, jointer). I was planning to get into woodworking after recovering from a motor vehicle accident that caused me to retire. That was 5 years ago and I'm still recovering (or maybe not). Post a clearly focused close up of the area around the burn mark. Do you have any local stores that sell components? If not, order online. You'll likely need to check more components unless the component that died didn't take anything else with it. I noticed a fuse, that may be blown. Some constructive criticism (and I don't intend this to be snarky), but your posts would be easier to read if you use paragraphs to organize your thoughts. I paid$125 for my 13" planer used.

It would be helpful if you traced the circuitry and posted a schematic.

I will take some clearer picture.. Thanks for the prompt reply and good luck with your health.

dl324

Joined Mar 30, 2015
8,849
Thanks.

Are the three resistors circled in red what you were referring to as burned? Three 56k resistors in parallel.

I noticed discoloration from the bottom of the board, but it doesn't look like any of the resistors opened up.

MrChips

Joined Oct 2, 2009
19,269
Welcome to AAC!

Here are some things you can do ahead of posting in order to help us help you.

Post the brand and model number of the unit.
Search online for a User Manual, Service Manual, and best of all, schematic drawings.
Post clear well focused photos of all electronics boards involved.
State the history of the unit.
Was it working when you go it?
When did it stop working?
What were the circumstances when it stopped working?
Did you witness smoke, burnt smell, etc.?

Simon Bates

Joined Nov 30, 2018
3
Help needed with electrics on a Elektra Beckum Planer Thicknesser HC 260. I took a chance a bought this machine with a blown switch. A replacement is approx £125, which is beyond my means at present. I have pictures of the offending circuit board and the three resistors that appear blown. Whilst I no nothing about them i would be able to remove and solder three replacements but would this be enough? If these are blown would components near them need to be changed, how do test them? Any help would be appreciated.

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JSCV

Joined Oct 3, 2015
22
Those resistors indeed look a little crisp, but it doesnt seems to be instant damage, more like that they were warm for a longer period of time.
You could use a multimeter to measure if they are still ok or not. This circuir board doesnt seem to difficult to trouble shoot.
Start with measuring the Fuse, and the burned resistors. if they are ok, start measuring the supply rails and work your way trough the board.
All the components seem regular and easy to get.

dl324

Joined Mar 30, 2015
8,849
If the fuse is still good, trace the board and post a schematic.

Why did you start a new thread?

LesJones

Joined Jan 8, 2017
2,316
The first post is a bit confusing. You said the iten was bought with a "blown switch" Can we assume that you have fixed that fault but you now have another fault ? Looking at the board it appears that the three reasitors are part of the power supply for the electronics. I think the push on connector marked L2 is one side of the mains input. This is rectified by the diode just to the right of the three resistors and these resitors drop the voltage to what I tink is a zener diode just to the left of the group of resistors. I think the electrolytic capacitor is in parallel with the zener diode. I suspect that there is nothing wrong with these resistors. I think that they just normally run at a high temperature as they will disipate quite a lot of power. Do you get a DC voltage across the zener diode about equal to it's voltage rating ? (I would expect beween 5 and 12 volts.)

NOTE I started typing this reply in the duplicate threat which I think has probably been closed.
Les.
MOD:
hi Les.
The 2nd Thread posts have been Merged with this one.

Last edited by a moderator:

ebp

Joined Feb 8, 2018
2,332
The circuit is very unusual for something that would be just on-off control.

Is the switch supposed to change the speed of the planer in some way, or just turn it on and off? Are the jumpers (the arrangement of little square pins in the lower left corner of the board) supposed to set a fixed some operating speed that is controlled by the on/off switch or perhaps set a running time (e.g. you turn the motor on and it shuts off automatically after some time interval)?

dl324

Joined Mar 30, 2015
8,849
Around here, we'd call that a jointer:

So the attachment on the top turns it into a thickness planer?