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Forum Index : Microcontroller and PC projects : A Cautionary Tale!

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romba6

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Joined: 04/07/2020
Location: United Kingdom
Posts: 37

Posted: 03:47pm 30 Oct 2020

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I was about to do some soldering to my circuitry, attached to my breadboard, connected to the expansion socket of the MM2. Power was off to the MM2. When I turned my Weller iron on, the attached monitor (still powered) did some strange things.
When I had finished soldering I turned back on the MM and here started my problems !!
The boot logo momentarily appeared then the screen went blank, then about every 20 seconds a few error messages flashed up, just momentarily, this was repeatable. I thought maybe the surge from turning on the iron might have corrupted the Waveshare so I reflashed with vanilla V5.05.05.
This time the boot logo appeared and remained but cursor was not flashing and no input from keyboard accepted. I replaced IC1(MCP2221A) � just in case, but with no change. All power supplies OK.
I was left with no alternative but to replace the Waveshare board. This I did and was back to 100% working.
Anomolies: I could flash the Waveshare OK and with no errors, get the bootscreen up but nothing more.
Expensive Lesson Learnt: Not to plug anything, that�s liable to cause a power surge, into the same power socket as my MM2 !! As I said � a cautionary tale.

twofingers

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Joined: 02/06/2014
Location: Germany
Posts: 1593

Posted: 03:59pm 30 Oct 2020

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romba6 said attached to my breadboard, connected to the expansion socket of the MM2.

You probably mean CMM2? MM2 is IMO Micromite.

Nice story!

Regards
Michael

causality ≠ correlation ≠ coincidence

Justplayin

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Joined: 31/01/2014
Location: United States
Posts: 328

Posted: 05:08pm 30 Oct 2020

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Quote You probably mean CMM2? MM2 is IMO Micromite.

Confused me... I thought he was talking about a MicroMite 2 not a Color MaxiMite 2. Two completely different devices.

--Curtis

I am not a Mad Scientist... It makes me happy inventing new ways to take over the world!!

romba6

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Joined: 04/07/2020
Location: United Kingdom
Posts: 37

Posted: 05:44pm 30 Oct 2020

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Apologies for confusion - yes Colour MaxiMite 2 is what I was referring to !!

twofingers

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Location: Germany
Posts: 1593

Posted: 06:54pm 30 Oct 2020

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romba6 said When I turned my Weller iron on, the attached monitor (still powered) did some strange things.
When I had finished soldering I turned back on ...

I would guess the transformer for the weller is the culprit (back-EMF).
Michael

causality ≠ correlation ≠ coincidence

romba6

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Joined: 04/07/2020
Location: United Kingdom
Posts: 37

Posted: 08:13pm 30 Oct 2020

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twofingers said

romba6 said When I turned my Weller iron on, the attached monitor (still powered) did some strange things.
When I had finished soldering I turned back on ...

I would guess the transformer for the weller is the culprit (back-EMF).
Michael

Yes, that was my thought too. Never had a problem with any other kit in the room so I guess the Waveshare is quite sensitive. I will now conduct my soldering from another workroom environment viz the shed !!!!

TassyJim

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Joined: 07/08/2011
Location: Australia
Posts: 6283

Posted: 08:35pm 30 Oct 2020

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romba6 said I was about to do some soldering to my circuitry, attached to my breadboard, connected to the expansion socket of the MM2. �Power was off to the MM2. When I turned my Weller iron on, the attached monitor (still powered) did some strange things.

Soldering something that is still plugged in, even if turned off, can lead to ground loops. I suspect that that is what started your 'adventure'

Jim

VK7JH
MMedit

Tinine
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Joined: 30/03/2016
Location: United Kingdom
Posts: 1646

Posted: 08:53pm 30 Oct 2020

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FYI:
I haven't plugged my mains-powered soldering iron in for more than 18 months now, since I received my Ts80. Absolutely love this thing. I don't even use the mains USB adapter because my "turbo charge" battery pack is more convenient.

Now, just this week, I received an 8W rechargeable iron (!!!) It was less than US$20 so, what the hey.
This was an impulse purchase and I hadn't even checked-out the YT reviews.
I have to say that I am thus far very impressed. I almost replied to the spam vape thread because apparently, this soldering iron is simply a vape unit (I wouldn't know) with a soldering tip adapted.
Some reviews are negative and so now I don't care about reviews. I can make use of this thing in some of the tight spaces where even the TS80 can be cumbersome.
The problem is that one needs to keep it charged because the supplied charger can take forever and a day.

This review pretty much reflects my own sentiment:

Wireless soldering iron
Edited 2020-10-31 06:55 by Tinine

twofingers

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Joined: 02/06/2014
Location: Germany
Posts: 1593

Posted: 10:50pm 30 Oct 2020

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@Tinine
It's interesting and cheap (12� @Ali).
But I would be a little skeptical about the 14500 LiIon battery. Chinese batteries often only have 10-20% of their nominal capacity. Do you think the solder tip is usable?

causality ≠ correlation ≠ coincidence

Tinine
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Joined: 30/03/2016
Location: United Kingdom
Posts: 1646

Posted: 01:20am 31 Oct 2020

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For me, the jury is out, regarding the tip because I'm generally not a fan of the pointed tip. I have one for the TS80 but I hardly use it.

I'll test the iron on actual circuit boards over the weekend. I plan to stress test this thing and if it survives, I will go for the optional tips.

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