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BobDevries

Senior Member

Joined: 08/06/2011
Location: Australia
Posts: 266

Posted: 07:48pm 23 Oct 2017

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Hi all,
Some month ago, I purchased from SC their kit Micromite+ Explore100 TFT, thinking that I should be able to do the soldering of the SMD parts myself. I was partly right, and the smaller parts were done fairly easily, but the 100 pin PIC chip evaded my attempts to "get it right". I bought another, to try a different approach, but to no avail. Sadly, my handshake is getting worse, and I don't expect to be doing SMD parts again, and even normal through-hole stuff is borderline.

My question now is: Is there someone here who could fix my stuff-ups?

One of the boards has only been soldered at the corners, but the other is a bit of a mess, but hopefully not beyond repair.

Regards, Bob Devries

Bob Devries
Dalby, QLD, Australia

Grogster

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Joined: 31/12/2012
Location: New Zealand
Posts: 9749

Posted: 08:23pm 23 Oct 2017

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I can help, if you don't get any other offers from Aussie.

Critically, have any of the SMD pads for the 100-pin chip lifted, or are they all still stuck down to the PCB?

Smoke makes things work. When the smoke gets out, it stops!

skyv
Newbie

Joined: 14/03/2015
Location: Australia
Posts: 14

Posted: 11:30am 24 Oct 2017

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I've assembled a couple of these and can have a look at yours if you like.
Unfortunately I'm in Victoria so you'll have to post them.
Let me know.

Skyv

BobDevries

Senior Member

Joined: 08/06/2011
Location: Australia
Posts: 266

Posted: 12:55pm 24 Oct 2017

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Hi Skyv, I'm in country Queensland, so I'd need to post anyway.

The pads look ok, certainly on the second board. I suspect that the first board, which is fully populated, may need some sort of heat source (hot air gun?) to lift the PIC and re-position it.

Regards,

Bob Devries
Dalby, QLD, Australia

Grogster

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Joined: 31/12/2012
Location: New Zealand
Posts: 9749

Posted: 01:06pm 24 Oct 2017

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So long as the pads for the chip are intact and have not lifted from the board, then any suitable SMD tech from Aussie will be able to fix it for you I am sure.

If any of the pads have lifted, the board is basically a write-off, because the pads are tiny, and the tracks to the pads are only 0.2mm so usually if a pad has lifted, the track has been broken and it is more trouble then it is worth to try to repair a broken PCB with thin tracks like that.

Smoke makes things work. When the smoke gets out, it stops!

Boppa
Guru

Joined: 08/11/2016
Location: Australia
Posts: 816

Posted: 01:57pm 24 Oct 2017

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Not always Grogster, I have repaired broken tracks/lifted pins in the past using ultrafine enameled winding wire (0.1/0.2mm), solder one end to the leg and the other to the track further back/at another component leg

As you may imagine, its not easy to do and requires a stereo microscope and a very steady hand, but it is possible

Grogster

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Joined: 31/12/2012
Location: New Zealand
Posts: 9749

Posted: 02:28pm 24 Oct 2017

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You're braver then me!!!

Smoke makes things work. When the smoke gets out, it stops!

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