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Author Topic: 12v Charger PCB blowing fuses  (Read 7289 times)

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stevepo

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Re: 12v Charger PCB blowing fuses
« Reply #15 on: November 02, 2012, 12:21:30 PM »
Hi, thanks for your continued help!

This evening i will check D13,14,16 and Q2.

When you say Big white thing on the left, do you mean on the first picture, inbetween the + and - terms? that says LL GET on it. i think its a fuse? maybe thermal reset? what do you think?
i will take a closeup of it, if thats the component you are talking about.

thanks.

oh, also i did actually test D13,14,16 quickly last night, but these were whilst in the board, so my values may be off. it was strange, because they looked the same, 2 of them gave a reading of around 200, and one of them said 600... but maybe that was because its still in hte board, maybe getting a iffy value from somewhere, so ill try them out the board later.
« Last Edit: November 02, 2012, 12:28:49 PM by stevepo »

cheerio

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Re: 12v Charger PCB blowing fuses
« Reply #16 on: November 02, 2012, 20:04:40 PM »
On board checks are ok for quick checking. I usually look for high impedance or shorts while on board checking. if a component has a weird value i definitely check it off board.
Yes i was talking about the component between + and -.

The worst case would actually be if the IC is dead. So cross fingers ;)

Yet the best method to debug this circuit would still be if you make a schematic with all the components. Then you could isolate the parts of the circuit where the problem has to be.
« Last Edit: November 02, 2012, 20:19:52 PM by cheerio »

stevepo

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Re: 12v Charger PCB blowing fuses
« Reply #17 on: November 02, 2012, 22:38:05 PM »
ill check those components shorly, i dont really have the skills to make a full schematic 2bh

stevepo

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Re: 12v Charger PCB blowing fuses
« Reply #18 on: November 03, 2012, 00:03:27 AM »
cheerio, its strange, D13,D14, and D16 all look like the same component close up, the same colour banding. however i have just taken D16 off the board, and its giving 600 instead of the other two that are 300, is that suspect?

stevepo

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Re: 12v Charger PCB blowing fuses
« Reply #19 on: November 03, 2012, 00:26:45 AM »
please see previous post, but also, im struggling to test this transistor, its that small that i cant read the text, and i dont have a magnifyer! i will pick one up tomorrow lol.

yea basically i dont know what the base, collector and emmiter pins are. :/ unable to read the info on the transistor. its so small.

:)

cheerio

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Re: 12v Charger PCB blowing fuses
« Reply #20 on: November 03, 2012, 00:34:27 AM »
well if the diodes are not high impedance or short they are not a big problem in most cases.
The transistor is probably a pinout like this: http://www.rectron.com/data_sheets/c1815.pdf

where are you from steve?

stevepo

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Re: 12v Charger PCB blowing fuses
« Reply #21 on: November 03, 2012, 01:42:08 AM »
uk derbyshire.

if that diagram is correct for what i have, i seem to have a reading between the collector and emitter but onl in one direction?

kam

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Re: 12v Charger PCB blowing fuses
« Reply #22 on: November 03, 2012, 07:19:22 AM »
i seem to have a reading between the collector and emitter but onl in one direction?
It is better to test a transistor live, with frequency close to the working frequency

cheerio

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Re: 12v Charger PCB blowing fuses
« Reply #23 on: November 03, 2012, 17:04:54 PM »
Well if the reading is between collector and emitter but not vice versa you probably got a pnp. but kam is right.
I am from Germany. If you want you can send me one of your dead devices and i have a look. shipping is pretty cheap between uk and ger.

stevepo

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Re: 12v Charger PCB blowing fuses
« Reply #24 on: November 05, 2012, 15:43:02 PM »
hello, i will have to get permission for this from work, what cost? other than shipping, of course which we would arrange (subject to me getting approval)

cheerio

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Re: 12v Charger PCB blowing fuses
« Reply #25 on: November 05, 2012, 16:43:33 PM »
just shipping. if you want you can donate a few bucks to this website ;)

stevepo

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Re: 12v Charger PCB blowing fuses
« Reply #26 on: November 05, 2012, 17:19:24 PM »
i think if we can get shipping at good rates we can do this :) can you message me details so i can get a shipping quote? :)