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Nikkai N64AU 12V inverter to mains

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N_Cook

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Dec 20, 2016, 11:11:50 AM12/20/16
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Dropped on hard floor and now just 1/2 second LED illumination.
No sophisticated chippery inside, an LM324 and 2x TL494, no SMD unless
under something.
No obviously failed solder joints of big lumps or elsewhere , no cracked
pcb.
4 IRF740 and 4x RFPN06 and a 7812 complete the main active stuff, what
would be most likely mechanical failure inside? DIP IC, transistor,
diode, other?

pf...@aol.com

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Dec 20, 2016, 12:15:26 PM12/20/16
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Look wherever something heavy is attached to something light, and at some angle other than aligned to the drop force. Anywhere there is heat at such a connection, irrespective of the angle-of-force.

This will be something that bright light and a magnifying glass will reveal along with the usual 'wiggle-it-a-little". And, as you are not getting _any_ symptoms, I suspect more towards the input side of things.

Peter Wieck
Melrose Park, PA

N_Cook

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Dec 20, 2016, 1:26:16 PM12/20/16
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error in title, renamed model.
First one of these things I've looked at, no SMD but lots of on-end "6
transitor radio" fashion minor comps.
First thing to try is cleaning and refitting the 2 TL494 as they're in
sprung sockets for some odd reason

mako...@yahoo.com

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Dec 21, 2016, 1:57:20 PM12/21/16
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> >> Dropped on hard floor and now just 1/2 second LED illumination.

cracked ferrite core causing over current fault?

those things usually both sides of the output outlet differential relative to chassis ground and they have a kind of ground fault sensor to shut
the inverter off if there is any significant flow to the ground pin.

m


N_Cook

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Dec 21, 2016, 3:16:17 PM12/21/16
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Cracked ferrite of the inverter transformer or AC output RFI filer
torroid with live and neutral turns both around it?
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