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?

On Tuesday, December 20, 2016 at 11:11:50 AM UTC-5, N_Cook wrote:
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?

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

On 20/12/2016 17:15, wrote:
On Tuesday, December 20, 2016 at 11:11:50 AM UTC-5, N_Cook wrote:
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?

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


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

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

On 21/12/2016 18:57, wrote:

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



Cracked ferrite of the inverter transformer or AC output RFI filer
torroid with live and neutral turns both around it?