5V boost converter smoked on first use

[grumpazoid]

I have purchased some of the recommended 5V boost boards at https://www.ebay.com/itm/DC-DC-Boost-Converter-Module-Step-Up-Module-1-5V-to-5V-500mA-for-phone-MP4-MP3/381185956688.

As soon as I have applied approx 4VDC at the input (no load) the board my PSU has hit the current limit. No wanting to give up so easily I then tried an 18650, which produces some nice smoke.

faulty board or operator error?

[mfalkvidd]

@grumpazoid I'd say operator error if you connected the power supply incorrectly, faulty board if you connected the power supply correctly ;-)

[alowhum]

It's difficult to say with so little information.

Do you have a picture of the board?

How did you wire things up exactly? Are you sure you didn't reverse polarity? Perhaps you're sot supposed to run these without a load?

[grumpazoid]

I was wondering about the no load.

I've just carried our some further investigation . It looks like C3 that is connected between ground and 5V O/P has been shorted out with solder. I guess this would exceed the 500mA specified ;).

[grumpazoid]

https://i.imgur.com/w38Goat.jpg

[bjacobse]

This post is deleted!

[bjacobse]

This seems that E50D might be same as CE8301, but somehow they use a smaller cap, maybe to save money, try to replace C3 with a 100uf 16V electrolyte capacitor

https://www.sunrom.com/p/5v-dc-dc-boost-step-up

[grumpazoid]

@bjacobse Thanks. In the end i removed the solder that was shorting out the capacitor and it now outputs 5V. Not sure how safe it is after the overheat
As an experiment I cut the track to take the LED out the circuit. This reduced the current from 2mA down to a few uA.