Anker 71an7105 Usb power adapter - blown fuses

[clearchris]

These are great little power supplies, except that are known for blowing fuses. The newer model has resettable fuses, so after 3 blown fuses, it was time...

Original with fuses:


After adding resettable fuses:


Not the prettiest, but considering the size of the new fuses vs the old ones, not too bad really. Each port is rated for up to 2.5a, I chose a 1.6a resettable fuse that throws at about 3a.

[ben7]

Re: Anker 71an7105 Usb power adapter - blown fuses

Nice fix!

By the way, what brand caps are in the PSU? Could we maybe get a pic of the topside of the board?

-Ben

[clearchris]

Re: Anker 71an7105 Usb power adapter - blown fuses

You got it.

Top, bottom.and close ups of caps.

[stj]

Re: Anker 71an7105 Usb power adapter - blown fuses

you need to resolder the bridge rectifier & power inlet.

[ben7]

Re: Anker 71an7105 Usb power adapter - blown fuses

Wow, that is better than I expected! They even used polymer caps!

[clearchris]

Re: Anker 71an7105 Usb power adapter - blown fuses

sti: Is that because they are a little light on solder or do you see something else?

ben7: Yeah, aside from the fuses, it's not a bad device. I was surprised to see what appears to be polymer caps as well. These came pretty cheap too, on sale for like 15$ or so. They do up to 8A across 5 ports with 2.5a max from any 2 ports at a time.

[kc8adu]

Re: Anker 71an7105 Usb power adapter - blown fuses

nice ring cracks.

[stj]

Re: Anker 71an7105 Usb power adapter - blown fuses

nice ring cracks.

exactly, the solder is cracked.

[clearchris]

Re: Anker 71an7105 Usb power adapter - blown fuses

Hmm, thanks for the heads up. I took a closer look and couldnt tell if they were cracks or some kind of residue . There were certainly rings of some sort. I removed the lead free solder and used some 63/37 instead. Nice and shiny now.

[clearchris]

Re: Anker 71an7105 Usb power adapter - blown fuses

Newer version of the power adapter.

This version seems constructed for easy replacement of fuses, the board has more room for the fuses (still not resetable) and the board has slots underneath the fuses so its a lot harder to solder it in wrong. The solder on the board is a different alloy, it requires a LOT more heat to melt.





Resetable fuses soldered in:

[ben7]

Re: Anker 71an7105 Usb power adapter - blown fuses

Nice! Now they should use a synchronous rectifier on the output :P

[airsky98]

Re: Anker 71an7105 Usb power adapter - blown fuses

These are great little power supplies, except that are known for blowing fuses. The newer model has resettable fuses, so after 3 blown fuses, it was time...

Original with fuses:


After adding resettable fuses:


Not the prettiest, but considering the size of the new fuses vs the old ones, not too bad really. Each port is rated for up to 2.5a, I chose a 1.6a resettable fuse that throws at about 3a.

what part number should i buy for the resettable fuse ? i have one lying around, got it from HK last year, too troublesome to get it fix.

[clearchris]

Re: Anker 71an7105 Usb power adapter - blown fuses

Sorry, didn't see the reply. Probably late, but here's what I bought.

Digikey:
652-MF-NSMF150-2
MFG Part No:MF-NSMF150-2
MF-NSMF150-2
Bourns Resettable Fuses - PPTC
US HTS:8533290000 ECCN:EAR99 COO:CN