Dead Switch wont start, help with diagnostics

Reinstalled BQ and changed the ic from above.

If i Charge the switch with connected battery via 3Amps Phone charger i get 5.1 volts with 0.2Amps.

Cant Connect original charger and measure Amps due to the normal usb Connection my diagnostic tool has.

Any idea about the Ratings?

Edit: my working switch charges with 5.1 volts @ 0.4 amps

Could be a few things (I’ll assume your BQ IC and re-install is good (?) ) - could be battery issue relating to the middle wire on the contact (I think it’s termed “therm”)

Could be Fuel gauge related issue

Could be USB related issues (you’d wanna do visual inspection and if good, then do continuity check from breakout board to/from destinations)

Could be M92 IC (or M92 IC install) issues. Could also be related circuitry such as the diode, filter, fuse etc

Should actually be higher than this (if the battery is semi-depleted) anywhere from 0.6 to 2A (I think, somehwere in that region)

I don’t get this… did you confirm that it wasn’t actually functioning?

Is it functioning now?

Does the console actually even power on currently?

nope. Still not powering on. I had some other problems which came across while trying to reflow bq and max chip several times. Some resistors went missing while trying to fill the pins with solder. I could restore them, but after several times of reflowing the m92, i burned some of the pads.

While the m92 was still in place i could identify shorted caps (maybe m92 went bad because of too much heat?)
Shorts disappeared after removing it. Here is the picture of the restored pads. Install a new m92 again and well see if it helps or not.

problem nr. 1 i have is that im not patient enough :smiley: next time i need to wait till all the tools like the voltage meter arrive before i start to solder and make diagnostics.
All the lightbulbs like you said that came across are now kinda destroyed.

btw. if i plug the cable in i can measure 0.xx at vsys and vbat. does this have something to do with the max chip or should i get 5.xx or something like that here anyway even with bad / no max chip?

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Bit hard to tell whats missing from that image due to the darkness and your solder mask… at least a few caps missing afaict.

More likely you pulled the pads off when attempting to pull the IC off the board too soon, and/or knocking them off with your iron. Be a bit unlikely heat alone would cause the pads to be lost. (first case can cause layer delamination which can cause more serious issues)

:thinking: don’t think so… either a fake IC or more likely, you bridged one or more of the pins/pads

:rofl: (I genuinly laughed)

Trouble now is the water is muddied, can’t troubleshoot the original fault because we are now troubleshooting BQ IC potential issues, and we can’t troubleshoot that because we now have M92 issues at play too, and we can’t troubleshoot that because we now don’t know if you’ve caused issues at the ENXX IC, and so on, and so forth :upside_down_face:

Probably imply BQ install issues.

Not really, this is because you’ve seen some moron youtuber say this… the only thing it has in common is SYS (but almost everything has SYS in common as it’s the most used VIN on the board) … no more lightbulb moments ya hear :stuck_out_tongue:

In all honesty this board is probably best suited as a donor board at this point, but if you wanna try, then best suggestion at this point is to try and get BQ and M92 back on the board properly without causing further damage, really make sure of this prior to anything else, then once you’ve verified all that, go and check the ENXX IC measurments we talked about earlier and make sure it’s outputing and if no if it’s being told to do so at it’s enable etc etc :+1:

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