Does your meter display 1 if it’s out of range on the scale or something?
Only ask as 1 ohm can’t be possibe here with BQ, diode and inductor removed… you should be measuring OL (over limit/open cicuit) afaik.
The sizes can be determined by measuring the existing caps with a pair of calipers, the voltage rating can be determined by looking at the Max voltage present on this rail/line in the datasheet, as long as the replacement cap voltage is greater than that of what’s listed in the datasheet it is suitable.
In this case the cap with the missing endcap is on the SYS rail and the datasheet specifies a max voltage of 4.35V, as such, a capacitor that has a voltage greater than 4.35V is suitable.
Definately for the time being remove the capacitor with the missing end cap to take this out of the equation.
Well if that’s the case, you might well have resolved your fault
Bit strange it shows 1 though, how do you tell the difference between OL and 1 ohm otherwise
So you might want to reinstall the BQ IC, afaict power and charging functionality should still work without this diode present.
As for the backlight driver IC, provided it is not damaged or suffering an internal fault you could use a stencil and solder paste or alternatively you could just buy a new chip which comes preballed.
but you should be able to monitor current draw without this backlight IC installed to confirm you have resolved the other fault.
Just add, after you’ve reinstalled the BQ IC, before plugging in the battery or charger, measure the resistance to ground on the Inductor again and ensure there is no short present (just in case the BQ IC had also gone bad)
It’s a no go. I tried my best to use the heat gun and solder the BQ chip back into place, it took me two attempts and I tested the caps around it, and none short to ground. After that, I resoldered the inductor to make sure I could power this thing back on and test the board with an ampmeter. Inductor is soldered but now I get 0A. I guess the struggle continues -_-’
That missing resistor of yours seems to lead to the REGEN pin of BQ, the resistor goes to TS1/2 afaict
From the datasheet, key part in bold
Temperature qualification voltage input #1. Connect a negative temperature coefficient thermistor.Program temperature window with a resistor divider from REGN to TS1 to GND.Charge suspends when either TS pin is out of range.Recommend 103AT-2 thermistor.TS1 and TS2 pins have to be shorted together in bq24193
Yea I thought so. Looks like another roadblock.
Isn’t there a way of testing just the BQ chip to make sure it’s sitting on its spot and I should worry about it no more? For example, if I test its satellite-components and they don’t short, could that serve as an indicator? What would you do to make sure all the legs are soldered?
Thank you for that. I will let you know when I get a hold of this component.
Which we’re going to assume is OL for the time being which is better than before. It should measure aprox 7K from memory relative to ground.
Would reccommend picking up a UT61E meter as it is a good budget meter and will rule out a lot of the cinfusion with your current meter.
Yeah you can run round with your meter in diode/resistance mode and compare the readings to another board which will give you a pretty good idea. Calvin has made a diode mode map of this area I’ll see if I can find it.
Well, it can give a rough idea that you haven’t bridged one of the pins/pads of the BQ to ground, but other than that, it doesn’t tell you if you’ve bridged two other pins not otherwise ground.
It seems my meter showed 1. as in “You should use the correct RANGE thsi time”. And so I did. So I moved up from 20k to 2M Ohms and the left side of the Inductor reads .770 and the right side reads .782. I mean on the left side, value goes up - same with the right end of the inductor but after some time, each reading won’t go past those values.
That’s right, my meter doesn’t adjust the range automagically, I have to do it manually.
Question: Should each end of the inductor have the results I mentioned or just one? If the latter, it’d probably indicate there’s a solder bridge.
I still think you meter is acting strange (would highly reccommend picking up an auto raging metere such as UT61E)
So either the BQ IC isn’t soldered properly, or, far more likely your meter is giving you a duff reading and it’s actually 7.7K (which is about the correct reading at this location)
Either way, this represents an open rather than a short which is fine.
Go round the pads around the BQ IC, put your meter in diode mode, put your red probe on ground and if any of the readings differ significantly from Calvin’s diagram lemme know. If all looks good though, then BQ is likely soldered fine.
I agree with the latter. Comparing my results against Calvin’s reference, there isn’t much of a difference. I also spotted two grounds around the BQ chip and those values are approximately the same, for more or less, within the margin of error.
I don’t want to connect the Switch Lite’s USB-C port to the meter, which is connected to a USB3 port to see how many Amps I get. I guess without that diode you pointed out to be removed previously, chances are some current can take the wrong way upon powering on the board and hit a source, am I right?
So what’s the next move?
Each end of the inductor gives pretty much THE SAME VALUE, is that right? Or was it supposed to be just one?
I’m going to stock those components placed around BQ IC. @SheriffBuck these are the ones I’d like to replace:
Some caps look burned and I accidentally blew away both components you mentioned (0201 10uF cap - by the way, should I go for 5V or 10V?) and the 0201 10k resistor.
Even worse is the diode which seems to be the culprit or the reason for the short; It’s between the inductor and the capacitor and I found no way to ID it. Because of that diode, I don’t feel like powering on this board anymore in order to check how many Amps I get.
I couldn’t agree more. The Switch LITE design looks more like a project that an intern decided to ditch because they thought it was too risky to materialize, for it would be such an easy-to-break design. A cable responsible for the transportation of at least 17V to feed the LED panel is folded twice, glued along the battery case and travels across to the daughterboard. And people think the regular Switch is hard. Try the Switch Lite, see how HARDER this gets.
I can’t go on with the lack of information on those missing chips.
I’ve purchased the board from my customer. (Yes, that’s the one I’ve messed with).
I think people tend to find more issues with the regular Switch than the Lite. Also, @Severence mentioned I might need a new meter, but I’m going to purchase another Switch Lite and take measurements from it, then compare with this faulty board. If the readings are off, then I’ll go for another meter. Yes, I know this sounds like the hardest and the toughest way to handle this situation, but it’s the only one I might actually LEARN from it. @SheriffBuck If you get any info from those components surrounding the BQ 24193 chip I mentioned on my previous post, PLEASE do let me know .
Once I get a new Switch Lite and compare those values, and if I find anything worth mentioning, I’ll post it here. But because of that UNKNOWN diode between the inductor and the BQ-surrounding cap, I think it’s very risky to power on this Switch Lite again, so this is going to be a no-fix for the time being.
Can’t say for sure what the purpose of that diode is without the board in front of me and/or the diode, so whether it’s for reverse voltage protect or for clamping I have no idea… what I can say is Nintendo chose not to populate it on the regular switch board, why they chose to populate it on Lites, I don’t know, maybe they were addressing a common fault on the regular switch boards or perhaps it’s due to the slight design differences of the Lites…
Your call but I don’t see why you can’t test without the diode present. I would be more concerned about your missing resistor as I don’t think you’ll get charge current without it, but you can try also.
Well, aren’t diodes supposed to keep the current from coming back to the source and damage a chip? I can’t know how safe it is to proceed without an opinion from someone who has tried it before on their Switch Lite board. Sure I can move on and try soldering down a new resistor but if you know someone who’s tried powering on their Switch Lite without that diode and they tell you it’s safe to do it, please let me know and I will proceed.
Until then, I’m on the lookout for a replacement of the component or a Switch Lite (main) board replacement on Ebay to extract the bloody diode from.
Hi,
What software did you use to make this boardview? could you share the file please? I am investigating on a similar issue and I’d like to use a tool to make a boardview and fill it with the data I have gathered so far.
It’s not my work, these are created by the user @Calvin
afict it looks like a vector to me.
The trouble with creating a boardview is that afaik you’d need to create a schematic prior in all the tools I’ve looked at such as Kicad, fusion/eagle etc… did make a start but it’s too much work and fusion was a bit broken & buggy at the time
Thank you for the quick reply. I wish there was a tool where I could just create a boardview without schematic. I should probably take a look at some reverse engineering tool for pcb.
I take this opportunity to ask another question. After several investigation on a switch lite and comparison with a fully working one, I ended up finding a shorted IC close to ALC5639. The only thing I can read on the component is “S2”.
According to the diode symbol next to it, I suppose it is a 4-pin diode but I have not managed to find out more about its identity. How can I find out more about this IC? Does anyone know what it is?
