MNT Reform stopped charging

MNT Reform
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Today, I went to charge my MNT Reform and… nope! I am having a bad hardware karma week, it feels like.

It’s at ~17% charge, and the batteries are just fine as near as I can tell, but plugging in external power doesn’t light up the charging LEDs as it normally would. Additionally, the OLED looks like I might have a bit of burn-in, as whenever it’s lit, I can see the ghost of the battery output interfering with what it’s displaying. That’s probably my own fault and unrelated to whatever is going on, but it does seem new.

I did not smell anything when this happened, and I don’t see anything obviously damaged on the board. The barrel jack seems firmly attached.

I have an external battery charger that can take 18650 LiFePo cells, so if this ends up being a firmware thing i should be able to flash it with fresh cells, although I know that’s suboptimal.

Any ideas?

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Sound bad, but maybe there is way here. Does the laptop function/light without batteries and only external power connected? I’m assuming, it should work without any batteries installed.

Also does the external power function well, need to check that. But since you mention barrel jack, you’re using external PSU. And those normally use attachable power cable, which may dislodge over time, make sure it’s well seated.

Edit: Here is short discussion about running Classic Reform without batteries. Is it okay to remove the LiFePo4 18650 cells?

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This hadn’t even occurred to me! It’s running fine on the batteries, just not charging them – it seemed to me like the wired power circuit wasn’t working at all.

I still haven’t tried powering it without the batteries and the barrel jack (motherboard v2.5) plugged in, but I suspect it won’t work – according to my multimeter I don’t have continuity or voltage across the component labelled F1, which I’m guessing is a fuse…

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What are you using to power the thing, the stock Mean Well brick? I don’t think it’s capable of supplying enough current to blow that fuse unless it malfunctions.

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I’ve been experimenting with powering it with a lot of different things, and that was clearly my downfall. I was using a 12v dc output from a solar power station that I’d used before – and clearly it tripped something (it can push up to 8a). I’ve replaced the fuse as of this morning, and it’s behaving mostly normally now – it seems to have some trouble charging at low states of charge if I’m also using the machine at the same time, resetting more than I would expect, even on the default power supply, where the blue light is blinking off and the LPC display showing input going from negative/charging to 0 to positive/draining and back.

I’m having the best luck with a USB C PD to 20v, 5a 5521 barrel jack cable.

So it’s possible I have some other downstream damage in the power system, but it’s working well enough for my purposes at this point, and I have the v3.0 motherboard ordered from the shop, so… lesson learned on this, and I at least have some spare fuses now.

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That sounds like your Reform is pulling too much current and the power supply is cutting off to protect itself and the connected equipment.

Mine used to do that with USB PD chargers pretty regularly. Changing some of the resistors to limit the charging current helped, but it’s still a bit of a power hog.

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That makes a lot of sense! So far, despite that behavior, it’s working fine – and it may be it was always doing this, and I just didn’t notice.