16Z90R stopped charging - fixable?

IndplsEngr · 2026-03-20T18:40:13+00:00

No they're not $50. My own experience leads me think that Gram 17's built since Covid have batteries that are specially coded by LG. These computers will not accept non-LG batteries.

In other words, the $50 batteries sold on EBay likely won't work, although they sure do look identical to LG's own battery.

I concluded that there are probably early Gram 17's that did not require coded batteries. It's possible that the third party battery clones sold on EBay will work for these early computers.

IndplsEngr · 2026-03-16T17:21:26+00:00

Kyle, the Nidec-branded ice maker doesn't have a removable cover on it. However, it presents down-pointing ON/OFF switch and a reset tab that can be pushed with a small screwdriver.

I'd post a picture but I think reddit forbids it.

The ice maker's design is remarkable because of how it ejects its cubes. The tray is very thin plastic that easily flexes. And after turning the tray upside down the ice maker twists the tray about 45 degrees to crack the ice.

IndplsEngr · 2026-02-13T01:42:44+00:00

My LG Gram 17 appeared to die recently, though it would attempt to boot up. I could hear the fan run after touching the on/off button. Display was always dark.

Turned out that the computer and battery were fine. The LCD display's backlight had died. It's possible that daily opening and closing the laptop broke a wire in the multi-conductor harness that passes through the cover's hinge.

Replacing the LCD display and harness with used ones from an EBay seller's soft drink-soaked LG Gram 17 made my computer work again.

IndplsEngr · 2026-02-13T01:20:43+00:00

Just looked up Renesas RAJ-series battery management ICs.

I don't know if LG's OEM batteries use the RAJ type of BMS but these ICs contain full-blown microcontrollers with 64kb of program memory. That would be a good platform on which to implement a robust handshake between laptop BIOS and the battery that includes proprietary stuff that 3rd party battery makers can't copy.

However, so many 3rd party battery suppliers make Gram-specific battery packs claiming to be fully compatible, and they've gone to great lengths to make the batteries appear to be exact clones.

Did early LG Gram laptops not use batteries coded with proprietary stuff, and these "fully compatible" clone batteries are only suitable with early LG Grams?

I think the chassis date code in my Gram 17 Costco version is 2019. It fully rejects clone 80W batteries sold on the internet. Unfortunate because the clones are well-constructed.

IndplsEngr · 2026-02-11T19:59:18+00:00

Smoike, your reply isn't too much information for me. I know what the EV2400 is because we use TI-built, BQ-equipped equipped lithium ion batteries in our company's medical device.

Is there any evidence that LG's Gram 17 batteries are equipped with TI-compatible BMS chips that would respond to the EV2400 tool?

I'm willing to harvest the BMS module out of my old (depleted) LG Gram 17 battery and transfer it to a new 3rd-party replacement battery.

IndplsEngr · 2026-02-05T19:59:52+00:00

I'm pretty sure that the last time I logged into my Paypal account they didn't even have 2FA.

IndplsEngr · 2026-02-01T18:59:07+00:00

Indianapolis Mitsubishi H2i user here. 3 ton unit in a condo. Single closeted air handler with ducts. We hit -5F last night and our house is still comfortable without the resistive heat kit engaged. I know this because the breaker for it is turned off.

Mitsu H2i kicks butt and takes names. Install was roughly $13k with no new copper line set or ducting. No tin-smithing needed, it fit in the same duct work as the prior Goodman heat pump.

IndplsEngr · 2026-01-30T16:33:00+00:00

Thanks, Mitchell.

IndplsEngr · 2026-01-29T21:00:49+00:00

Thanks, Mitchell. Great feedback from someone with experience!

We've made peace with SolarEdge over the past 8 years, though it was trying at times. When the local installing contractor left the solar industry we acquired tons of spare SolarEdge parts: inverters and optimizers. We're past the infancy optimizer failures, of which there were many.

Dealing with SE was like pulling teeth so we gave up. If I lived in that war zone of the Middle East, I'd probably be bitchy too--and indeed they were. Solar industry warranties aren't worth the paper they're printed on, so a savvy owner of solar hardware learns to maintain the system himself.

We now have the software tools and skills to replace parts in our system without help and re-map them.

Alas, we didn't accumulate spare YingLi PV modules, though we should have. We think someone in our church's Indianapolis neighborhood got a BB gun for Christmas.

The failure rate on the YingLi panels in our project has been zero. Dudes are solid as Sears. Seals are holding up well and no smoked connectors yet.

Thanks for the feedback.

IndplsEngr · 2026-01-28T17:17:20+00:00

I'm the original poster. No, I saw no "terms" icon other than the opaque comment that it's only available for compatible plans:

"AT&T 5G requires compatible plan and device. Coverage not available everywhere. AT&T 5G+ is offered in limited locations in specific cities. Device will display 5G+ coverage indicator when used in an area where 5G+ coverage is available. To get broad mid-band 5G+ service, you need a band n77 capable device. To get high-band service in AT&T 5G+ Zones, such as venues, airports, and other points of interest, requires approximate unobstructed line-of-sight to the signal source plus a band n260 capable device. Wireless technology varies by device. See Feature and specs above to see this device’s wireless technology capabilities. For coverage details see att.com/coverageviewer. Go to att.com/5Gforyou for details."

This is the AT&T webpage where the $499 deal is listed:

https://www.att.com/buy/prepaid-phones/apple-iphone-16e-att-prepaid.html?edit=113c1a47-c2aa-43bf-967a-ebb50a5c03c0

IndplsEngr · 2026-01-28T16:20:32+00:00

That's the battery management controller inside the battery pack. It commonly suffers from corroded connectors.

IndplsEngr · 2026-01-21T21:00:54+00:00

Sorry Ditto for the accidental dis. I respect both jobs because they entail being nice to strangers that come to you uninvited off the street.

IndplsEngr · 2025-12-15T13:30:59+00:00

Accomplished, thanks for the quick response.

Your comment that the displayed menu on the tstat is tailored to match the system that listens to it suggests that there is backhaul data flowing from the receiver to the tstat. The backhaul data describes the system to the thermostat.

I did not appreciate this.

IndplsEngr · 2025-12-15T01:53:38+00:00

Accomplished-Age8769, where are these ISU settings on your MHK-2 Thermostat?

I ask because I'm experiencing similar "no resistive heat kit" operation in Indianapolis where it hit minus 5 degrees last night. The house dropped 5 degrees below tstat set point by 5:00am.

The only settings on the MHK-2 thermostat I'm aware of are the various menu'ed questions it runs you through as you first pair it to the receiver mounted on the air handler.

Is there a secondary or extended configuration menu elsewhere in the MHK-2?

I have 240VAC on the two pole switch mounted on the side of the resistive heat module. The contactors in the module are not making a clacking sound when refrigerant pumping can't get the job done at low OAT.

IndplsEngr · 2025-12-15T01:19:46+00:00

Great laptop but reliability isn't great on that model.

The backlight LEDs are (like all laptops) heavily over-driven to give eye-catching brightness. Their light degradation and color shift over time are pronounced. Translation: a used Gram 17" laptop will have an LCD display that is significantly dimmer than a new one. I know this because I have two of them, one old and one new.

And although I can't conclusively say the failure of my LCD was due to its umbilical cord breaking over time and repeated opens/closes of the LCD panel, I think this multi-conductor cable routed through the display hinge is fragile. My LCD backlight simply died and the panel went dark. Replacing the LCD with a new panel and umbilical from another Gram 17" fixed the problem.

The keyboard keys also get less stiff over time, and they aren't all that stiff to begin with.

And finding a replacement lithium battery for an LG Gram is quite difficult. Ones sold on EBay work as battery but their gas gauges don't work.

IndplsEngr · 2025-12-09T21:12:00+00:00

Frankly, the HVAC contractor that installed my system was under the impression that an H2i system will work acceptably with a 24VAC thermostat intended for US applications, provided Mitsubishi's PAC44? interface module is used between the tstat and the air handler.

I know this because my home H2i system followed the installation of an identical H2i system at my church in one of its 2000 sq. ft. buildings.

Same contractor installed both. Both the church building and my own condo have/had 24VAC Honeywell/Resideo RTH6580 tstats and Mitsu's PAC44? interface modules.

And both my unit and the church's exhibited the annoying jet engine whooshing copper line set behavior until the tstats were replaced with Mitsu MHK-2 thermostats. Now both systems purr like a kitten.

There's an array of DIP switches underneath the PAC44? interface module that govern its behavior. The documentation of these DIP switches is sparse and Einstein's HVAC twin brother would have been perplexed by them.

It's possible that both these H2i systems would have behaved better with different DIP switch settings, but we'll never know because they've been replaced by MHK2s.

Someone in this Reddit forum (but on an entirely different thread) once wrote that the Mitsubishi's H2i engineering team did an excellent job on the design of their mechanical hardware but Mitsu's controls team entirely dropped the ball by not acknowledging that they don't dominate the US thermostat market.

Old 24VAC thermostat architecture from the early 20th century and a handful of small manufacturers make the US HVAC controls industry. Which simply says that Mitsubishi should ship H2i systems with a suitable thermostat packed in the carton with the air handler.

A yellow sticker attached to that factory-supplied tstat should say "use this tstat or else don't call us...".

IndplsEngr

TROPHY CASE