keyboard catastrophic failure - Page 1
Forum section: electronics / general

author: confusion
author_rank: Contributor
timestamp: October 08, 2025, 10:13:57 pm
content: I had a royal kludge RK61 wireless keyboard recently set itself on fire. I own a few more of kludge branded keyboards and now I'm really concerned about leaving them lying around the houseI suspect when charging the product has no protections and is completely unregulatedI have a benchtop power supply, multimeter, tools and time to tear the thing down.I was also considering sending it in to Dave but I worry that it would just get lost with the hundreds of items that he receives weekly. Im in Sydney so it's not much hassle.Thoughts?Some photos I uploaded yesterday to Reddit:https://www.reddit.com/r/MechanicalKeyboards/comments/1o14ado/royal_kludge_safety_psa/PS: does this form not have drafts? I just hit the back button and everything got deleted

author: Someone
author_rank: Super Contributor
timestamp: October 08, 2025, 10:28:36 pm
content: Most people in electronics wouldn't call that a fire, the self extinguishing materials all did their job and didn't catch on fire.A single burnt out chip? Not some massive disaster.That BYK901 is a dedicated keyboard controller chip, even available for replacement (programming required?). Do you know the keyboard negotiates USB-C PD ? I'd guess its passive.

author: confusion
author_rank: Contributor
timestamp: October 08, 2025, 10:36:31 pm
content: I agree that the flame retardant outer case stopped the fire from progressing.Honestly, would you just leave the other keyboards around your house and be comfortable with that?I am curious as to WHY it started in the first place.I agree that the keyboard would probably not have PD. I'm not sure how that manifests itself. I thought if no handshake happens, you just get 5v at 2A or something 'safe'

author: thm_w
author_rank: Super Contributor
timestamp: October 09, 2025, 12:08:07 am
content: The main MCU burning up is odd. Someone linked this thread:https://www.eevblog.com/forum/microcontrollers/ic-(hfd48kp500)-on-rk61-keyboard-datasheet/It looks like there is a buck regulator off to the left (L5, DA3, etc.), you could check if that IC is shorted, which would have supplied 5V to the mcu. Otherwise could be a noise/switching voltage coming from the USB supply, and this kb not having much filtering.What brand is the GAN charger?Quote

author: langwadt
author_rank: Super Contributor
timestamp: October 09, 2025, 12:12:13 am
content: it wasn't catastrophic, there was a big failure but it extinguished itself containing the problem as it is supposed to

author: amyk
author_rank: Super Contributor
timestamp: October 09, 2025, 02:38:42 am
content: It's the first time I've seen that happen to a keyboard.What was it plugged into when it burnt? I personally think USB-C and its insane complexity is a bit scary, especially with adapters that can deliver more than 5V --- and that will certainly cause such damage, with the keyboard being completely innocent.On the bright side, the single lipo cell has its own protection circuit.

author: confusion
author_rank: Contributor
timestamp: October 09, 2025, 04:39:10 am
content: Quote from: langwadt on October 09, 2025, 12:12:13 amSemantically, maybe. I don't know. I thought a short that turned into an open flame would classify as catastrophic.Practically, would you just leave the other keyboards around your house and be comfortable with that?

author: confusion
author_rank: Contributor
timestamp: October 09, 2025, 04:43:45 am
content: Quote from: thm_w on October 09, 2025, 12:08:07 am

author: confusion
author_rank: Contributor
timestamp: October 09, 2025, 04:44:39 am
content: Pretty sure it was plugged in but can't be certain

author: confusion
author_rank: Contributor
timestamp: October 09, 2025, 04:51:00 am
content: Quote from another thread elsewhere:The burned part looks like around pin 44-48, the power supply section. Were you plugged into the usb? I'm wondering if the keyboard somehow reported the usb PD mode wrong and the computer suppled PD voltage of 10-15v?

author: Haenk
author_rank: Super Contributor
timestamp: October 09, 2025, 06:33:27 am
content: Quote from: amyk on October 09, 2025, 02:38:42 amYep. Never saw a keyboard catching fire. Dropping some unnecessary key, yes. Getting rid of its cabling, yes. Storing a larger pool of Coca Cola, coffee or tea, yes, absolutely. Or even breeding some wool mice, yes.

author: Whales
author_rank: Super Contributor
timestamp: October 09, 2025, 07:04:22 am
content: +1 to suspecting the USB power supply you had this plugged into. A detonation that big on a logic IC isn't something I would expect from 5V.Quote from: confusion on October 08, 2025, 10:13:57 pmNo. Most forum software is designed assuming it is the responsibility of the browser to keep the contents of a <textarea> around when you hit back/forwards. As you're aware this fails arbitrarily and when you least suspect itWorkaround I use:https://addons.mozilla.org/en-US/firefox/addon/form-history-control/

author: thm_w
author_rank: Super Contributor
timestamp: October 09, 2025, 08:36:58 pm
content: Quote from: confusion on October 09, 2025, 04:43:45 amYes without handshake it would just output 5V. Only the cheapest of the cheap garbage don't do that.Its still possible during some transition stage it output a high voltage spike momentarily, as they usually use an intermediate voltage of 20V or 24V. Without a scope and playing around plugging/unplugging stuff you won't really know though.I don't see any other failures mentioned in the ali reviews.

author: langwadt
author_rank: Super Contributor
timestamp: October 09, 2025, 09:51:59 pm
content: Quote from: thm_w on October 09, 2025, 08:36:58 pmusb-c shouldn't output power unless something is plugged in so there should be no way to get more than 5V unless you request itunless using something dumb like this:https://pcper.com/wp-content/uploads/2025/04/usb-c-splitter.pngif one of the devices request 20V they are probably all going to get 20V ....

author: thm_w
author_rank: Super Contributor
timestamp: October 09, 2025, 09:56:20 pm
content: Actually quick google search shows this has happend before:https://www.reddit.com/r/UsbCHardware/comments/1hmacvp/stay_away_from_asometech_chargers_fried_3_of_my/QuoteDo not use no-name USB chargers, its not worth it.Royal Kludge as shitty as they are, I don't think are to blame here.

author: Someone
author_rank: Super Contributor
timestamp: October 10, 2025, 12:01:41 am
content: Quote from: langwadt on October 09, 2025, 09:51:59 pmEqually there have been occasional reports of USB-C sources not discharging their outputs down to vSafe5V quickly enough after disconnect of a negotiated device. So I've been putting 20V withstand on any USB-C input despite the standards not requiring it.

author: confusion
author_rank: Contributor
timestamp: October 10, 2025, 12:17:59 am
content: That's really scary. I have a carbon copy functioning RK61 so a teardown/re-creation would be possible.You guys probably know better than me but might this be something Dave would be interested in looking at? And if so, is there an email address somewhere?Just seems like something that's going to be a real issue going forward with the proliferation of USB C...

author: Kean
author_rank: Unknown
timestamp: October 10, 2025, 12:23:59 am
content: Quote from: confusion on October 10, 2025, 12:17:59 amhttps://www.eevblog.com/about/contact/The ASOMETECH charger is what needs to be tested further. This might require a USB C trigger, some automation, and mask testing on a scope if it is only an occasional issue.No need to destroy another keyboard, even if it is a RK...

author: thm_w
author_rank: Super Contributor
timestamp: October 10, 2025, 02:14:05 am
content: Quote from: Someone on October 10, 2025, 12:01:41 amIt looks like there is something in the spec about a 400R discharge resistor, but I could easily see that being missed on cheap chargers, or violated due to variations in output capacitance, etc. If you've got the budget, handling it seems like a good idea.https://www.usb.org/sites/default/files/documents/usb-port_controller_specification_rev2.0_v1.0_0.pdfQuote

author: Someone
author_rank: Super Contributor
timestamp: October 10, 2025, 03:46:22 am
content: Quote from: thm_w on October 10, 2025, 02:14:05 amThats on the sink end! Sources have similar requirements too.

author: EEVblog
author_rank: Unknown
timestamp: October 10, 2025, 11:24:50 pm
content: Quote from: confusion on October 08, 2025, 10:36:31 pmYou do.That doesn't mean there aren't badly designed USB-C sources though. Or badly designed USB-C devices for that matter.

author: EEVblog
author_rank: Unknown
timestamp: October 10, 2025, 11:27:12 pm
content: Quote from: confusion on October 10, 2025, 12:17:59 amUSB-C is already prolific and the dominant standard, and has been for years. If there was an epidemic of issues we'd already know about it. So I'd put this down to just a single dodgy product.

author: squadchannel
author_rank: Frequent Contributor
timestamp: October 11, 2025, 12:15:04 am
content: Some USB-C adapters lack the concept of negotiation and always supply 9/15/20V.But if they had even a fuse, it might have been preventable.

author: amyk
author_rank: Super Contributor
timestamp: October 11, 2025, 02:53:07 am
content: I maintain my position that software-controlled voltage on a PSU is a stupid idea. Too much complexity and opportunity for (catastrophic) failure. USB should've stayed at 5V.A fuse is unlikely to help; if the PSU can supply 5A at 20V it will happily continue doing that into a 4 ohm load, even if that load is a former chip that has burned into a resistor.

author: EEVblog
author_rank: Unknown
timestamp: October 11, 2025, 03:03:50 am
content: Quote from: amyk on October 11, 2025, 02:53:07 amIn that case it's an end product robustness design issue. Zener and a fuse.No different to any product with a user DC input, be it USB or DC jack or something else. If you don't design it to prevent overvoltage input then ya'takes'ya'chances.

author: langwadt
author_rank: Super Contributor
timestamp: October 11, 2025, 10:51:52 am
content: Quote from: EEVblog on October 11, 2025, 03:03:50 amI'm sure quite few things have died when picking a random wall wart in drawer and it happens to be a 48V for POE

author: Someone
author_rank: Super Contributor
timestamp: October 11, 2025, 11:15:42 am
content: Quote from: langwadt on October 11, 2025, 10:51:52 am54V 56V, theoretically 57V for PoE

author: langwadt
author_rank: Super Contributor
timestamp: October 11, 2025, 11:35:52 am
content: Quote from: Someone on October 11, 2025, 11:15:42 ammost switches and such I've seen use a 48V supply