I’ve been reading the mail on this topic. I purchased a KIO3B from the last run thinking it would be a good backup when the KIO3A failed. I prefer using RS232 for my K3 and K2 rig control using a PCI card in the shack computer. Digital modes are of slight interest using a sound card in the shack computer.
Looks like I’ll keep the KIO3B in the box and may never need it. Like Bob, and others I suspect, at my stage of life 82 years young, my K3 s/n 6011, will be probably be my last HF rig. It’s been a great run with the gear (K1, K2, K3) from Watsonville. Thanks for the memories! Clark / WU4B Sent from Gmail Mobile On Sun, May 11, 2025 at 11:57 AM Joe Subich, W4TV <[email protected]> wrote: > > > > A caveat, I have not tested the 'repaired' KIO3B board, that's still > > on my to-do list. Hopefully D1/R27 did their jobs and sacrificed > > themselves for the good of the board. > D1 should do its job. However, R27 is between the USB cable shield > and circuit common ("ground") which indicates your original failure > was a reverse voltage condition (shield became positive relative to > Vbus). > > This does point out the real problem with Elecraft and repair of the > KIO3B ... Elecraft have a ~$400 minimum service fee (@ $100/hr). A > "simple" repair/replacement of D1/R27 would be more expensive at the > minimum service fee than the replacement KIO3b (when they were > available). Now, the time to troubleshoot a bad KIO3b might consume > the entire 4 hour minimum if the damage was extensive - although > given my experience with USB products the mast majority of the > problems are likely to be D1 with or without R27 (particularly since > Elecraft seem to have gone to great lengths to isolate the "USB Core" > from "raw" Vusb. > > 73, > > ... Joe, W4TV > > > On 2025-05-11 10:40 AM, John Canfield wrote: > > My KIO3B suffered the typical USB failure a few years ago but > > fortunately Elecraft was still repairing the K3s then. They replaced the > > KIO3B board and returned the old one. I kept the old board for a long > > time but got interested in trying to repair the failed board (USB > > defective but RS-232 was fine.) > > > > My USB failure (or I suppose the most obvious one) is on the Digital I/O > > Module (E850646) board. Specifically D1 and R27. D1 is an STMicro > > USBLC6-2P6, an ESD protection device. Mouser part # 511-USBLC6-2P6. R27 > > is just a zero ohm resistor, I suppose it's used as a fuse. If it's not > > obvious these are surface mount devices so it does take a bit of > > patience and of course the right tools to replace them (or any surface > > mount device for that matter.) > > > > An intact D1 will have an all black case/housing/shell (whatever you > > want to call it), the defective one on my board literally had the top > > part of the case/shell blown off. R27 is in series with the shield lead > > from the USB connector to ground, my R27 was open. D1 and R27 are > > located very near the USB connector so they are fairly easy to find. D1 > > was inexpensive, I forgot how much but I bought five of them just in > case. > > > > A caveat, I have not tested the 'repaired' KIO3B board, that's still on > > my to-do list. Hopefully D1/R27 did their jobs and sacrificed themselves > > for the good of the board. > > > > 73 John W5TWO (ex WB5THT) > > In the Texas Hill Country > > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
