Calling all PC experts - I have a weird keyboard issue - Page 1
Forum section: electronics / general

author: xrunner
author_rank: Super Contributor
timestamp: September 10, 2013, 12:21:46 am
content: I'm stumped. Really stumped.I ordered a new small footprint keyboard from Hong Kong over Ebay last week. I'm going to use it for my ham radio hobby desk PC. It arrived today and it looked nice. I plugged it into a front USB port on the PC and tested it. It worked just fine. It's the right size and the keys have a nice feel. I thought all would end well. It didn't.Here's the item -http://www.ebay.com/itm/261053848553?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648So I then unplugged it and plugged it into a USB port on the back of the PC - one that is directly connected to the MoBo. It didn't work, at least not reliably. On bootup I couldn't get into the bios by hitting Del because it reported no KB found. Sometimes even after Windoze finished booting I could not enter my password. I tried all four rear ports and it acts the same way. It doesn't work correctly.When I use one of the two front ports, which are connected by wires to other MoBo USB port pins, it works OK.I do not understand this. There is nothing in the bios that differentiates the rear ports from the front ports. Also, the other devices using the rear USB ports, such as a SDR dongle, do not exhibit any issues whatsoever. I have never encountered an issue like this before.Any ideas?

author: mmagin
author_rank: Frequent Contributor
timestamp: September 10, 2013, 12:38:20 am
content: Poor mechanical tolerances in the plug?

author: marshallh
author_rank: Unknown
timestamp: September 10, 2013, 12:45:10 am
content: Could be power filtering. I wouldn't be surprised if they only populated 1 or 2 out of the 10-20 needed bypass caps in the keyboard pcb.Might want to open it up and add some.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: September 10, 2013, 01:08:41 am
content: hi,what sort of case do you have ? ,if its an older one it could have usb 1.1 ports even though you connect them to a usb 2 header.Also check your bios for legacy usb support and usb keyboard support.

author: xrunner
author_rank: Super Contributor
timestamp: September 10, 2013, 01:15:59 am
content: Quote from: mmagin on September 10, 2013, 12:38:20 amPossibly ...The front ports might grip the KB connector better. Yet I can't recall this ever being an issue in many years of PC use/hobby.Quote from: marshallh on September 10, 2013, 12:45:10 amAgain - possibly. Like you said I'd have to open it up.Quote from: fluxcapacitor on September 10, 2013, 01:08:41 amIt is a bit older.QuoteI doubt it has 1.1 ports. I'll check the MoBo manual, I suppose it's about time. But it's a KB - I wouldn't think speed would have an issue at all. I suppose I can just leave the thing plugged into the front port, but I hate not understanding these types of problems.

author: ablacon64
author_rank: Frequent Contributor
timestamp: September 10, 2013, 01:21:48 am
content: Some days ago I faced the same problem and bios setup had 3 configuration options:1 - Optimized defaults for SATA (AHCI)2 - Optimized defaults for IDE3 - Bios defaultsDid not know what the third option meant but it was the only that worked. The board was an asrock with soldered Atom cpu. I stopped trying to understand the problem.Post motherboard brand and model.

author: dfmischler
author_rank: Frequent Contributor
timestamp: September 10, 2013, 01:27:01 am
content: Is there an option on the motherboard for providing USB power? I have a couple of boards that have more than one jumper for USB power or not on different groups of ports (e.g. jumper USBPW1-4 controls power on ports 1-4 on the back panel on an ASUS M5A78L-M LX).

author: AlfBaz
author_rank: Super Contributor
timestamp: September 10, 2013, 01:42:19 am
content: LOL... this thread reminds me of an episode of futurama "wiggle the cord, ctrl alt delete, turn it on and off..."and to that end, try plugging the dongle into the same rear port but this time on the end of a cable and place it closer to the keyboard (I'm looking at your "at least not reliably" remark), transceiver might be poor quality

author: xrunner
author_rank: Super Contributor
timestamp: September 10, 2013, 01:52:14 am
content: Thanks for all the additional replies. I'll keep at it. I mean it's a f*cking KB right? What's with it not just - working out of the box?

author: AlfBaz
author_rank: Super Contributor
timestamp: September 10, 2013, 01:56:59 am
content: Quote from: xrunner on September 10, 2013, 01:52:14 amHave you tried using it in the box?

author: xrunner
author_rank: Super Contributor
timestamp: September 10, 2013, 02:01:52 am
content: Quote from: AlfBaz on September 10, 2013, 01:56:59 amGood one.

author: pickle9000
author_rank: Super Contributor
timestamp: September 10, 2013, 02:20:30 am
content: Make sure your connectors are clean. A short 6 inch usb extension can sometimes help. Pop the back off the keyboard and see if they used tape instead of solder (check for unpopulated caps). If you happen to have a usb to ps2 adapter and your comp accepts ps2 then try that.

author: westfw
author_rank: Super Contributor
timestamp: September 10, 2013, 02:40:15 am
content: QuoteAre you kidding? I keyboard is usually a single-chip 8051-class (slow) wonder. Why would it possibly need 10 to 20 bypass caps.Are you sure the port you're plugging it into is good? I've seen individual USB ports go bad in both electrical and mechanical ways. (also: dirty or corroded contacts?)

author: Psi
author_rank: Super Contributor
timestamp: September 10, 2013, 02:52:07 am
content: You need to enable "USB keyboard support"/"USB legacy support" in the bios before a usb keyboard will work for chancing bios stuff.Also, when you move a device between different USB ports it can take windows a while to figure out what you've done.If you change the USB port then boot up windows (and the device doesn't work) it usually just needs to be unplugged for a few sec and then put back in.Sometimes it can take a while to detect because windows is busy loading and doesn't have time for new hardware.Once its been detected on that port it should work fine in the future for entering login details.Also i've seen motherboards with dead usb ports, so might pay to check with a usb flash drive or something just so you know the port is good.

author: edavid
author_rank: Super Contributor
timestamp: September 10, 2013, 02:53:00 am
content: I have encountered plenty of weirdness with USB keyboards, especially having them not work in the BIOS. Usually they do work with Windows though.You might try connecting it to a rear port via a USB hub.

author: mmagin
author_rank: Frequent Contributor
timestamp: September 10, 2013, 03:34:39 am
content: If for any reason you find yourself wanting to spend more on a small-footprint keyboard, I can highly recommend these:http://www.pfusystems.com/embedded-keyboard/hhkb/index.htmlThey seem to be up to about $100 now, but they're good quality. I've used two of them for 6 or 7 years (one at home, one at work.)

author: Psi
author_rank: Super Contributor
timestamp: September 10, 2013, 04:12:44 am
content: Or get this one for US$1090http://www.artlebedev.com/everything/optimus/popularis/

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: September 10, 2013, 04:14:47 am
content: if you change the keyboard setting in bios to USB keyboard support unplug your old one.Is your old keyboard USB or PS2 (green = mouse purple = keyboard) ? ,if its PS2 then you might not be able to use the usb keyboard to get into the bios again, you would have to plug the old PS2 keyboard in, or buy a usb to ps2 connector :http://www.ebay.com/itm/USB-FEMALE-TO-PS2-MALE-Adapter-Converter-keyboard-MOUSE-/170542764941?pt=LH_DefaultDomain_0&hash=item27b524138d

author: rexxar
author_rank: Frequent Contributor
timestamp: September 10, 2013, 05:32:08 am
content: Hm, maybe the ports on the back of your computer go directly to the chipset, and the ones on the front are on a hub? Though, I'm not sure what difference that would make. I agree with everyone else, you should take a peek inside

author: dr_p
author_rank: Frequent Contributor
timestamp: September 10, 2013, 06:56:05 am
content: Quote from: xrunner on September 10, 2013, 12:21:46 ambut does it work ok in rear ports if you plug it in AFTER logon? like while windows is running.

author: xrunner
author_rank: Super Contributor
timestamp: September 10, 2013, 01:05:27 pm
content: Quote from: dr_p on September 10, 2013, 06:56:05 amSometimes.I said in the OP that I tried all the rear ports that are directly attached to the MoBo. It still acts weird but other devices such as my SDR dongle and wireless mouse transceiver work perfectly. Yea I can look inside (I built the PC myself) but it's not going to tell me anything really. All the manual says it that the MoBo has additional 4 pin ports you can attach more USB devices to and it shows where they are on the board. I used two of them to run to the front ports on the case.There is nothing in the manual or bios that differentiates any of the ports from one another. I'll keep playing with it but it's a pain in the ass to keep changing to different ports, rebooting, and seeing what happens. At some point I'll just have to say "It is what it is" and just use a front port and go on with life.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: September 10, 2013, 03:13:03 pm
content: Is your old keyboard a PS2 or USBand what model/part number is the motherboard .

author: xrunner
author_rank: Super Contributor
timestamp: September 10, 2013, 06:36:07 pm
content: Quote from: fluxcapacitor on September 10, 2013, 03:13:03 pmI found the problem. The KB USB connector has some internal flaw. If I push or pull the cable near the end the right way it disconnects from the computer, and I can get it to re-connect if I again push it a certain way. Somehow it must hang the right way when connected to the front ports.Now the question is do I cut off a connector from a spare cable and try to fix it myself, or send it back to Hong Kong? I sent the seller a message that it has a flaw, let's see what he says abut it.I could also just cut off the plastic shell and take a look at how the wires are connected to the USB plug. Might make a good pic for the thread. I'm pretty sure a wire is just not crimped or soldered correctly. I'm game if you think I should ...

author: dfmischler
author_rank: Frequent Contributor
timestamp: September 10, 2013, 07:00:54 pm
content: You should. Beats sending it back, waiting weeks, and getting another one, maybe with the same problem.

author: ablacon64
author_rank: Frequent Contributor
timestamp: September 10, 2013, 07:06:50 pm
content: Quote from: xrunner on September 10, 2013, 06:36:07 pmI had a problem with a diagnal cutter bought from China, the seller sent me a new one and told me I could get rid of the defective one, no need to send back. If the seller asks you to return, then I think it's better to fix it yourself.

author: xrunner
author_rank: Super Contributor
timestamp: September 10, 2013, 07:08:13 pm
content: Quote from: dfmischler on September 10, 2013, 07:00:54 pmI agree.Well I dove in and let me tell you, that plug is potted to themax. Essentially non-repairable, but I got to the connectors, and sure enough the white wire (data +) popped right off the end. The red wire don't look too good either. I have plenty off spare USB cables so I will just cut off the end and wire it to the KB connector. Hopefully the color coding is the same.

author: pickle9000
author_rank: Super Contributor
timestamp: September 10, 2013, 07:35:40 pm
content: Wire colour codes china rarely match so make sure you use your meter to verify the correct connection. Also if the wire on the scavanged cable is good consider running it directly into the keyboard, it makes for a neater job.I like to use thin more flexible cable for keyboards because I tend to move them and the wire knocks things over.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: September 10, 2013, 09:08:42 pm
content: The pinout looks ok.You can get usb sockets on ebay,or use a spare usb cable from something else and solder it at the keyboard side .Anyway,glad you found the problem.http://pinouts.ru/Slots/USB_pinout.shtmlhttp://www.ebay.com/itm/10pcs-Type-A-Male-USB-4-Pin-Plug-Socket-Connector-Plastic-Cover-/271249806358?pt=LH_DefaultDomain_0&hash=item3f27bf9416

author: xrunner
author_rank: Super Contributor
timestamp: September 10, 2013, 09:47:18 pm
content: Quote from: pickle9000 on September 10, 2013, 07:35:40 pmIt would be neater that way but I just did a simple splice. I matched up the colors and lo and behold the problem is now gone.If the Ebay seller decides to send me another one without requiring a return I'll have two, if he wants a return I'll just tell him I'll fix it myself. But normally they don't want any negative ratings so they will pretty much do whatever to satisfy the customer.Anyway, thanks for all the suggestions, on to the next adventure.

author: xrunner
author_rank: Super Contributor
timestamp: September 11, 2013, 11:43:09 am
content: Reply from Ebay seller -Quote

author: amyk
author_rank: Super Contributor
timestamp: September 11, 2013, 11:54:18 am
content: I still prefer PS/2 keyboards, if for nothing other than the fact that they tend to require much less fussing around to work and can easily be interfaced to microcontroller projects.

author: AlfBaz
author_rank: Super Contributor
timestamp: September 11, 2013, 12:44:17 pm
content: Quote from: amyk on September 11, 2013, 11:54:18 amSo I guess your not big onwirelessusb keyboards then

author: westfw
author_rank: Super Contributor
timestamp: September 11, 2013, 05:25:35 pm
content: Cable terminations can be a real problem in "random" appliances. I've had several iPod cables go bad, and when dissected the failure was due to poor connections (easily shortable, for instance) or (more often) inadequate strain-relief leading to broken wires. I'd blame this on cut-rate manufacturers, but I really don't have much evidence that genuine brand-name products are any better.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: September 11, 2013, 05:55:22 pm
content: I've had an $80 mechanical keyboard fail because the internal strain relief on the USB cable wasn't up to snuff, causing the cable to break, causing intermittent loss of connection and eventually total death. I want to put a new USB cable in it eventually, but can't get the housing open...

author: xrunner
author_rank: Super Contributor
timestamp: September 12, 2013, 11:22:27 am
content: Sent them a pic of the USB connector and got this back."will can take it work well" ?Quote

author: rexxar
author_rank: Frequent Contributor
timestamp: September 12, 2013, 05:28:33 pm
content: Quote from: xrunner on September 12, 2013, 11:22:27 amWow. Just...wow.Looks like they just pasted from google translate.