ps/2 mouse randomly shooting over screen - Page 1
Forum section: electronics / projects

author: paul_g_787
author_rank: Frequent Contributor
timestamp: December 31, 2020, 03:50:24 pm
content: OK so this is a weird issue. I have been using the same PS/2 mouse since 1999, but the last few days it has started randomly shooting all over the screen clicking at things on it's own when I am in the middle of doing something!!First thing I did was use another mouse of the same model from work (brand new old stock) and it is doing it with this one too!! So I am sure the mouse is not faulty. Both Microsoft IntelliMouse 1.1a.Could this be RF interference of some kind? The cable on these mice is not shielded.It is driving me mad that it has suddenly become a problem.

author: m k
author_rank: Super Contributor
timestamp: December 31, 2020, 05:59:44 pm
content: Do you have a new mouse mat?

author: janoc
author_rank: Super Contributor
timestamp: December 31, 2020, 06:36:04 pm
content: RF interference maybe but not very likely - PS/2 uses 5V signalling, that gives a ton of noise margin, plus those signals are pretty slow. Unless you have a HAM radio transmitter right next to it I doubt it would be RF. That would probably kill your keyboard at the same time (same kind of signal, cables are not shielded neither).Do make sure you have cleaned the mouse first (especially if that is a mouse using a ball and rollers - those do pick up a ton of grime) and that there is no stray light getting in it.Long time ago I had a mouse that had a white translucent plastic body and when sunlight hit it just right, it was messing with the optical sensor inside! This can easily happen with an old ball mouse that uses optical encoders but even newer mice using camera-like sensors aren't immune to it.

author: Kleinstein
author_rank: Super Contributor
timestamp: December 31, 2020, 07:27:01 pm
content: Is there some other equipment connected to an RS232 port or similar. Windows may mistake this signal for a second mouse. I just had that last weak. It may even be interference or failure at an unused port. It may hep to disable an unused RS232 port.

author: Renate
author_rank: Super Contributor
timestamp: December 31, 2020, 07:49:30 pm
content: I think Kleinstein has hit the nail on the head.Go to the Device Manager (devmgmt.msc) and see if you have a "Microsoft (TM) Ballpoint (TM) Mouse (TM)".Windows lives to identifyANYTHINGplugged into a serial port as a mouse.(That's even though serial mice is a concept long dead.)You can't even get around this by deleting all the junk out of msmouse.infYou can disable serenum but it breaks something too.I've tried. You can't tell Bill Gates, "I solemnly swear that I will never use a serial mouse or require it to work ."A GPS module will have this effect.Unrelated: Some HID devices will break an AMI BIOS because it doesn't know the difference between a keyboard and another kind of HID device.

author: Bud
author_rank: Super Contributor
timestamp: December 31, 2020, 08:06:49 pm
content: Could be your keyboard too. Try a different keyboard.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 31, 2020, 08:16:27 pm
content: I assume you are connecting your mouse via a USB to PS/2 adapter, is that so? If so, I would check the USB Hub. I had an issue with my PS/2 keyboard that, whenever I had a large number of ports connected (it is a 7 port powered Hub), the keyboard would start to develop some erratic behaviour. In the end I changed the Hub power supply for a much more powerful one and I haven't had any instabilities.BTW, the hub I have is a good quality one from Dlink, not a bargain bin model. That may also make a difference.

author: paul_g_787
author_rank: Frequent Contributor
timestamp: December 31, 2020, 11:26:36 pm
content: Quote from: m k on December 31, 2020, 05:59:44 pmBeen using the same one for 5 years. I also tried using no mat and the issue was the same.

author: paul_g_787
author_rank: Frequent Contributor
timestamp: December 31, 2020, 11:28:13 pm
content: Quote from: janoc on December 31, 2020, 06:36:04 pmIt is a ball mouse with optical encoders. I have dismantled it and cle4aned it, but as pointed out a brand new mouse has the same issue.

author: paul_g_787
author_rank: Frequent Contributor
timestamp: December 31, 2020, 11:29:22 pm
content: Quote from: Kleinstein on December 31, 2020, 07:27:01 pmI haven't got any other serial devices connected at present apart from the ps/2 keyboard.I am also using Ubuntu 20.04

author: paul_g_787
author_rank: Frequent Contributor
timestamp: December 31, 2020, 11:30:23 pm
content: Quote from: Bud on December 31, 2020, 08:06:49 pmI just tried a USB keyboard and the issue was still present with the mouse.Using a USB mouse I have no issue.

author: paul_g_787
author_rank: Frequent Contributor
timestamp: December 31, 2020, 11:32:16 pm
content: Quote from: rsjsouza on December 31, 2020, 08:16:27 pmNo the mouse is PS/2. I have an Asus P8B75-V Motherboard which has seperate keyboard and mouse PS/2 sockets.

author: Distinctly Average
author_rank: Contributor
timestamp: December 31, 2020, 11:53:18 pm
content: Could you try an USB mouse? I’ve seen this with a faulty PS2 port. In my case it was a very old cap on the motherboard that had curled up its toes causing the symptoms you are getting.

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 01, 2021, 12:02:54 am
content: Have you tried a PS/2 to USB converter?

author: BravoV
author_rank: Super Contributor
timestamp: January 01, 2021, 07:40:02 am
content: Quote from: paul_g_787 on December 31, 2020, 03:50:24 pmHave you check internally for leaking electrolytic cap ?

author: SeanB
author_rank: Super Contributor
timestamp: January 01, 2021, 08:57:55 am
content: Intellimouse 1.1 unplug the green adaptor and use it via USB, see if it still does this. If not them motherboard failing, or if continues either still motherboard, or mouse capacitors have died, seeing as they are now over 20 years old, and MS did not expect them to last that long. Try to use the optical version, with the PS/2 connection and see if the issue persists, and otherwise change to USB.I use the optical version with the same OS, and have no issues, even have had 2 connected at the same time no issues, only time it moved was when the cat was playing with it.

author: m k
author_rank: Super Contributor
timestamp: January 01, 2021, 06:32:49 pm
content: Quote from: paul_g_787 on December 31, 2020, 11:29:22 pmI thought the mouse is optical.Anyway, using other mouse and having same issues is clearly something internal.You can test it so that open a full sreen drawing software and leave the machine alone.If the mouse does its own boot older CD/DVD Ubuntu and try the same.If it's still doing its own it's most likely a hardware problem and you better just give up with the PS/2 port.Hacked OS is always a possibility too but then extra happenings should be at least somewhat rational, if irregular mouse movements are not a smoke screen.(theoretical, far cry, pass)

author: paul_g_787
author_rank: Frequent Contributor
timestamp: January 02, 2021, 10:04:27 pm
content: An interesting behaviour I have noticed. The mouse does not have an issue when I leave it alone, only when I am using it will it start playing up.Also, when it plays up, the cursor does everything at once, moves horizontal and vertical (all over the place) left clicks, right clicks, middle clicks, scrolls up and scrolls down.However if I lift up the mouse off the mat / desk it stops instantly!!I have tried wiggling the wire about and the connectors but cannot make it do this.I have also tried the brand new mouse again (same model) and the same with this, if I lift up the mouse during the problem it stops.How odd right?

author: tszaboo
author_rank: Super Contributor
timestamp: January 02, 2021, 10:26:01 pm
content: Quote from: Renate on December 31, 2020, 07:49:30 pmOh, I've seen this. It was a custom datalogger with a FT232, connected to a computer of an EE, at work, he was talking to me. In the middle of his sentence, his mouse started to go haywire, going in insane speed, clicking on everything, starting programs. We were just looking at it for like ten seconds, and I must admit, that was probably the hardest I ever laughed.

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: January 02, 2021, 10:33:14 pm
content: I recall a similar behaviour, caused by plugging the mouse and keyboard into opposite PS/2 connectors (my devices pre-dated the green and purple colour code so this was an easy mistake to make).m k's suggestion of a Linux boot USB is a good way to narrow down the issue. Could just boot the last USB you used to install your distro, if you still have it.

author: m k
author_rank: Super Contributor
timestamp: January 03, 2021, 05:35:07 pm
content: Quote from: paul_g_787 on January 02, 2021, 10:04:27 pmI remember that there was a third wheel or roller inside the ball cup.If that is on/off switch then happenings are more rational, connection type is syncronized and clock is open collector.Means that the clock goes off when mouse is lifted and so no data, good or bad, is going in.Have you tried them devices in wrong ports?

author: paul_g_787
author_rank: Frequent Contributor
timestamp: January 04, 2021, 03:02:27 pm
content: Quote from: m k on January 03, 2021, 05:35:07 pmI just tried that, keyboard connected to green PS/2 port and mouse connected to Purple. And neither my keyboard and mouse are detected in the BIOS or OS. So have switched them back.

author: m k
author_rank: Super Contributor
timestamp: January 05, 2021, 08:32:38 pm
content: Not so many options left.It seems you eighter need to repair that motherboard or accept the upgrade.If accuracy is the issue then new USB mice can be guite good.Windows can also adjust movements quite a bit.Nowadays zoom has also taken care of some of the issues.Also, for accurate optical mouse use you need to keep your mat pictures as stochastic as possible.

author: A.Z.
author_rank: Super Contributor
timestamp: January 06, 2021, 08:14:34 am
content: I'd start by checking if the issue is hw or sw, to do so, download the iso for a "live" linux distro, burn it on a CD/DVD (or a USB stick) and boot the system with it, then check if the mouse is still acting, if this isn't the case then the hw is most probably ok and the issue is due to sw (e.g. multiple conflicting mouse drivers or the like)

author: paul_g_787
author_rank: Frequent Contributor
timestamp: January 09, 2021, 04:50:56 pm
content: Quote from: A.Z. on January 06, 2021, 08:14:34 amGood suggestion. I booted to my windows 7 installation and it is doing it on there also. I also stuck my ubuntu Installer USB in and it is still having problems there.I have just borrowed a Logitech PS/2 mouse from work and it also has the problem!!I am gonna try my mice on my work PC too to rule them out.Possibly motherboard??I had a look and there are no bulging caps I can see.However, the issue is so random. I would assume if it was the motherboard the fault is most likely to be present all the time, but yesterday the mouse didn't play up at all and I was using the PC for 6 hours. Today however, within 5 minuted of bootup I had the problem a couple times but not since.

author: A.Z.
author_rank: Super Contributor
timestamp: January 09, 2021, 06:25:34 pm
content: ok, now we may exclude 50% of the causes, I mean, given the tests, it shouldn't be a software issue, so the focus is on the hw, I'd start by performing a careful clean and also unplug, clean and reseat all the boards (including. RAM sticks) and connectors, if possible also check the power supply voltages and ripple, then it could also be a good idea running a system test (memtest and/or the like) for 24 hours

author: Renate
author_rank: Super Contributor
timestamp: January 09, 2021, 08:17:12 pm
content: If you're really enamored of the PS/2 paleo-crap, just make a PS/2 to USB converter.

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: January 09, 2021, 09:27:50 pm
content: Quote from: Renate on January 09, 2021, 08:17:12 pmThat seems needlessly harsh. People have reasons for using certain hardware ... could have special significance like a gift from a now dead person, could have just the right ergonomics, etc. This USB adaptor suggestion can be made (and already has been made by others in this thread) without rubbishing OP's judgement.

author: HendriXML
author_rank: Super Contributor
timestamp: January 09, 2021, 11:04:11 pm
content: I used to have a ball mouse that stopped working at certain moments..it couldn't handle sunlight getting through the enclosure. Took some while to figure it out..

author: Miti
author_rank: Super Contributor
timestamp: January 10, 2021, 02:00:51 am
content: Have you upgraded your lights from incandescent to LED?

author: coppercone2
author_rank: Super Contributor
timestamp: January 10, 2021, 05:44:59 am
content: high noise floor causing the sensor to be wonky when it starts sending outputs I thinkbad regulationmakes sense to investigate because it might blow a cap or take out a power rail if you ignore it and take out the system in numerous ways, partial short & thermal overload etc

author: paul_g_787
author_rank: Frequent Contributor
timestamp: January 11, 2021, 07:31:02 pm
content: My god I have worked it out!!!!!It is my 4G phone causing the issues!! When my phone is on my computer desk and when the phone 'pings' the mast it makes the mouse go haywire!! This is why it was happening at work too, because my phone was in my pocket.Basically like when you put the phone near a radio and it goes "nghh nghhh nhgghhh"If I keep my phone more than about 1m away from the mouse it is fine!!So 3 different mice on 2 different PCs are getting interfered with by my phone. So can anyone shed some light on this??Interestingly the keyboard (also PS/2) never gets affected??

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: January 11, 2021, 09:49:21 pm
content: Fascinating failure mode!Mice are generally not shielded (at least they weren't back in the day), so significant lengths of the PS/2 wires are exposed to EMI. You may be able to solve this by making a partial Faraday cage inside the mouse, e.g. using conductive copper EMI tape or fabric tied to the PS/2 shield.

author: HendriXML
author_rank: Super Contributor
timestamp: January 11, 2021, 10:46:06 pm
content: Quote from: paul_g_787 on January 11, 2021, 07:31:02 pmI thought my my "sunlight" mouse experience was almost too different to mention, but it has some similarities

author: Distinctly Average
author_rank: Contributor
timestamp: January 12, 2021, 12:13:47 am
content: It is quite common for the solder joints on the PS2 socket to break down. Re-flowing them might help.

author: coppercone2
author_rank: Super Contributor
timestamp: January 12, 2021, 02:59:08 am
content: it could be weakened capacitors or driver circuits / increased noise margin that suddenly made it more vulnerable to RF, or cracked ferrite or bad electrical connection.Odd that this would just now happen. unless you just never put your phone there to begin with. This is a common problem in hand held multimeters next to walki talkies actually (effects maintenance people). The fix is often just a metalized plate right behind the meter, not a full enclosure or anything drastic. If you take apart a half decent cheap multimeter you will often see a 4x3 inch metal card attached to the inside of the back cover with a spring or contact on the PCB that touches it. You might be able to solder a copper spring to the ground plane and put copper tape on the inside of the mouse or something to try the same fix.Or the phone might have a problem with the RSSI for whatever reason and increase broadcast power (i.e. something changed with the cell tower it connects to, or the phone is malfunctioning). I believe they try to tune output power to maintain battery life and reduce airways pollution when they can.

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 12, 2021, 04:09:22 am
content: Quote from: coppercone2 on January 12, 2021, 02:59:08 amEven one of the most reputable brands of multimeter has been affected.

author: A.Z.
author_rank: Super Contributor
timestamp: January 12, 2021, 10:16:17 am
content: Quote from: paul_g_787 on January 11, 2021, 07:31:02 pmCheck if the PS/2 mouse connector grounding (ext shielding and pin #3, seehttps://en.wikipedia.org/wiki/PS/2_port) is ok, then you may try adding some choke(s) to the mouse cable to see if they'll solve the issue

author: Renate
author_rank: Super Contributor
timestamp: January 12, 2021, 08:26:13 pm
content: Quote from: NiHaoMike on January 12, 2021, 04:09:22 amI have a cheapy Velleman that went crazy within 1 meter from portable gasoline generator ignition.Does your PS/2 mouse have a shielded cable?The regular USB 1.0 isn't shielded.

author: niconiconi
author_rank: Frequent Contributor
timestamp: January 13, 2021, 09:58:27 am
content: Quote from: I wanted a rude username on January 11, 2021, 09:49:21 pmWrapping the cable on a ferrite choke is also a "just try and see" solution, perhaps a turn or two is enough to fix it. Ideally it should be close to the mouse, but it makes the mouse rather inconvenient to use in this particular instance...

author: m k
author_rank: Super Contributor
timestamp: January 13, 2021, 11:35:40 am
content: Quote from: paul_g_787 on January 11, 2021, 07:31:02 pmSometimes it's a bit less easy to see what is relevant.Intermittent stuff is generally the harder end.QuoteYour phone is throwing more energy towards your mouse than before.Are you aware how it has used its frequencies earlier?It may have 2G and 3G is going out.Force it using only one frequency area.

author: paul_g_787
author_rank: Frequent Contributor
timestamp: January 14, 2021, 04:05:23 pm
content: OK, so I read all your comments and took them on board and have done a bit of testing to rule out a few things.I firstly borrowed a USB to PS/2 converter from work and connected my mouse to my PC using USB. the problem is still present proving it is not the PS/2 port on the motherboard. (Good news).I also tried this with the other two mice I used before, and same as before all three were playing up and experiencing the same problem.The problem being my phone interfering with them as stated before for those just tuning inMy phone is 4G, I switched it to 2G and 3G only and there is no issue at all in these modes. So the issue is apparent with the 4G frequencies causing interference in the mouse.Interestingly I have had the same mouse for 22 Years and this phone for 1 and a half years and before that another 4G phone and never experienced this issue until recently.I have worked out how I can replicate the problem intentionally:I put my phone on my desk (or within about 1m of the mouse such as in my pocket). Then phone it using the landline. And the cursor goes crazy!!!!!!! clicking everything in sight and it even completely locked up my PC a couple of times.So Yesterday I borrowed a family member's iPhone 11 which they got in the summer so it is brand spanking new! And the same thing with that phone, I place it by the mouse and phone it from the landline and it causes my mouse to go crazy!!I repeated these tests with all 3 mice and exactly the same results.So this, in my opinion, has certainly proved it is not the PS/2 on the motherboard and not the phones or mice individually at fault.So I can only conclude that the 4G frequencies specifically are causing some kind of EMI with the frequencies used by PS/2.Now interestingly none of the mice or my keyboard have shielded cables (I have never in my whole career seen a shielded PS/2 cable), but the keyboard never has an issue. The keyboard also has no metal in the casing, just ABS plastic. (I took it apart last year when I spilled tea on it).So what I cannot understand is why would the issue only affect mice and not keyboards? What is the difference in PS/2 communication used for a keyboard and PS/2 used for a mouse??What do you all think?

author: m k
author_rank: Super Contributor
timestamp: January 14, 2021, 06:17:40 pm
content: Yes, hardware is ok.One possibility is that any phone there has never used frequencies they use now.Maybe the tower has some new parts.Since only mice are affected it can be something how those communications are made inside those devices.If you like to test that you should find a mouse that is from time before Microsoft mouse.Premise there is that then the communication chip was different.

author: paul_g_787
author_rank: Frequent Contributor
timestamp: January 15, 2021, 02:21:14 pm
content: I am not so sure I am not looking at two problems here.It did it again today, and I discovered, as before, if you lift the mouse so the ball is not touching the table it stops. As soon as I put it down again, or touch the ball with my finger, it resumes zooming and clicking everything??This is such a strange intermittent issue.As before, I rang my mobile (while near the mouse) from the landline and it makes it go haywire, then again lifting the mouse up so the ball is not in contact stops it!! So I can replicate the behaviour!So it only picks up the 4G interference when the ball is in contact with the encoders???Very confused right now.

author: SeanB
author_rank: Super Contributor
timestamp: January 15, 2021, 03:12:18 pm
content: Very likely the ball is the issue, as it probably is getting close to being a quarter wavelength at the Rf from the phone, or is adding just enough extra capacitance to the long wire antenna that is the cable. Easiest is, as you have opened the mouse, to take some ferrite beads from old keyboard cables and put them on the cable at the mouse end, so there is now a RF block in the mouse as well, which the keyboard likely has on the leads inside already. You might find on the board 4 wire links for a ferrite bead that are not fitted with the bead, but probably just the ferrite on the cable inside will do the job. Otherwise solder some small SMD 10-22pf capacitors across the 2 data pins right on the board, connecting the data lines to the ground of the board, and put the same size chip ceramic, any value from 10n to 100n on the power pin should help. After that a small strip of self adhesive copper strip covering most of the inside of the case, connected via a braid to the ground pin, will also help.

author: paul_g_787
author_rank: Frequent Contributor
timestamp: January 19, 2021, 05:00:33 pm
content: Just had a look at the Micro$oft mice and there are two spots on the board, unlabelled, populated by wire links, in series with the data pins of the cable. So perhaps intended for ferrite beads.Thinking about ordering a pack of them to try.However, I took the top off my original mouse and when I manually spin the horizontal encoder it sometimes 'stutters'. Not sure why. Same behaviour on the brand new one.If I ring my mobile from the landline in the vicinity, and rotate the plastic shaft of the horizontal encoder at the same time with my finger this causes the mouse to play up as before. No issues when trying the same thing with the vertical encoder.The encoders are both optical; an LED, a photo transistor (I think) and a plastic shaft with a 'gear' on it. So as the 'gear' rotates it blocks the light between the LED and sensor.So something on the horizontal encoder circuit maybe?Same results with the brand new microsoft mouse!! So it is replicable at least.

author: m k
author_rank: Super Contributor
timestamp: January 21, 2021, 11:43:49 am
content: Fold a gum wrapper, aluminium inside, and start blocking.Was there a time when mouse balls became much lighter?

author: SilverSolder
author_rank: Super Contributor
timestamp: January 21, 2021, 02:15:00 pm
content: Try a laser mouse instead - perhaps less prone to interference than the ball-type?

author: Terry Bites
author_rank: Super Contributor
timestamp: January 21, 2021, 05:56:50 pm
content: Treat yourself to a new mouse and relax.