My CUV4X-V had this problem. It was working great for about 3 weeks, until I tried to plug in a new-old-stock keyboard. I'd get stuttering input, and it was unusable. USB port worked for a few days, and then that failed as well.

I found this thread and pulled off my C151 capacitor and bam, everything is working fine again!

Thank heavens for website like this and for people posting these findings!!

I dug out (2) old CUSL2 m/cs from the loft as I need something with a 'real' floppy disk interface.

Needed a lot of tarnish cleaning from contacts but worked OK but after a while the keyboard stopped responding. Tried lots of things and eventually left it for the day. Next day it was working again??????
but in the mean time the IDE interface stopped working - I now think a faulty Disk has killed the FW82801BA Northbridge - orderd one off eBay and will try replacing just for the hell of it.
This disk causes a scrolling 'H' on the screen on boot up. A different disk passes the POST test but then hangs. The IDE interface and keyboard interfaqce are both on the same chip................

In the meantime the second machine.
Also needed lots of cleaning.
(They have both been in the loft for many years and damp seems to have got at them 🙁 ) Some rust on the printer port.

Straight off the bat, the keyboard was misbehaving causing the BIOS to make funny noises. After a few minutes - keyboard not present error every time.

That was when I found this website. Tested C151 and the segment on the keyboard connector had a low resistance (approx 1KOhm) on a digital meter - not showing dead short maybe because the test voltage is not very high - didn't try my old analog meter.
Checked the other machine and there was an OC reading.
Removed C151 and hey presto the keyboard is working again - phew!

Was now able to boot into Windows XP and the USB mouse was not working. Tried cleaning the USB port connections - no change. Added an extra USB card and the mouse was OK.
I then spotted between the USB port and the printer port there is a jumper marked USBPWR (USB power I guessed) I removed this and cleaned the contacts and jumper and now OK again - another phew!!
I assume this is for when all your USB devices are externally powered.

One 256MB RAM sticks is not working. Have cleaned it but will try more intensely.

I am amazed at how fast this 933MHz thing is running 32 bit Windows XP. If ir could I'm guessing Windows 11 would take about 3 weeks to load.

More to follow as this progresses.
As an aside a stupidity. I had the case propped up while testing (the one with the faulty IDE) and it slipped with a USB cable plugged and and has broken one half of the dual USB socket - now also ordered from eBay. Doh!

Whoah! This is exactly what has been happening to me.

I have an ASUS CUV4X which I had gotten for cheap on ebay and which was in storage till I got my other stuff for the build. Initially everything seemed fine and I even got Win 95 on the system. However I started having weird input issues(especially with the Ps/2 mouse not being detected on the Win 95 OS) and a wheezing sound from the mobo speaker. When I would take all the stuff out and reboot it would POST for sometime and then back to the wheezing sound again. After turning the system off and maybe after half an hour or so, everything would seem to go back to normal and then the same issues would again come back.

I will try this fix today and update my status if I get everything working. All I can say after all of this is that suspiciously cheap ASUS CUV4x mobos should be avoided.

Ok I implemented the fix but now the PS/2 part is not working at all. The board POSTs and then complains of no KB error. I did manage to pry open the C151 with a scalpel. I dunno if that caused some issues with the rest of the PS/2 connection. I have attached how my mobo looks after the operation.

Hans Tork wrote on 2025-09-19, 18:25:

Ok I implemented the fix but now the PS/2 part is not working at all. The board POSTs and then complains of no KB error. I did manage to pry open the C151 with a scalpel. I dunno if that caused some issues with the rest of the PS/2 connection. I have attached how my mobo looks after the operation.

Details

The attachment asus1.jpg is no longer available

The attachment asus2.jpg is no longer available

The attachment asus3.jpg is no longer available

After a bit more cleaning and scrubbing, since the keyboard is still failing to get registered in the POST.

The attachment asus4.jpg is no longer available

Hate to say it...

but

That removed component

is not C151
.
😒

nevermind. just looked at the other comments in this thread.
confusion due to people calling a resistor array a capacitor 😒

weedeewee wrote on 2025-09-19, 18:42:

Hate to say it... but That removed component is not C151 . :-/ […]
Show full quote

Hans Tork wrote on 2025-09-19, 18:25:

Ok I implemented the fix but now the PS/2 part is not working at all. The board POSTs and then complains of no KB error. I did manage to pry open the C151 with a scalpel. I dunno if that caused some issues with the rest of the PS/2 connection. I have attached how my mobo looks after the operation.

Details

The attachment asus1.jpg is no longer available

The attachment asus2.jpg is no longer available

The attachment asus3.jpg is no longer available

After a bit more cleaning and scrubbing, since the keyboard is still failing to get registered in the POST.

The attachment asus4.jpg is no longer available

Hate to say it...

but

That removed component

is not C151
.
😒

nevermind. just looked at the other comments in this thread.
confusion due to people calling a resistor array a capacitor 😒

Yeah I made it doubly sure before prying it open. I think it was also mentioned something with C, though barely legible. I do not have a soldering rod or even experience with soldering, so just did the thing with a scalpel. Honestly, this is first time I am even trying out stuff on a motherboard.

Interestingly enough, my P2B-DS experience these issues too, and I have found a cracked resistor pack near the Multi-IO chip, which I expect to be the keyboard controller as well. However, that pack seems to connect to the printer port pins of the Multi IO, so haven't really bothered (yet) to do something about it.

BUT; reading this thread, I looked at the backside of the PS2 connectors, where I didn't fint the mentioned capacitor array - here it's 4 separate capacitors. And look at one of them. (it measures 1.5 kOhm, albeit in-circuit, so might not be relevant - but that's too conductive for a capacitor).

Gonna try to replace it at some point.

H3nrik V! wrote on 2025-09-29, 11:16:

Interestingly enough, my P2B-DS experience these issues too, and I have found a cracked resistor pack near the Multi-IO chip, which I expect to be the keyboard controller as well. However, that pack seems to connect to the printer port pins of the Multi IO, so haven't really bothered (yet) to do something about it.

BUT; reading this thread, I looked at the backside of the PS2 connectors, where I didn't fint the mentioned capacitor array - here it's 4 separate capacitors. And look at one of them. (it measures 1.5 kOhm, albeit in-circuit, so might not be relevant - but that's too conductive for a capacitor).

Gonna try to replace it at some point.

Unfortunately the board`s PS/2 has stopped working altogether. I can use the USB though. I wanted it for a Win 95 build so probably gonna retire it and keep it in storage. Sad that it had the annoying issue.

Also I would say that removing that part with a knife might not be the best idea. I think I damaged some wiring(the board boots up perfectly even with that) during the operation. If I would I do it again I would try to desolder it very carefully.

wiretap wrote on 2021-06-10, 18:20:

It can be replaced. It is a 4 element capacitor array, 0612 size, 150pF. https://www.mouser.com/ProductDetail/Yageo/CA … fOWXyU […]
Show full quote

Justin1091 wrote on 2019-09-13, 18:53:

So after a month of using the PC and the keyboard without issues, it failed again yesterday. This time I couldn't even get past the keyboard error at POST.

Decided to take out the C151.. problem solved! I wonder how it gets bad over time and whether I should replace it. What do you guys think? They put it there for a reason obviously.

It can be replaced. It is a 4 element capacitor array, 0612 size, 150pF.
https://www.mouser.com/ProductDetail/Yageo/CA … fOWXyUeiw%3D%3D

They are kind of an odd component to solder -- I've done a few of them in the same package/size on other PCB projects. The keyboard connector may need to be removed if using a soldering iron. Otherwise, hot air with a tiny amount of solder paste on the pads may work better.

Yes, it is there for a reason, but without schematics,it would be hard to determine why. Looks like keyboard input signal decoupling/filtering.

Would these files help? You can also load this file \60-M6PGZ5-B3\PINS.ASC into Boardviewer