Asrock K7VT4A Pro

[amartolos]

Hi,

The above-mentioned MB started to give random blue screens after a few years of service, so after inspection it turned out that the UCC KZG 3300uF/6.3V caps around the CPU were bloated. I intend to replace them with Panasonic FM with the same capacitance/voltage rating.

In addition, I intend to replace also the LTec's LZP 1000uF/6.3V with Panasonic FM and the Teapo 100uF/16V with Nichicon PW, just to be on the safe side. There are some UCC KZE capacitors, which are reported to be OK.

This mainboard was used with an Antec SL350P power supply, discussed here.

I have an Athlon XP 2400+ CPU, and I used as "software cooling" the S2KCtl application, which sends the "Halt Disconnect and Stop Grant Disconnect" commands to the CPU when idle, resulting in a lower power consumption. As far as I understood, this puts a great stress on the power regulation, so my question is whether it's wise to use this method again when the system is (hopefully) running.

Also, please have a look and tell me if I'm about to do anything wrong.

Here is a picture of the mainboard:


Thanks!

Dan

[yyonline]

Re: Asrock K7VT4A Pro

6.3V 3300uF Panasonic FM capacitors are 12.5mm in diameter. The KZG are 10mm in diameter. The larger FM capacitors may be difficult to squeeze in there.

Likewise, 6.3V 1000uF FM is 10mm diameter, while the original Ltec are 8mm diameter.

If your replacements will fit, I see no issues. If they won't fit, you'll have to select a different brand/series as a replacement.

[larrymoencurly]

Re: Asrock K7VT4A Pro

I have one of those mobos, and after 3-4 years the 3300uF OST caps were still OK (measured for ESR), but 3 of the 1000uF Ltecs in the memory voltage regulator and around the north bridge popped -- CE10, CE16, and CE17. All the other Ltecs measured OK for ESR.

Have you been able to get the S3 suspend-to-RAM to work? With my mobo the PSU fan keeps running in S3 mode.

[amartolos]

Re: Asrock K7VT4A Pro

yyonline, you are right. I will get some Rubycon MBZ caps for the 3300 uF from an eBay seller that seems to have a good reputation here. Ltec will be replaced by Nichicon HM (the 2000-2004 problem should be far back) and also for the Teapo I would get Nichicon VZ.

larrymoencurly, I did not try the S3 (I don't use it much), but I will see how it goes after recapping. Maybe it's an Asrock issue, as the other board, a 939Dual, also does not go into S3 mode (see also this discussion). My Asus at work has no problems with S3.

Thank you for posting.

[yyonline]

Re: Asrock K7VT4A Pro

Are you referring to the eBay seller egekecu? If so, his stuff is real. However, it is old stock. If you order Nichicons from that seller, be sure to check the date codes to be sure.

[amartolos]

Re: Asrock K7VT4A Pro

Yes, that's the guy. Thanks for the info! I will get only the Rubies from him, the Nichicons come from digikey. I hope they have a better turnover...

[amartolos]

Re: Asrock K7VT4A Pro

Just a quick update: capacitors replaced (even the small ones), and the board powers up gracefully and I am able to enter into BIOS setup. I hope I will be able to test it more when its PSU gets fixed...

[amartolos]

Re: Asrock K7VT4A Pro

So, after the full recap (4 UCC KZG 3300uF/6.3V replaced with Rubycon MBZ, 15 LTec LZP 1000uF/6.3V replaced with Nichicon HM, 4 Teapo 100uF/16V replaced with Nichicon VZ, the 4 UCC KZE left in place), the system does not freeze or BSOD anymore (the PSU was also recapped). It ran prime95 for more than an hour, so I hope it is well now

The STR feature does not work in Windows XP.

[c_hegge]

Re: Asrock K7VT4A Pro

Nice work. You're lucky the KZGs bloated when they failed. Often, they don't.

[amartolos]

Re: Asrock K7VT4A Pro

>>Nice work. You're lucky the KZGs bloated when they failed. Often, they don't.<<

Thanks. Actually, after the system started to crash, at some point I opened the case to clean the dust away. It was only *then* that I noticed the bad caps And my previous mobo died because of... cap plague.

larrymoencurly, if you're still interested in S3 sleep mode, it works! I tried it on another Asrock mainboard, but it should work on this one as well. Read the full story here. The shorter version: download this program from Microsoft, run it as

dumppo.exe admin minsleep=s3

and enjoy silent standby

[amartolos]

Re: Asrock K7VT4A Pro

Well... I spoke too early. The above mentioned trick, while it worked on my Asrock 939Dual-SATA2, does not work for this one and keeps going into S1. I'm still trying, though...

[momaka]

Re: Asrock K7VT4A Pro

I think it has to do with the CPU. If I remember correctly, those old AMD CPUs don't support S3.

[RJARRRPCGP]

Re: Asrock K7VT4A Pro

You must enable it in the BIOS.