Missing some caps on Jetway V266 mobo

[berniedd]

A friend asked me to repair her motherboard. She says suddenly it won't even boot. It's a Jetway Socket 462 model V266B. She said some guy tried to fix it months ago but returned it still dead. Well, I took a look and some 1500 uF 6.3v caps were bulging. Looks simple enough. Unfortunately, the jerk who couldn't finish the job took off some caps and never bothered to replace them. So here I am with a repairable board and I don't know what value caps to put in for the missing stuff. Can someone out there with the same model mobo help me out? The missing ones are: the three large electrolytics beside a green torroid inductor and between serial port 2 and the processor socket; and two very large caps (their white circle outlines painted on the board are the largest of all on this mobo) beside the AGP video card socket.

As a corollary, am I safe if I replace these missing caps with 2200 uf 16 volt units? I've seen a few older motherboards with 25 volt caps. Why the need for 25 volt ratings? Computer power supplies put out no more than 12 volts.

[gonzo0815]

Re: Missing some caps on Jetway V266 mobo

You can either measure the voltage or just take some 16v caps. The 25v rated caps are only choosen to improve some critical parameter (ESR) instead to begin with higher quality caps.
Most skt 462 boards are equiped with abouth 6 2200uF 6.3v caps next to the cpu soket or at least with 4 3300uf caps.
If the silkscrean is indicating something thicker than 8mm, i think 2200uf should work fine.

[kc8adu]

Re: Missing some caps on Jetway V266 mobo

i would just stuff it with 3300@6.3 around cpu.
if the board has p4 power at vrm input those would be 1000-2200@16.

[berniedd]

Re: Missing some caps on Jetway V266 mobo

I've finished replacing all above mentioned caps (2200 uf, and 1500 uf and 1000 uf)), the large caps around the processor and the video card slot, even a few 470 uF caps scattered here and there. I put in my old 1.1 GHz Duron processor, 256 MB SDRAM I know to be good, and an AGP video card.The thing now powers up and the cpu fan spins, but I don't get a video output. Hmmm, Ok I removed the AGP card, and put in a PCI video card, but still no video. Any ideas, guys?

[Spacedye69]

Re: Missing some caps on Jetway V266 mobo

OK, I'll ask. Did you reset the bios?

[dood]

Re: Missing some caps on Jetway V266 mobo

Make sure there isn't a jumper for 100/133mhz FSB. If there is, it needs to be set to 100 for that duron.

[berniedd]

Re: Missing some caps on Jetway V266 mobo

OK, I'll ask. Did you reset the bios?

Yes, I did reset the BIOS using the shorting jumper on the board, then brought it back to the original position. Thanks for the comment.

[berniedd]

Re: Missing some caps on Jetway V266 mobo

Make sure there isn't a jumper for 100/133mhz FSB. If there is, it needs to be set to 100 for that duron.

Huh? All along, I thought the Duron 1.1 GHz took a 133 MHz FSB. I'll download a manual tomorrow and take a peek at what all the settings should be. Thanks.

[berniedd]

Re: Missing some caps on Jetway V266 mobo

Hey dood, you're absolutely right. The Duron didn't use a 133 MHz FSB till it was offered in the 1.4 GHz speed rating.

Guys, I finally got this mobo to run well. I don't have an ESR tester so I replaced ALL caps that were 470 uF and larger in capacity. All in all, the replaced caps totaled 24, almost all of them G-Luxons !! Many of these looked good from the outside.

[Phenos]

Re: Missing some caps on Jetway V266 mobo

I recapped it this way, Dont look at the black dots they are just markers.
Original caps where 7X GSC 1500uF on the VRM output.

[berniedd]

Re: Missing some caps on Jetway V266 mobo

Phenos, I see you haven't yet finished the job. I see no caps on the circles marked P3, P4 and P5. Or did you intentionally leave them unpopulated, considering you used 3300 uF caps instead of the 2200. Thanks for the input.

[Phenos]

Re: Missing some caps on Jetway V266 mobo

Those caps are connected paralel to each other, i increased the capacity to compenstate for the 2200uF capacitors. the 16Volt capacitors can be changed to 6.3volt because this mainboard is powered with 5volt. Mainboard works flawless.