Dimension 8400 with bad HN(M)'s

[yyonline]

Re: Dimension 8400 with bad HN(M)'s

Feel free to post pictures of what the "guy online" sends you. There are a lot of counterfeit caps floating around out there. I'd always recommend ordering from a trusted source, such as badcaps.net, mouser, or digikey. I'm not saying your source isn't reliable, but it can't hurt to check.

[iliiinieis]

Re: Dimension 8400 with bad HN(M)'s

I ordered from Mouser which is about 70 miles from me. Much to my surprise, I got them today and got them all replaced. However, upon reassembling the computer some strange things happened.

First thing as soon as I plugged it in was a loud high pitch noise that tapered off. Sounded like a camera flash charging only it was louder. The case was open so they may be why it was so loud but I bet this isn't normal.

2nd thing to happen was the fan went into jet mode. None of the new caps are puffed up and I replaced all the caps with any bulge at all.

This is what I replaced:

220uf 6.3v VP(M) replaced with same
470uf 16v VR(M) replaced with same
1000uf 10v HN(M) replaced with same
2200uf 10v HM(M) replaced with same
2200uf 6.3v HN(M) replaced with same except 10v

Any ideas?

[yyonline]

Re: Dimension 8400 with bad HN(M)'s

Did you pull the battery off the board when you were recapping it? If not, you might want to pull the battery out for a few seconds and replace it to reset the bios to defaults. I'm not sure if the 8400 has a reset jumper or not.

One of the 8400s I worked on continued to have the fast fan problem even after recapping. I never did figure that one out, though I suspected a damaged thermistor on the board somewhere.

As for the noise...that sounds more like power supply noise than motherboard noise, though I could be wrong. If you do open up the power supply, do so only with it unplugged and after it has been off for several minutes. The primary caps can hold a charge for quite awhile and some of the bits inside may be live with power. I usually pull the power cord out with the computer on to make sure all the power is drained.

[Donal]

Re: Dimension 8400 with bad HN(M)'s

I hate to revive and old topic but I have an 8400 of a customers now with the bad caps. I removed all that were bulging. I am buying them through this site and want to know of these will work:

5 x 1000 uf 10v replacing with these:
https://www.badcaps.net/store/produc...products_id=47

1 x 2200 uf 10v replacing with this:
https://www.badcaps.net/store/produc...products_id=32

1 x 2200 uf 6.3v replacing with this:
https://www.badcaps.net/store/produc...products_id=32

Are there any others I should be aware of? The fan on this thing sounded like a jet plane. Glad I bookmarked this site.

I have an 8400 with the exact same bad caps. I wasn't careful and didn't notice which slot the 2200 uf 6.3v cap came from. Can anybody clue me in?

Thanks,
Don.

[Per Hansson]

Re: Dimension 8400 with bad HN(M)'s

Maybe these threads can help?

https://www.badcaps.net/forum/showth...?t=8750&page=2

https://www.badcaps.net/forum/showthread.php?t=14893

[Donal]

Re: Dimension 8400 with bad HN(M)'s

I had read those and went back and re-read them. Didn't find mention of the location of the 2200uf 6.6v. But, I can make a guess at where it goes.
Thanks,
Don.

[Donal]

Re: Dimension 8400 with bad HN(M)'s

I meant to say "2200 6.3v" .

Thanks,
Don.

[Donal]

Re: Dimension 8400 with bad HN(M)'s

I did find a thread that mentioned where this cap is located. It's in front of left side of the memory slots. Very much appreciated.
Thanks,
Don.