HP 742C with 10 bad caps

[rudeguy]

Hello all. I have an HP 742c desktop that has 10 bad caps. I have never replaced caps, but am OK with soldering. My question is which caps should I get? The caps are all 1500u 6.3V with 105c temp.

Link to mobo

The caps are all the same. [/IMG]

Sorry its so blurry.

[kc8adu]

Re: HP 742C with 10 bad caps

imperial gl/gv ve?
i use 820@2.5 polys in those.
just the ones on vcore though.
these were a common trouble board so i bet topcat has a kit for these.the kit is the easy way if this is the only board you intend to fix.

[rudeguy]

Re: HP 742C with 10 bad caps

imperial gl/gv ve?
i use 820@2.5 polys in those.
just the ones on vcore though.
these were a common trouble board so i bet topcat has a kit for these.the kit is the easy way if this is the only board you intend to fix.

What's topcat and how do I order the kit?

[Scenic]

Re: HP 742C with 10 bad caps

topcat is the owner of this site

http://badcaps.net

[rudeguy]

Re: HP 742C with 10 bad caps

topcat is the owner of this site

http://badcaps.net

Oh right. Good job topcat!

I was hoping someone could link me to what I need to order. I have searched all over trying to find the right caps and all I can figure out is that the are 1500u, 6.3v.

I am a noob to this kind of thing, any help would be appreciated.

[TahoeEd]

Re: HP 742C with 10 bad caps

I've done several boards, so I'm by no means an expert compared to many folks around here.

Here's a few tidbits of advice:
If you don't have a desoldering tool, this is the best $11 you'll ever spend:
http://www.radioshack.com/product/in...ductId=2062731

You might as well replace everything on the board that has a vent on it, not just those that are leaking. You'll have it torn all apart.

If you don't want to order from Topcat (and there's no reason not to, I've swapped a few emails with him, this is a great site), you can order some from Mouser. I've bookmarked this page to help select different series from different manuf's:
https://www.badcaps.net/forum/showthread.php?t=2280

Mouser carries lots of Nichicons, look at the Nichicon HZ or HN. From your picture, it looks like those are 8mm in diameter. To search Mouser, select these items:
Mouser.com -> Product Finder -> Passive Components (homepage)
Capacitors -> Aluminum Electrolytic Capacitors
Termination Style : Radial
Product: Low Impedence Electrolytic Capacitors
Select "Apply"
Now pick your next factors:
Capacitance: 1500 uF
Voltage: 6.3V (control-click to also pick 10V, 10V will work fine)

It looks like those are 8mm diameter caps, but there looks to be space for 10mm diameter caps. I've got a cheap caliper that is really handy:
http://www.harborfreight.com/cpi/cta...temnumber=7914
http://www.harborfreight.com/cpi/cta...emnumber=47257
I actually use the $2 one all the time.

Also measure your lead spacing if you want an easy job. I believe 3.5mm is standard for 8mm diameter caps, and 5mm for 10mm diameter caps.

Look at specific details from the Nichicon site:
http://www.nichicon-us.com/english/p...ini/list_f.htm
(Click on "Diagram Search" to see the relationships between different series).

Looking at what's in stock...
Here's an 8mm in the HN:
http://mouser.com/Search/ProductDeta...%2fcJQaQ%3d%3d

Here's the 10mm in the HZ:
http://mouser.com/Search/ProductDeta...S2wHteKg%3d%3d

From one beginner to another....best of luck!

[kc8adu]

Re: HP 742C with 10 bad caps

hn are a possible problem series.
at any rate they dont take heat very well.
these are all on vcore on imperial mobo's.
fill any empty spots when you recap.
btw i recapped this with nippon chemi con psa 820@2.5v
the very common fujitsu re 820@2.5 are the same.
i have both on hand in large quantity so i use them wherever i can.
see pic

[PCBONEZ]

Re: HP 742C with 10 bad caps

Mouser stock for HN and HM is new/current production.
Not the old 2001-2004 vintage with problems.
-
Using poly in Vcore as kc8adu suggested is a probably a good idea anyway.
Not mandatory, just a good idea....
Poly's do better than Lytics right next to a hot CPU.
-
Get a 60+ watt soldering iron. Mobo PCB is thick and you'll be glad you did.
(Well, no, you won't. You won't know how much it sux to use a smaller one if you're using a 60+watt to start with.)

Also if you have a Bestec 250 watt PSU (often found in Imperial GL/GV based systems) then chunk it in the shit-can and get one that doesn't burn-out chipsets on motherboards.
.

[rudeguy]

Re: HP 742C with 10 bad caps

Once again, I am a simpleton about this kind of stuff. Could someone please link me to a specific page and tell me exactly which caps to order? I understand that I will need a 60+ watt iron, a scraper and a sucker. The caps are what I am unsure of.

[PCBONEZ]

Re: HP 742C with 10 bad caps

You aren't simpleton. You're a newbie. There is a difference.
Welcome Newbie! -

All the caps you are replacing are 1500u 6.3v?
What make and series?
What diameter are they?
You going Lytic or Poly?
-
Make sure specs on new ones meet or beat specs on old ones.
You want ESR on the new caps to be the same or less.
You want Ripple to be the same or more.
Make sure diameter will fit in the spot.
Next to slots or CPU make sure height isn't an issue.
8mm usually has 3.5mm lead spacing.
10mm and 12.5mm is usually 5mm lead space.
For a Mobo 6.3v and 10v caps are interchangeable as on a motherboard they are used on 3.3v or 5v power and either 6.3 or 10 caps will do fine.

As for grade:
HM is comparable to MBZ.
HN is comparable to MCZ.

To order from here go to:
https://www.badcaps.net/pages.php?vid=23

You can also go to eBay, Mouser, or Digikey if you are in the US.
-
In this case Digikey is probably only good for poly.
The highest grade of Lytics they stock is Panasonic FM which is slightly less than MBZ.
(Not much less though.)
.

[Scenic]

Re: HP 742C with 10 bad caps

another option (if you have paypal)

http://tinyurl.com/pcmcstore

just avoid audio caps or OSTs