Recapping caused 64k base failure?

[ZuluLima]

I had an old Intel D865GlCL that WAS booting with leaking VRM input. So I recaped the entire thing with four 16v 1800uf MCZ's (four 16v 1500uf HD used to be there) for input. Ten 2.5v 820uf SEPEC for output (three 6.5v 820uf MCZ and seven 2.5v 680uf Chemi-con polymers were there). Then a new 6.5v 820uf MCZ for the ram. There was also a 10v 2200uf HM with a coil beside it near the south replaced by a MCZ the same size. Everything soldered in without a single scratch. Now I get three beeps at power on (64k base failure). Everything is getting the correct amount of power, and gets to normal temp by touching them. Ram and cpu are good. Would modding the vrm solid do this or changing the MBZ to MCZ in the ram do this? I don't know.

[ZuluLima]

Re: Recapping caused 64k base failure?

Also the led light on the board now goes out in 3 sec. rather than 6 sec. after I hit the psu power switch.
Too low of esr from the Rubycons?? Can't be.

[seanc]

Re: Recapping caused 64k base failure?

Tried resetting the CMOS?

[ZuluLima]

Re: Recapping caused 64k base failure?

3 times.

[seanc]

Re: Recapping caused 64k base failure?

If you post pictures of your work, someone may be able to indentify why the caps you have chosen are not correct for that section of the board.

[PCBONEZ]

Re: Recapping caused 64k base failure?

Many Intel made boards [at least socket 370 thru 775] used 85C rated 4 and 5 mm caps [usually Nichicon VR] that tend to start showing up as dried out and bad after about 5 years use. Some times they even bloat though hard to see on small caps.
- Might go bad sooner in a hot case or last longer in a well cooled case.
-
A bad one of those could be hosing your CMOS. [So to speak.]
Can also muck-up RAM or CPU communication with the chipset.
.
https://www.badcaps.net/forum/showpo...0&postcount=42
.

[shovenose]

Re: Recapping caused 64k base failure?

why did you replace the polymers?

[ZuluLima]

Re: Recapping caused 64k base failure?

I wanted to replace the three wet MCZ's with polymer. But I can't just throw any 2.5 volt ones in due to very low esr and they will be fighting since they're in paralell. All the three MCZ's did was hold extra charge so the vrm input could keep up with the polys and to save a penny. So increase the uf in each input cap by 200 since each is in series. and increase the uf in the output to 1000. Good on the mosfets.

[c_hegge]

Re: Recapping caused 64k base failure?

EDIT: Oops, misread the previous post. Feel free to delete this one.

[PCBONEZ]

Re: Recapping caused 64k base failure?

Have you checked for any caps in backwards?

I know you said the RAM is good, but you have a RAM error.
See if you can get to the BIOS using one stick, and then swap sticks and try again.
- No joy?
- Look for issues in +5vsb, +5v, and +3.3v [all of which can power RAM depending on the board design and it's 'state'.]
- Look at those small caps I mentioned.
- Look for problems with MOSFETs or LDOs anywhere near the RAM or chipset chips.
- Look for signs of melting or discoloration on the chipset.

If you need this up and running SOON there were two BIN type auctions on eBay for under $30 shipped at the time I posted this.
.

[ZuluLima]

Re: Recapping caused 64k base failure?

I'm going to try to reseat the dimm cap and see what that does. Maybe I didn't get enough solder down the trace.

[ZuluLima]

Re: Recapping caused 64k base failure?

It boots! Incomplete joint.

[PCBONEZ]

Re: Recapping caused 64k base failure?

Congrats!