Problem recapping not one but TWO Soyos

[roazena]

Noob here. A friend's homebuilt Soyo blew and I tried buying a replacement mobo on eBay.

The original board is a K7VME and the new one is a K7VXA (Dragon Plus). The new board arrived and it too had bad caps. No POST.

I took down the specs of all the bad caps on both boards and ordered Panasonic replacements from STSI. After learning the hard way that most soldering irons are worthless for this tast, I finally got a Weller 30W/130W iron this morning and set about removing the old ones and replacing them -- being careful to note negative and positive, using a rubber bulb and dental pick to clean holes. Radio Shack standard rosin-core 60/40 .032" diameter solder.

Neither board POSTs or beeps. With the new board, I noticed too late that there was a broken trace on the backside from one of the power connector's terminals, but the power LED on the board still lights when power's on so I'm not sure what that trace was supposed to power.

I was *trying* to save my friend money by doing this myself, and between us we've already spent $200 on boards, RAM, and electronics supplies.

Not to mention the roughly seven hours I've sat at this table since this morning.

Help.

[kc8adu]

Re: Problem recapping not one but TWO Soyos

post pics of the damaged trace.
i just did 7 kt600 dragon plus for a customer and they all made it.
nasty mess of exploded ost in clear jackets.

[roazena]

Re: Problem recapping not one but TWO Soyos

Here's the picture from the Dragon Plus. Please ignore my feeble attempt to solder it back down to the board.

I suppose there's a chance that both boards' CPUs were (separately) fried and this is why nothing's POSTing.

[roazena]

Re: Problem recapping not one but TWO Soyos

I'll post a pic of the other board after my camera's batteries are done recharging --they were so low the autofocus refused to work.

[roazena]

Re: Problem recapping not one but TWO Soyos

This is the K7VME.

[kc8adu]

Re: Problem recapping not one but TWO Soyos

looks like a shorted card in pci 1 did that.
just solder jumpers and test again.

[roazena]

Re: Problem recapping not one but TWO Soyos

So it's safe to solder a jumper to the tiny thin strip of copper (I assume you're referring to the Dragon Plus pic). Would that actually be responsible for the board not POSTing?

[roazena]

Re: Problem recapping not one but TWO Soyos

looks like a shorted card in pci 1 did that.
just solder jumpers and test again.

I don't get why the K7VME isn't working. How can I tell if I ruined something?

[davmax]

Re: Problem recapping not one but TWO Soyos

There are a number of possibilities other than a fault.

1. Make sure all caps are inserted with the correct polarity.
2. Clean up your soldering. One pic shows what looks like fine steaks of solder splattered on board. First get some methylated spirit and an old tooth brush (stiff bristles) and clean off all solder flux (looks horribly black, hope you used good quality solder) and dry it off. Then with a magnifying glass check for fine a minute solder pieces that may be causing a problem. Take a close look at your soldering and make sure the connections are good.
3. The CMOS(bios) may be corrupted. Look for the reset jumper (three pins oftem labelled CMOS or Jbat) move the jumper to the alternate position leave for 15 sec and then move it back to the default position. If you can access a manual check that this jumper is in the default position before you power on.

[roazena]

Re: Problem recapping not one but TWO Soyos

There are a number of possibilities other than a fault.

1. Make sure all caps are inserted with the correct polarity.

They were. The board appears to be standard on "white half-circle = negative."

2. Clean up your soldering. One pic shows what looks like fine steaks of solder splattered on board. First get some methylated spirit and an old tooth brush (stiff bristles) and clean off all solder flux (looks horribly black, hope you used good quality solder) and dry it off. Then with a magnifying glass check for fine a minute solder pieces that may be causing a problem. Take a close look at your soldering and make sure the connections are good.

No idea how to tell if 60/40 rosin core solder is good or not. I will get methylated spirits tomorrow and clean the black stuff off.

3. The CMOS(bios) may be corrupted. Look for the reset jumper (three pins oftem labelled CMOS or Jbat) move the jumper to the alternate position leave for 15 sec and then move it back to the default position. If you can access a manual check that this jumper is in the default position before you power on.

This has been done with both boards, with the power supply unplugged (as per the Dragon Plus PDF manual).

Thanks for the advice and I'll report tomorrow on all of this.

[Fizzycapola]

Re: Problem recapping not one but TWO Soyos

That soldering doesn't look too cool. After soldering what you see shouldn't look any different from the factory soldering.

[PCBONEZ]

Re: Problem recapping not one but TWO Soyos

Check The Power Supply!!

[RJARRRPCGP]

Re: Problem recapping not one but TWO Soyos

Neither board POSTs or beeps.

The processor may have been damaged.
I hope you were careful when you reclipped the heatsink.
Is it socket A or slot A?

Socket A is the most likely to have crunched cores.