Biostar M7VKD recapping

[BlakeW]

Hi all,
I identified this board as having bad caps... i've replaced the high value ones with some other similar value capacitors (note that i have no idea what brand they are, the only noticable markings are "7123MB" and "W"), however the board doesn't even get to POST. no beeps either.

I'm wondering how i should trouble shoot this. should i check the voltages at the regulators and check for proper continuity?

[kc8adu]

Re: Biostar M7VKD recapping

always post pics.
look under manage attachments when you post.
btw did this board post before the recap?

[BlakeW]

Re: Biostar M7VKD recapping

I completely neglected to test the board before i went for the replacement, as the caps looked so awful that i didn't trust it.

attached is the only in-focus pic of the old caps i could find.

[zandrax]

Re: Biostar M7VKD recapping

Welcome Blake: those G-Luxon were obviously bulged, some even started to leak. You recapped the whole vrm and motherboard still doesn't post: it doesn't even start or it power on and switch off an instant later?
In first case chances are regulators are damaged: there is a step by step vrm checking guide in Badcaps forum, but I can't find it. Damn ...
In second one something prevents the boot: there are a lot of plausible reassn, such as bulging/shorted minor caps, corrupted cmos or some ICs burned.

Zandrax

[i4004]

Re: Biostar M7VKD recapping

testing
https://www.badcaps.net/forum/showth...ht=testing+vrm

[BlakeW]

Re: Biostar M7VKD recapping

Ok, for some reason the computer now gets to POST, but it's saying "BIOS ROM checksum error"... and is only accepting floppy boot disks. i've tried flashing the rom with the official rom file and flash program, but still no luck. also, it doesn't like more than one ram stick in at a time... should i replace the 1000uf G-Luxons also? [/stupid question]

[BlakeW]

Re: Biostar M7VKD recapping

ah sorry about that, turned out to be incorrect fsb and ratio settings... i'm in the bios now, will check the voltage levels.

got a vcore of 1.65V, +3.3V rail is at 3.20, +5V is at 5.05, and +12 is at 12.30.