Asus A7V333-X - missing component

[LeGrr]

Hello everybody,

I got one Asus A7V333-X mobo few weeks ago. It is jumperless motherboard. With Duron 750 everything runs well. If I put cpu XP2000 or Athlon1200 (working ones ), the motherbord never post. When I take a closer look I discovered that one component on the bottom side is missing. It looks like smd capacitor to me. Is it "safe" just to put another one which looks like the rest of the group?

Also, one chip (ICS UJ260625) placed next to atx connector is really warm. I have another mobo (Asus A7V8X) with same chip, which is a lot cooler.

All "big" caps are rubycon yxg, few little ones (10 uF) are g-luxon (placed next to lan chip). One of capacitors (CE17, 2200-6.3V) looks different than others, its rubber bottom looks about 1-2 mm lower.

I tried few good power supplies with the same results.

Thank You

[gonzo0815]

Re: Asus A7V333-X - missing component

The ICS chips is the pll synthesizer, for which it is normal running hot.

For the MLCC cap take a X7R one and take the largest value which fits.
Probably it is a value in the range of 1uF to 4,7uF.
Values up to 1uF are easily available, the higher ones are not.

[LeGrr]

Re: Asus A7V333-X - missing component

Thank you, Gonzo, I will try to find cap with largest value
Is it possible to expect that mobo will post with faster cpu when I put that missing cap, or the problem with post is somewhere else?

Is it normal to put small radiator on that ICS chip, because it reaches about 70 (C) degrees? This chip is twice hotter than any other ICS chip I ever touched

[999999999]

Re: Asus A7V333-X - missing component

I have a spare A7V333 which I just looked at hoping it was similar but there are enough differences it isn't as helpful as I'd have liked. It has no caps at all behind the CPU socket and a different trace/plane layout.

Since your board runs the Duron without that cap, it's doubtful it is what is preventing use with the other processors. With the Duron in, you might try updating the board to the newest bios, then clearing CMOS with AC power disconnected, THEN trying the other CPUs.

The Duron has a lower FSB speed and thus lower memory speed too by default. I suspect this is the primary problem, I vaguely recall A7V333 boards were fairly picky about memory especially at 133MHz or higher memory clock rate. If you have more than one memory module installed, try removing all but the smallest one and putting it in the slot closest CPU or closest ATX connector, not the middle slot. Leave middle slot empty if/when possible.

It's been a while since I modded my A7V333 but apparently mine had hot running PLLIC chips too as I have heatsunk mine. It might be something to consider IF you ever getting it running with the faster CPus, but when you turn on the system from cold/off and it won't start this cannot be the problem because the PLLIC isn't hot (overheated) yet. IOW, no point in spending time on it yet if the board isn't viable for your use.


It's a shame your board is jumperless, mine has more jumpers than most boards of that era and can have vcore and FSB speed changes, maybe even memory sync/async mode changed. If you could jumper the board down to the 100MHz FSB speed the duron uses, that would help isolate whether the board has a problem with the other processors or the higher bus speed they default to... but be sure to clear CMOS after the CPU change.

These boards use a lot of 5V current, are you certain your good PSU have a lot of 5V current capability? Most current generation PSU do not, the target for that board would be a PSU with combined 3V+5V rating of at least 180W but closer to 200-230W would be better if a power hungry video card or a lot of other cards and memory are installed.

I could be wrong, maybe that missing capacitor matters but I doubt it, at least not just to get the board to start posting opposed to running stable later. Regardless, as gonzo stated it is not going to be a value-critical part just put what you have on there as it's not going to be a capacitance-sensitive circuit especially when it already runs without it at all. You could even cannibalize a cap off something else you have though it is easily to overheat and damage a ceramic cap if you don't have a controlled hot air station or hot tweezers, it is much riskier to remove one with just a soldering iron but maybe easier to do it that way if you drape a piece of desoldering braid over the cap and squirt some flux onto it so the whole thing lifts up at once.

[999999999]

Re: Asus A7V333-X - missing component

I have a spare A7V333 which I just looked at hoping it was similar but there are enough differences it isn't as helpful as I'd have liked. It has no caps at all behind the CPU socket and a different trace/plane layout.

For some reason I had thought that picture and cap were behind the CPU socket. I now realize it was behind the chipset and my non-X version does have caps there but still it does not have them in the same locations due to a different trace layout.