Acer Aspire V76M

[LENOVO-A880]

Hey all,
I'm very new to electronic fine soldering (or soldering capacitors at all). I have an used motherboard which I want to start an interesting (and in fact, for fixing, testing, trialing and improving purposes) project on it. However, I really don't know if these are bad, it's just that all of the green colored one on this motherboard which is from year 1999 are slightly bulged out on their top except for 1 or 2 which is visible in the both photos. What happened was a couple months ago, I tried to turn ON this failing motherboard and it did turn ON for a few moments then hangs in Windows. Again after a few try, the PC won't turn on (black screen) and no light blinking for the LED too. I tried several attempts to turn it on (case opened) with only a few components attached like "RAM", "CPU", "Ethernet Card" by shorting the 2 pins on the header of the motherboard together is exactly what the power button on the front panel does. Then still it won't power up and not even hearing a single beep from it.

Questions:

1. I would be real keen to try replacing the caps if someone else can tell me if these caps are really bad or they are supposed to look this way, there is no leakages at all but a faint smell comes from the board but it could just be my imagination... It's a Acer Aspire V76M motherboard....What do you suggest?
2. I guess my real question is, are there any 'Good' caps that have slight bulges, it is weird that those green ones have no leakage but the motherboard won't power up at all....

[lexwalker]

Re: Acer Aspire V76M

Hey all,
I'm very new to electronic fine soldering (or soldering capacitors at all). I have an used motherboard which I want to start an interesting (and in fact, for fixing, testing, trialing and improving purposes) project on it. However, I really don't know if these are bad, it's just that all of the green colored one on this motherboard which is from year 1999 are slightly bulged out on their top except for 1 or 2 which is visible in the both photos. What happened was a couple months ago, I tried to turn ON this failing motherboard and it did turn ON for a few moments then hangs in Windows. Again after a few try, the PC won't turn on (black screen) and no light blinking for the LED too. I tried several attempts to turn it on (case opened) with only a few components attached like "RAM", "CPU", "Ethernet Card" by shorting the 2 pins on the header of the motherboard together is exactly what the power button on the front panel does. Then still it won't power up and not even hearing a single beep from it.

That is quite a pretty ancient mainboard, with SiS620 chipset. As for the problems described, before diving into mainboard repairs, have you tried any of these troubleshooting steps below...

- Use a different PSU. Sometimes a bad/failing PSU can cause such symptoms.
- Clean the contacts in the DIMM slot. Can use contact cleaner.
- Check for dried thermal paste on the processor. Clean off the old thermal paste and apply a new layer of thermal paste.
- Using one piece of SDRAM stick only. Swap the memory sticks around to test for any faulty ones. Also try different memory slots.

Questions:

1. I would be real keen to try replacing the caps if someone else can tell me if these caps are really bad or they are supposed to look this way, there is no leakages at all but a faint smell comes from the board but it could just be my imagination... It's a Acer Aspire V76M motherboard....What do you suggest?
2. I guess my real question is, are there any 'Good' caps that have slight bulges, it is weird that those green ones have no leakage but the motherboard won't power up at all....

Well, first off....

- Sometimes badcaps do not bulge nor show any signs at all. The only proper way to check is to remove the capacitor off the board and test it with a capacitance meter and/or ESR meter.
- You may have to check the actual Vcore of the processor at the MOSFET pins. The smell could be an overheating MOSFET as well...
- Dry or cracked solder joints is another thing to look into, especially in areas such as the processor socket pins (under the board)...
- Since its quite an old motherboard, sometimes there could be other failing components (including the main chipset itself). This one is hard to determine until all main suspects (such as those capacitors) are dealt with...