Hey all,
I was going through my stack of old boards, and i found an Abit Kt7-RAID.. Just for "old times sake" i decided to do a custom recap job on it..
The caps on the CPU VRM secondary side were replaced with Panasonic FJ's from a scrapped MSI Neo 4 platinum, with a 330uF Sanyo Oscon added for noise cleanup. The CPU VRM primary caps, chipset/RAM VRM secondary side were all replaced with Nichicon PW, appropriately sized with larger diameter caps for longer life.. 7K hours plus...
Now for the interesting part, the chipset/RAM primary side. Originally it had a set of 4 16V 1000uF Jackons in it.. I had replaced the set of 4 with a single 3300uF 6.3V Nichicon PW, and a 330uF 6.3V Sanyo Oscon. I had no idea that the 16V voltage rating was actually needed. ;-) Turns out the KT7 actually uses +12V from the ATX connector to power the RAM and chipset.. I had intended to check the noise at the VRM input, and i kept seeing +12VDC there.. I had assumed that like pretty much all other older Socket A boards that the VRM would be fed off +5V.
So that 3300uF Nichicon PW and 330uF Oscon got the benefit ;-P of having +12V applied to a pair of 6.3V rated caps, and neither one vented or showed any sign of distress after over 24 hours of Prime95 burnin.. The board was perfectly stable either stock or overclocked, though i forget what type of FSB the old KT133 chipset would top out at..
Of course i'm going to be unsoldering them and replace them with 16V rated parts, but the fact that they seem to have survived having double their rated voltage applied for >24 hours is encouraging..
So the lesson today is that if you see 16V or higher rated caps on a board, it's probably a good idea to check the voltages actually present there. Don't just assume that because the board lacks the ATX 12V connector that none of the onboard VRMs might have +12V at its input..
This should also serve as a warning to those that still may have Abit KT7-X boards that having the RAM/chipset VRM short would result in +12V being applied to your RAM and chipset.. I think you would see more than just burnt labels on your RAM in that case.. :-P
I was going through my stack of old boards, and i found an Abit Kt7-RAID.. Just for "old times sake" i decided to do a custom recap job on it..
The caps on the CPU VRM secondary side were replaced with Panasonic FJ's from a scrapped MSI Neo 4 platinum, with a 330uF Sanyo Oscon added for noise cleanup. The CPU VRM primary caps, chipset/RAM VRM secondary side were all replaced with Nichicon PW, appropriately sized with larger diameter caps for longer life.. 7K hours plus...
Now for the interesting part, the chipset/RAM primary side. Originally it had a set of 4 16V 1000uF Jackons in it.. I had replaced the set of 4 with a single 3300uF 6.3V Nichicon PW, and a 330uF 6.3V Sanyo Oscon. I had no idea that the 16V voltage rating was actually needed. ;-) Turns out the KT7 actually uses +12V from the ATX connector to power the RAM and chipset.. I had intended to check the noise at the VRM input, and i kept seeing +12VDC there.. I had assumed that like pretty much all other older Socket A boards that the VRM would be fed off +5V.
So that 3300uF Nichicon PW and 330uF Oscon got the benefit ;-P of having +12V applied to a pair of 6.3V rated caps, and neither one vented or showed any sign of distress after over 24 hours of Prime95 burnin.. The board was perfectly stable either stock or overclocked, though i forget what type of FSB the old KT133 chipset would top out at..
Of course i'm going to be unsoldering them and replace them with 16V rated parts, but the fact that they seem to have survived having double their rated voltage applied for >24 hours is encouraging..
So the lesson today is that if you see 16V or higher rated caps on a board, it's probably a good idea to check the voltages actually present there. Don't just assume that because the board lacks the ATX 12V connector that none of the onboard VRMs might have +12V at its input..
This should also serve as a warning to those that still may have Abit KT7-X boards that having the RAM/chipset VRM short would result in +12V being applied to your RAM and chipset.. I think you would see more than just burnt labels on your RAM in that case.. :-P
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