Tyan Trinity KT S2390 - VRMs? Capacitors?
A friend of mine was going to toss out a Tyan Trinity KT S2390 board. It stopped booting up one day, and he later ended up buying a new motherboard and CPU. The computer store told him that his CPU had gone bad and they said it was likely that the board fried the CPU since the heatsink and fan were all properly installed.
I should say that I've successfully recapped 3 mainboards so far (with Rubycon MBZ's) - two Abit KT7A's and a Soyo 7VEM, which all seem to be working better than they did when brand new.
I've looked at this Tyan board, and none of the capacitors seem *visibly* bad. None of the capacitors are bulging, none are vented, none seem to be leaking beneath the capacitors either.
The biggest capacitors are 1500uf 10V, with a brand I cannot identify... the only branding on these caps seems to be the letters "LE" contained within a rectangle. The board is then littered with a bunch of Canicon caps - 1000uf 6.3V. The rest are 470uf Rubycons and other smaller value caps.
I'm really hesitant to put a good working CPU and RAM in this board to "test" it, if there is a good chance that the board could fry it. I'm also hesitant to spend the time replacing ALL the capacitors on the board, only to find out that the caps aren't the problem.
I powered up the board without any CPU and RAM installed. Of course, no beeps or anything, but it powers up.
The board has 6 VRMs near the CPU, sort of scattered about. I used a digital multimeter to check the voltages at both sides of the VRMs to ground. Out of the 6 FETs, I was able to measure 5 volts on one side only of two FETs. The other side read 0V, and the other 4 VRMs read 0V on both legs.
If no CPU or RAM is installed, should I expect to read no voltage on both sides of 4 of these VRMs?
Of the two VRMs that read 5V on 1 side, would I at least expect to read, for example, 3.3V or some other voltage on the other side?
Would capacitors that are leaky or otherwise faulty, cause the VRMs to not function at all?
Would it make sense as an initial diagnostic, to replace the capacitors near the CPU and then try testing the VRMs again?
Would it make sense to try replacing all 6 of the VRMs wholesale and test again? I am not familiar with VRM circuitry, so I don't have a clue if these VRMs are all supposed to be fed with 5V, or 3.3V or 12V or if they are cascaded or what.
I also tried checking the impedance between each side of the VRM and various ATX power supply pins (5V, 12V, etc). It was inconclusive because the impedance seemed to increase as if a capacitor were being charged up.
I should say that I've successfully recapped 3 mainboards so far (with Rubycon MBZ's) - two Abit KT7A's and a Soyo 7VEM, which all seem to be working better than they did when brand new.
I've looked at this Tyan board, and none of the capacitors seem *visibly* bad. None of the capacitors are bulging, none are vented, none seem to be leaking beneath the capacitors either.
The biggest capacitors are 1500uf 10V, with a brand I cannot identify... the only branding on these caps seems to be the letters "LE" contained within a rectangle. The board is then littered with a bunch of Canicon caps - 1000uf 6.3V. The rest are 470uf Rubycons and other smaller value caps.
I'm really hesitant to put a good working CPU and RAM in this board to "test" it, if there is a good chance that the board could fry it. I'm also hesitant to spend the time replacing ALL the capacitors on the board, only to find out that the caps aren't the problem.
I powered up the board without any CPU and RAM installed. Of course, no beeps or anything, but it powers up.
The board has 6 VRMs near the CPU, sort of scattered about. I used a digital multimeter to check the voltages at both sides of the VRMs to ground. Out of the 6 FETs, I was able to measure 5 volts on one side only of two FETs. The other side read 0V, and the other 4 VRMs read 0V on both legs.
If no CPU or RAM is installed, should I expect to read no voltage on both sides of 4 of these VRMs?
Of the two VRMs that read 5V on 1 side, would I at least expect to read, for example, 3.3V or some other voltage on the other side?
Would capacitors that are leaky or otherwise faulty, cause the VRMs to not function at all?
Would it make sense as an initial diagnostic, to replace the capacitors near the CPU and then try testing the VRMs again?
Would it make sense to try replacing all 6 of the VRMs wholesale and test again? I am not familiar with VRM circuitry, so I don't have a clue if these VRMs are all supposed to be fed with 5V, or 3.3V or 12V or if they are cascaded or what.
I also tried checking the impedance between each side of the VRM and various ATX power supply pins (5V, 12V, etc). It was inconclusive because the impedance seemed to increase as if a capacitor were being charged up.
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