When I first built this box, it was pretty quick. I used it a bit, then put it away for a few months. I just recently got it out again and it just kept getting slower and slower. I took the board out and sure enough it had KZGs in the VRM. Replaced those, put it back together, still crappy.
I decided to recap the whole board. It was using Panny FJ 820uv 6.3v, about 20 of them, and 4 Lelon 100uf 16v.
Between Ruby ZLs and Sanyo WGs I had enough 1000uf 6.3v to do the job, and I had Nichicon PW to replace the Lelons. I really didn't think the board was going to go again so I wasn't too sad to use the ZL's which are 10mm to replace the 8mm FJs around the PCI slots.
So I power it up. First difference is the POST speaker was really loud.
No more gutlessness. I put a SCSI card and drive in, which I consider a
great way to test the condition of a board. A gutless board will have trouble handling SCSI.
So what was causing the gutlessness? The Panny FJs all had ESR of .27 or higher. They were also slow to respond to the ESR meter. Their capacitance was uniformly 750 uf.
The KZGs were all pretty good. Typical ESR about .08.
The new ZLs and WGs had ESR of .04 or better and responded to the meter
with rapidly falling ESR values.
I hate those dinky little 8x11 electrolytics. They just dry out too fast.
I decided to recap the whole board. It was using Panny FJ 820uv 6.3v, about 20 of them, and 4 Lelon 100uf 16v.
Between Ruby ZLs and Sanyo WGs I had enough 1000uf 6.3v to do the job, and I had Nichicon PW to replace the Lelons. I really didn't think the board was going to go again so I wasn't too sad to use the ZL's which are 10mm to replace the 8mm FJs around the PCI slots.
So I power it up. First difference is the POST speaker was really loud.
No more gutlessness. I put a SCSI card and drive in, which I consider a
great way to test the condition of a board. A gutless board will have trouble handling SCSI.
So what was causing the gutlessness? The Panny FJs all had ESR of .27 or higher. They were also slow to respond to the ESR meter. Their capacitance was uniformly 750 uf.
The KZGs were all pretty good. Typical ESR about .08.
The new ZLs and WGs had ESR of .04 or better and responded to the meter
with rapidly falling ESR values.
I hate those dinky little 8x11 electrolytics. They just dry out too fast.
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