Comments on: IBM AS/400 MODEL 820 Power Supply Failure

By: TomLiotta

TomLiotta — Thu, 30 Aug 2012 17:51:11 +0000

Without knowing the purpose of P03 (nor P02 or maybe P01 after renaming), there is no way to know. I haven't physically worked with 820 hardware. However, since upgrading to redundant power supplies is CSU (Customer Set Up) and MES, I wouldn't be too worried about opening the box and moving power supplies around. If they all are the same type and rating, I'd switch P03 and P02 (or P01 now) and test IPL results. With no expansion unit, I'm not clear at all what P03 is doing there. -- Tom

By: drussel

drussel — Thu, 30 Aug 2012 13:03:50 +0000

Tom, good questions and observations. Yes the supplies are listed as P01, P02 and P03. Since the box will not IPL, I cannot tell you much about the config. There is no expansion tower etc on the system at this time. There may have been at some point prior. Hence that may explain why there are 3. The control panel shows P02 as the failed supply. When I switch it and P01, it then shows P01 as the failed supply. So I feel confident I can identify the failed unit. Is there a way to tell the system to ignore the failed power supply? I have tried IPLing with the failed unit removed.Thanks

By: TomLiotta

TomLiotta — Thu, 30 Aug 2012 06:57:52 +0000

Since there have been no comments, have you learned more about your configuration? Unfortunately, since the failure had already happened, there wasn’t much point in a quick answer from anyone.

The first minor oddity with your question was your reference to “three” power supplies. Redundant power supplies in an 820 are installed in pairs. So, without knowing the distribution of the three that you have, we don’t know if you have three separate power supplies or if P2 was one of a redundant pair.

Also, ‘multiple power supplies’ isn’t the same as ‘redundant power supplies’. To make a pair redundant requires some installation. If it was ordered as a redundant feature, then whoever installed it needs to be brought to task. But if it was just another power supply for, e.g., an expansion rack, then there was probably no redundancy involved.

That brings up a second very minor oddity. You called it “P2″. I would normally expect a second and redundant power supply to get named “P02″. Was that just shorthand?

Tom