RH1448Y - trying to fix server PSU, C&D Technologies/Murata Power Solutions - Page 1
Forum section: electronics / projects

author: arekm
author_rank: Unknown
timestamp: February 02, 2014, 09:33:44 pm
content: Hi.I'm trying to run HP RH1448Y server PSU (12V, 138A, 1.6kW) outside of the server.PSU contains two internal fans. First fan (the one in middle) starts immediately. Second fan is supposedto start when PSU is signalled to start providing 12V output. Both fans are not damaged and working finefrom external 12V and also working when swapped.Now the fun part:- if fan2 (the one from the edge) is connected then output 12V drops to 3-4V and fan2 doesn't start- if fan2 is disconnected then output 12V is stable (was drawing ~50W from output without a problem)- if fan2 is disconnected then PSU reports fan failure through I2C interface (but 12V is stable)- if I reconnect fan2 then 12V drops to 3-4V and I2C reports "Primary Overtemperature" or "Secondary Overtemperature" (sometimes primary, sometimes secondary) which is obviously not true since everything is cold (didn't get a change to overhead, too short period)- NTC (for secondary) and diode (for primary) are used to measure temperature and look to be fineSo the question is - what could be wrong with fan2 driver causing such errors/problem? Not even sure what exactly drives it. PCB tracks hide under heatsink near output connector (and dismanting it is going to be really hard).I don't see any part being damaged, capacitors look fine, no obvious shorts on capacitors.Maybe someone worked with such type of PSU and had similar problem... unlikely but well.Note, this PSU was made by C&D Technologies which is Murata now. Unfortunately Murata supportdidn't even bother to answer.ps. on some photos one heatsink was desoldered to see what is under

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 03, 2014, 01:45:31 am
content: What happens if the first fan is disconnected but the second fan is connected?

author: arekm
author_rank: Unknown
timestamp: February 03, 2014, 05:09:28 am
content: In such case the output also goes down from 12V to 3-4V and PSU reports fan1 failure and overtemperature condition.If I disconnect both fans then PSU reports fan failures, general failure but provides stable 12V.

author: Knightmare80
author_rank: Newbie
timestamp: April 12, 2014, 07:09:53 am
content: Hello,maybe you can Help me.1. You found our error?2. I want to build a Mining Rig and Buy some of this RH1448Y from a Friend.My Question are, how to Start the PSU and maybe you know about the Terminal 12V and 3,3V Output?Thanks for Help.regards,Karsten from germany

author: arekm
author_rank: Unknown
timestamp: April 12, 2014, 07:23:37 am
content: Wasn't able to fix the issue (and Murata company is useles - they don't even answer).Readhttp://www.murata-ps.com/data/acdcsupplies/cps_d1u4-w-1600-hx.pdffor all information.

author: robots
author_rank: Contributor
timestamp: May 15, 2014, 07:33:01 am
content: Where did you find specification for the i2c ? I have HP DL580 psu, and i am interested what information can i get from it.

author: arekm
author_rank: Unknown
timestamp: May 15, 2014, 07:44:27 am
content: www.murata-ps.com/data/apnotes/acan-31.pdf

author: qbeusz
author_rank: Newbie
timestamp: November 24, 2014, 11:31:46 pm
content: Hi,Can anyone tell me, how to power up this PSU?I have information about "Main Output Absent", and on +12V pinouts, I have 0V.Thank you

author: snickers
author_rank: Contributor
timestamp: April 07, 2024, 11:44:04 pm
content: To start PSU you need to down PS_ON only after AC_OK rised.