Cooler Master V850 Troubleshooting Repair - Page 1
Forum section: electronics / repair

author: noto64
author_rank: Newbie
timestamp: August 29, 2025, 03:13:17 pm
content: Hi guys, My first post.So I purchased an old intel i3 2100 system with a CM V850 power supply. It worked without any issues on the intel system, but when I tried to use it on my amd 5600g system it will turn on for half a second and then shutdown. It won't power on after that for hours. Manually shorting to power on the psu works fine and all voltages are within specs and all. Tried it on another am4 system a and another intel i5 6600 system. It worked on Intel system will shutdown after 1/5 second on the am4.I gave it for repair to a technician. He can repair it but has no idea what's wrong with the power supply. And he especially repairs power supplies and motherboards.So I'm am asking what could be the issue? OPP or OVP or OCC circuit tripping.Forgot to mention that when I tried it on my 5600g system the motherboard died, but that motherboard died before too with another psu and after rma it died again. So I don't know if that has anything to do with the V850 or not.Thank You.

author: Swake
author_rank: Frequent Contributor
timestamp: August 29, 2025, 07:15:47 pm
content: Let me recap: You have a Cooler Master V850 power supply that works in 2 Intel systems but does not work in 2 AMD systems.What makes you think the power supply is having a problem? Are those 2 AMD systems working with another power supply?

author: noto64
author_rank: Newbie
timestamp: August 29, 2025, 08:55:21 pm
content: Quote from: Swake on August 29, 2025, 07:15:47 pmWell, one of those am4 systems with MSI B450 Mortar Max works perfectly fine with another older cooler master psu and my newly purchased cx550. The Asrock B450M HDV R4.0 motherboard in the other am4 system has died on me 3 times now, 1st time only after 2 months with the cx550, 2nd and 3rd time after I tried it with the V850. So maybe the asrock board I had, and had received after the rma were all faulty, which would be astronomically impossible. TO NOTE: that I was using the Asrock board with a 5600g with missing Vss and Memory pin.The intel system I tested on were relatively low powered systems, so maybe that's why it works with them. On researching, someone mentioned that the power draw on the am4 system during boot could be a tad bit high and my psu components are failing so the protection features in the psu are triggering and shutting itself off to protect the rest of the system.I tested am4 systems out of the cases with only motherboard, cpu and ram to rule out any shorts, but it still shuts off after 1/5 second. I'm going today to the repair person, with my MSI motherboard so he could see for himself the problem with these am4 system. I haven't tested the V850 on higher end Intel system as I don't have access to them.Any thoughts?

author: Hogwild
author_rank: Regular Contributor
timestamp: August 30, 2025, 02:18:19 pm
content: Did you try clearing CMOS on those systems, if possible.Have you removed any case fans or coolers other than the CPU HSF? Some mobos have fan requirements, and if a fan can't get up to what teh mobo thinks is the minimum speed, it will shut everything off.Are you there are no cabling differences? Looks like the V850 is fully modular, so are you using the same PSU cables all situations? Some mfgrs have different pinouts on their cables/PSUs.Have you checked the CMOS batteries? Sometimes a dying or dead one will prevent boot.

author: cruff
author_rank: Regular Contributor
timestamp: August 30, 2025, 02:52:35 pm
content: Have you verified the power requirements of the "failing" motherboards can be met by the power supply? Are the shutdowns just due to overcurrent protection?

author: noto64
author_rank: Newbie
timestamp: August 30, 2025, 03:45:19 pm
content: Quote from: Hogwild on August 30, 2025, 02:18:19 pmI checked system with only the wraith stock cooler fan, cpu and ram only nothing else is attached to the system. I replaced the old CMOS cell with new one. Checked the pinout of the cables and tested them with multimeter. All the cables are what they are supposed to be. No cable differences.Quote from: cruff on August 30, 2025, 02:52:35 pmI just came back with the v850 from the repair shop. I brought my msi board so he could check the psu on that board. The psu powered up when he tried with the msi board, though he just used the 4 pin connecter insted of the full 8 pin cpu connecter. The board stayed powered on for quite some time and didn't show any sign of shutting down after 1/5 second. He told me to take the psu and my board back home, test them with my full system and call him tomorrow to tell what happened.Well, I came home tested the board with both 4+4 pin cpu connecter plugged in and it happened again. It shut itself off after 1/5 seconed, I recorded this to show him just in case. Then I tried with only 4 pin cpu connecter and it booted into bios.I then tried again with both 4+4 pin cpu connecter plugged in and it didn't shut down after 1/5 second this time. But it did shutdown after 7 or 8 minutes while idling in bios.. I left the system as it was for few minutes with the power off from the socket as it won't power on again. I powered it on again after 15 or 20 minutes and it powered on, but shut it self off again after 8 or 9 minutes while in bios.I don't know what in the netherworld is going on with this psu.Any suggestions or ideas? I'm going to call the technician tomorrow morning, he said he can try to come to my house if the psu doesn't work to see what the bleep is going on with.

author: Swake
author_rank: Frequent Contributor
timestamp: August 30, 2025, 07:14:44 pm
content: What changes during 8 minutes of 'doing nothing' ?What has changed after 8 minutes of 'doing nothing' ?What has reverted itself after 15 minutes of power of ?Assuming mains power is stable, the possibilities that come to my mind to answer those questions are: the temperature of the boards and components. Whatever happens seems to have a thermal factor. I'm not including condensation as that is unlikely to solve itself after a 15 min shutdown. It might also be a build-up of static for some reason.What is ambient temperature and humidity level?Do you know what exactly was wrong and repaired on the MSI board that failed multiple times (you got the same board back? or was it replaced?)In order to confirm it is temperature related you could perform some test by influencing the temperature and check if it takes quicker/longer to failed. Do you have a good blower or a compressor blowing lots of air? Or a fridge that you can use to put the thing in for a test.Monitor voltage with your multimeter during the whole duration of the test.Double check the 4+4 pins on all 3 parts PS, cable and MB to confirm these are still in good shape and make good contact (Ohm setting on your multimeter, it is not perfect but far better than by eye).

author: noto64
author_rank: Newbie
timestamp: August 30, 2025, 08:29:52 pm
content: Quote from: Swake on August 30, 2025, 07:14:44 pmI just left the MSI board on bios screen after it booted and let it idle. The temperature of the psu and cpu cooler seems normal when touched and the cpu temp showed at 32 C. The ambient temperature is like 30 C, and humidity like 80% to 95%. (It's monsoon season here right now)The msi board has no problems and has never failed(It has no warranty). It's my Asrock HDV B450 that has failed multiple times on different power supplies and have I've always got a different board when rma. I'm just gonna sell that piece of s\crap board.Also I'm running the system on a ups with an avr. Already Checked the 4+4 pins and all other pins for lose wiring and they seem to make good contact. I don't have blower or even a hair dryer to influence the temperature.Could be just a failing capacitor. Or something else but there's no issues in the msi board. Though my house wiring is actually pretty old, like 20 years or so, and my pc used to be powered on the same circuit that has my refrigerator and when the compressor on that used to turn on the voltage on that circuit used to fluctuate, but I've moved my pc on another circuit and the fluctuations have stopped. But the psu still shows erratic behaviour when I try on any of the circuits in my home.

author: DimitriP
author_rank: Super Contributor
timestamp: August 30, 2025, 11:05:58 pm
content: Quotedump the technician. and dump the power supply.TheEnd.