System doesn't boot if new card is slotted home

Hello everyone. Thank you for the replies in advance.

I have the following system :
Mercury Kobian PI945GCM motherboard
Zebronics 450W power supply
1.5 GB RAM
Intel Pentium 4 3.0 GHz
Windows XP 32-bit SP3
Nvidia Geforce 8400GS 512 MB
As you can see, a very basic config.

I recently bought a graphics card(HIS Radeon HD7750 1GB GDDR5, PCIe 3.0), with the intention of upgrading my system one component at a time. But when I slotted the card and fired up the system, it just failed to boot. The system goes in a restart loop, no beep from the CPU. I installed XP drivers support(AMD Catalyst 12.6) and tried with a 500W supply as well(Cooler Master Thunder 500W PSU), even though the required specs read 400W.

Any ideas?
 

topgear

Super Moderator
Staff member
make sure you have the most recent version of the bios - after mounting the gfx card reset/clear CMOs settings using jumper/CMOS battery - if possible check the card on a friend's pc.
 

aloodum

Journeyman
^^^ If possible can you slot in an older gen card, maybe a pci-e 2.0 card like 8800Gt/9600Gt or 2.1 card like gt240 or any equivalent from amd stable and see if the same boots up?
also in bios can you confirm if your PCI-E slot is a 1.0a/1.1 or is running in a 1.0a compatibility mode?
Read some cases where pci 3.0 is having compatibility issues with 1.0 version..
 

RCuber

The Mighty Unkel!!!
Staff member
does the system restart when loading XP or even before that?

I think this issue is related to old driver still installed in your system. start in safe mode and remove the old drivers and try again.
 

d6bmg

BMG ftw!!
There could only be one of the following 2 reasons:
1. PCI-E slot of the motherboard is bad.
2. The PSUs you have tried are bad.

I really think it is the second point that is creating problem.
The zebronics450watt or CM 500 watt PSUs are bad and can't provide rated power.
 

aloodum

Journeyman
does the system restart when loading XP or even before that?

I think this issue is related to old driver still installed in your system. start in safe mode and remove the old drivers and try again.

The system is not even POST-ing..so that rules out driver related issues.
 

aloodum

Journeyman
There could only be one of the following 2 reasons:
1. PCI-E slot of the motherboard is bad.
2. The PSUs you have tried are bad.

I really think it is the second point that is creating problem.
The zebronics450watt or CM 500 watt PSUs are bad and can't provide rated power.

1. PCI-E isnt bad, he has mentioned he has a Nvidia Geforce 8400GS 512 MB working previously on this system.

2.HD7750 needs no extra PCi-E connecter, 75W from the slot is enough for her.
Having said that also note this card will use minimum power when starting up.
In this scenario the CM 500/generic psu with 14-17A on 12V would have easily booted up... ie atleast caused a POST.

that would mean PSU issue as mentioned by d6bmg

Nopes, i doubt that...7750 is no guzzler and needs no pci-e connector.
At startup it has the lowest power draw..a CM 500/genric psu is enuff at this stage.
 

d6bmg

BMG ftw!!
^^ No pci-e connector isn't related to low power consumption.
If a card doesn't have any pci-e connector, it consumes the necessary power from motherboard PCI-E lane and to provide the necessary power, the 4pin/8pin 12V EPS/ATX connector comes into play. If the PSU can't provide enough amps through that 12Volt ATX/EPS connector, the graphics card as well as processor + all other components in the motherboard starved of necessary power to POST, which seems to be the exactly the case here.
 

topgear

Super Moderator
Staff member
^^ if this was a PSu issue the new PSU ie Cooler Master Thunder 500 should have made his pc work with the HD7750Op has bought - but this is not the case - my guess is it's some sort of compatibility issue with pci-e 1.0 ( mobo slot ) and pci-e 2.1/3.0 ( gfx card ) which can be only solved by a bios update if available.
 

Naxal

Little Kid
Mercury is not a good brand, I only see old offices use Mercury since they still make older socket motherboard. This card is simply too new :p for a motherboard meant only and only to run legacy system for basic office duty i guess :(

I guess OP should have thought of Mobo+DDR3+PSU and then Grfx Card !!!

HD7770 perhaps been over kill for the single core P4 3.0 GHz ???
 

aloodum

Journeyman
^^ No pci-e connector isn't related to low power consumption.
If a card doesn't have any pci-e connector, it consumes the necessary power from motherboard PCI-E lane and to provide the necessary power, the 4pin/8pin 12V EPS/ATX connector comes into play. If the PSU can't provide enough amps through that 12Volt ATX/EPS connector, the graphics card as well as processor + all other components in the motherboard starved of necessary power to POST, which seems to be the exactly the case here.

You are mixing things up....
Firstly He isn't using the 4 pin /8 Pin auxillary PCI-E power connector to his card..is he?
Secondly the 4/8 pin EPS/ATX connector your talking about is actually the one that plugs near ur cpu...the one that supplies +12V,+5V to the cpu...The EPS standard came in to handle better power management on multi core, power hungry component systems...Even a generic smps provides enough Amps on the 4 pin 12V connector for MR cpu

^^ if this was a PSu issue the new PSU ie Cooler Master Thunder 500 should have made his pc work with the HD7750Op has bought - but this is not the case - my guess is it's some sort of compatibility issue with pci-e 1.0 ( mobo slot ) and pci-e 2.1/3.0 ( gfx card ) which can be only solved by a bios update if available.


Exactly thats what i suspect...thats why i asked him to check if his his mobo is forcing the pci-e slot to work at 1.0a or 1.1
 

d6bmg

BMG ftw!!
You are mixing things up....
Firstly He isn't using the 4 pin /8 Pin auxillary PCI-E power connector to his card..is he?
Secondly the 4/8 pin EPS/ATX connector your talking about is actually the one that plugs near ur cpu...the one that supplies +12V,+5V to the cpu...The EPS standard came in to handle better power management on multi core, power hungry component systems...Even a generic smps provides enough Amps on the 4 pin 12V connector for MR cpu

I am talking about 4/8pin ATX/EPS connector which happens to be near CPU socket.
@topgear: PCI-E3.0 is backward compatible to PCI-E2.0 and PCI-E 2.0/2.1 is backward compatible to PCI-E1.0/1.1
But if compatibility is the problem, BIOS update (if there is any) from a manufacturer like mercury can hardly help..
 

aloodum

Journeyman
I am talking about 4/8pin ATX/EPS connector which happens to be near CPU socket.

Good. But if your talking about PCI-e slot utilising from that branch, then its not the case. EPS 12V specifically aims to address multicore power hungry cpus.The original atx had 4..EPS took it all the way to 8..C2D/i3 all do well with the 4 pin 12V , a phenom X6 needs all 8.As a result all of the EPS certified power supplys actually offer the 8 pin connector as 2X4 connector to be backward compatible. Its the 24 pin connector that supplies the rest of the components on the mobo, including the PCI-e slot. In case a card needs more than the 75W limit of the PCI-E slot, he/she :) fetches the extra from the auxillary PCI-E power connector.

Thats why, its far fetched to say that a CM 500 wont let a c2d @ stock and a 7750 reach POST.
 

topgear

Super Moderator
Staff member
I am talking about 4/8pin ATX/EPS connector which happens to be near CPU socket.
@topgear: PCI-E3.0 is backward compatible to PCI-E2.0 and PCI-E 2.0/2.1 is backward compatible to PCI-E1.0/1.1
But if compatibility is the problem, BIOS update (if there is any) from a manufacturer like mercury can hardly help..

I know they are backward compatible but some older nforce chipset based mobos had compatibility issue with pci-e 2.1 gfx cards - only a bios update by mobo manufacturer could fix that though not every motherboard manufacturer cared to release a bios fix for older nforce mobos and that's why nvidia never did release any pci-e 2.1 gfx cards for better compatibility ;-)
 

topgear

Super Moderator
Staff member
^^ Nope OP's mobo is based on 945GC chipset and a half baked bios can also cause compatibility issue .... and though old nforce chipset has most issue the issue was not limited to nforce only and that's why many mobo manufacturer released bios update to fix compatibility issues even for intel chipset motherboards.

and have a look at this quote ( gt it from tom's HW forum )

It's not about the cards not being backwards compatible, it's about the motherboard being forward compatible with PCIe 2.1 cards. BIOS updates are required to allow PCIe 2.1 cards to work in PCIe 1.0 and 1.0a boards. Some (many considering their age) motherboards lost manufacturer support prior to PCIe 2.1 being introduced, therefore PCIe 2.1 devices don't work in them.

I think this clears things up ..
 
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