VGA detection failure during POST - why?

November 17, 2010 at 12:21:05
Specs: n/a, i5-655K/2x4GbDIMM
VGA detection failure during boot:
New system build: Asus P7P55D-EPRO + i5-665K; Radeon HD5770 GPU (in either of 2 slots) with Iiyama Prolite E1700S on DVI cable or VGA cable with VGA/DVI adaptor; Corsair DIMM (2*4Gb); TX650 W PSU; iCute case; HDD (not yet fitted). On switch on MOBO green LED appears & all fans working OK. Next, MOBO red LED light sequence:CPU - then DRAM LEDs (3 times), then finally VGA LED permanently on preventing access to Setup. I understand from MOBO manual that this sequence implies that the problem lies with with the VGA interface check phase rather than the CPU or DRAM. Any thoughts please - is the fault more likely to be with the GPU or on the MOBO? The Prolite functions on other PC. The iCute case does not appear to have a POST speaker - is this a new trend? (New member). Help would be appreciated.

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November 17, 2010 at 16:59:49
Most (but not all) new motherboards have an onboard speaker. If yours doesn't have one, you need to get one for the case. It's pretty tough to troubleshoot without the BIOS beep code feedback. Plus you should NEVER have mounted the board in the case without benchtesting it 1st, now you have no idea what the problem is.

Start with the basics:

- do you have the 24-pin main ATX plug plus 4-pin ATX12v plug connected to the board?
- are you sure the CPU & HSF are installed correctly?
- is the video card fully seated in it's slot?
- is the 6-pin PCIe plug connected to the rear of the video card?

If all those things check out & you still don't get a display, read this:

How to Bench Test Your System

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November 18, 2010 at 05:37:06
Mickliq, Thanks for prompt reply. I've followed your advice and fitted POST speaker (I note however that MOBO has 4 pin connector, +5v, Grnd, Grnd, Speaker - but the speaker device only has 2 leads on outer pair of 4 pin female block? ). Reverted to minimum 'test bench' config as suggested, including single DIMM. 24 pin ATX +8 pin EATX connections to MOBO + 6 pin PCI-E connection to GPU - all cards & CPU+HSF etc seated properly. POST Sequence visual cues unfortunately exactly as before, stopping at VGA LED ON. No audio response and no video out. All fans inc GPU fan working normally. Any further thoughts?

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November 21, 2010 at 05:59:38
Problem described above still continuing. Given a seemingly working new PSU, CPU and RAM my gut suspicion is either a faulty Asus P7P55D or faulty ATI Radeon HD5770. Which is the guilty party? Any further help anyone?

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June 28, 2011 at 00:39:55
apparently this is a very common issue...I have had to reflash my bios 20 times, and reinstall the HD5770 that I have into the ASUS mobo (Rampage III Extreme)...ASUS customer service sucks, ati customer service sucks, and they all blame each other.... if you find a solution let me know...still reflashing, and trying to get this sucker working...good luck to you.

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