Monitor/PC won't boot when both ram sitcks are connected

February 2, 2013 at 14:04:30
Specs: Windows 7, 512+256=768
I have a similar problem.
I'll tell you my pc data first:
Motherboard: 775i65g rev g/a 1.02
Dual core cpu
BIOS reeds:
CPU temp 64°C/143°F (i know it´s high as s---, but here in Buenos Aires it is 35-40°C )
M/B temperature 38°C/100°F
CPU fan speedÑ 2656 rpm
Chassis fan speed 1976rpm
Vcore 1.274V
+3.30V 3.483V
+5.00V 5.241V
+12V 12.342 (sometimes 12.403V)

I have 2 different ram sticks, one is 512mb and the other 256mb. When i put both ram sticks, the pc will start (fans OK, HDD OK, CD OK) but i don't have any image on my screen. I pulled put both ram sticks, and tried 1 at a time, and in both different slots. Whenever i do that everything works OK, i can use windows and everything. But when i put both of them toghether, then i have that problem, monitor just won't start.
I have cleaned it, but not with vacuum cleaner, just with air compressor from a distance, and have waited 2 days for it to "dry" just in case.
Checked capacitors, and everything seems OK.
All fans working.

What can be causing that problem with ram? i mean why if both sticks work correctly when they are plugged one at a time, would make no image appear on the monitor (or prevent pc from booting)?
I´ll try to check if i can borrow a PSU from a friend to check, but any i would apreciate any other ideas.
Thank you all in advance

See More: Monitor/PC wont boot when both ram sitcks are connected

February 2, 2013 at 14:15:45
CPU temp 64°C/143°F - regardless of the room temp, that is too high. How is it that your motherboard is only 38C but your CPU is over 25C higher? Either your CPU heatsink/fan is weak, or dust clogged, or poorly installed.

512+256=768 - that doesn't even meet the minimum requirement for Win7. And you didn't tell us the type of RAM you have, DDR266, DDR333, or DDR400. Are they both the same brand & specs? If not, there might be a compatibility issue between the two. The max your motherboard can handle is 2GB (2 x 1GB), that's what you need for a decent Win7 experience, otherwise you should be running WinXP or Linux. The PSU is not the problem.

Which BIOS version are you running? There have been a dozen updates since the initial release. None of them specifically mention memory fixes, but you never know?

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February 2, 2013 at 14:17:01
I failed to understand from the initial post - has the PC used to work fine with the two sticks inserted simultaneously?

One possible cause is mismatch between the specs of the two sticks. It might be that the system sets the RAM speed of the higher-speed module, so the other one fails to keep up.

Please post the speed and timing specs of the both RAM sticks.

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February 2, 2013 at 14:37:53
Thank you both. Here are my responses:
riider, i know i need more ram, i'm trying to get my hands on some more ram, but meanwhile it will have to do. I can start W7 with just 512. I'll check and post what bios version i have.

Product Details and Features
Product MPN
MPN KVR400X64C3A/512
Key Features
Technology DDR RAM
Form Factor DIMM 184-pin
Capacity 512 MB
CAS Latency CL3
Modules Qty 1
ECC / Registered Non-ECC Unbuffered
Bus Clock 400 MHz
Warranty Lifetime
UPC 740617070422
Product ID 20758698

The 256mb:
AM256D08C2C-PC3200 32M x64DDR 256MB,400MHz,CL3

I just got this pc, and i'm trying to set it up with what i can get my hands on.
It might be what probfixer is telling, but from what i can see both have same latency, same bus clock and are both ddr.

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February 2, 2013 at 15:24:31
You say the computer starts up with both sticks but nothing shows on the screen. No, it's not starting up. The fans and drives are spinning and LED's are flashing but the computer isn't computing.

There must be some incompatibility between the 2 sticks such that the computer can set up one or the other but not both at the same time. The 512 stick appears to be non-ECC but I'm not sure about the 256. The specs for the motherboard say it uses non-ECC.

Regular DDR pc3200 is cheap enough on ebay. You should be able to pick up a pair of 512's for $10.

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February 2, 2013 at 15:58:05
The 512MB stick is Kingston ValueRAM. From their website:

"The components on this module include sixteen 32M x 8-bit (8M x 8-bit x 4 Bank) DDR400 SDRAM in TSOP packages. This 184-pin DIMM uses gold contact fingers and requires +2.6V."

The 256MB stick is some sort of generic brand, Advance Modules? Not much info available. Try manually configuring the RAM settings in the BIOS. I had a look at the motherboard manual & it doesn't appear there's any RAM voltage adjustments, so try these few changes - go to Advanced > Chipset Configuration:

DRAM Frequency = 200MHz (DDR 400)
Flexibility Option = Enabled
Configure DRAM Timing by SPD = Enabled

Save & Exit. Then try both sticks again.

775i65G motherboard manual

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February 3, 2013 at 09:00:30
The 512MB module is listed above as ECC. The link below states the board uses non-ECC RAM. Not sure why the board will run with that stick installed but I would guess the other stick is non-ECC, hence the incompatibility.

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February 3, 2013 at 14:44:22
Otherhill, the 512 is non-ECC.
Maybe there is some incompatibility between both ram, because the pc starts (boots up, i can enter bios setings and such) with one ram stick or the other.

riider, i allready had that options enabled, but still nothing.

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February 3, 2013 at 17:52:38
Guess I read the specs wrong. As riider pointed out, if the required voltage is different the modules may not operate together.

One thing to note, the RAM in the first slot will determine speed and voltage settings for all the slots.

So you might try reversing the installation order. Also, there is an issue with your cooling of the CPU as stated above.

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