Hi there. I have an Optiplex 755 That will not turn on. I am building the system for myself and need some serious help. When I plug the computer in from the wall outlet, the light on the motherboard lights up and then when I go to turn the computer on, all I get is a solid amber light on the power button and the fan sounds like its running rather quickly (fairly loud). I have a 1GB stick of pc2-5300 RAM sitting on the DIMM 1 slot, 80GB harddrive in place and hooked up, yet nothing. From reading a few other forums, and the manual, I apparently have an internal power issue (duh...i know right). Heres the fun part...This computer came with the energy star 4.0 power supply which allows you to self-test the power supply and etc. So, i did that and the power supply, motherboard, and harddrive, all connected the green light on the backside of the power supply stayed green. Oh, im also running a pentium d 915 i believe on the motherboard. I am stumped as to why it stays soild amber on the power button as im fairly skilled when it comes to computers and i know what im doing (for the most part). Could i have received a bad motherboard? thanks for your time!
Reseat the memory and then what color are these lights on power on?
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Reseated the memory in DIMM_1 and still get the same results. Also, i get no diagonostic lights to come on. 1,2,3, and 4 are all out when i power it on.
Have you fitted the CPU yourself? I dont think a 755 mobo and Q35 chipset with run a Pentium D 915, it will run certain Celerons, Pentium Dual Core Exxxx and Core 2 Duos.
Dell Optiplex 755: Core 2 Duo E6550 @ 2 x 2.33GHZ & 1333mhz FSB / 80GB WD Raptor 10000rpm WD800ADFS / 320GB WD Caviar WD3200AAKS / 4096MB Dual Channel 667MHZ DDR2 RAM / nVidia 8600GTS / Creative Sound Blaster X-FI Xtreme Music / Windows XP Professonal SP3 / Dell Ultrasharp 2007FP
Dell Dimension 5150: P4 630 @ 3.0ghz & 800mhz FSB / 250GB WD Caviar WD2500AAJS / 2048MB Dual Channel 533mhz DDR2 RAM / 8400GS / X-Fi Xtreme Audio / XP Pro SP3 / Dell Ultrasharp 2007WFP
Dell Vostro 200: Core 2 Duo E4400 2 x 2.0ghz @ 800mhz FSB / 160GB Hitachi Deskstar / 2048MB Dual Channel 667mhz DDR2 RAM / 8400GS / X-Fi Xtreme Audio / XP Pro SP3 / Dell E196FP
Sony Playstation3 / Dell Ultrasharp 2007WFP
Yes i fitted it myself. If the pentium D that i have won't work witht eh Q35 chipset, which core 2 duo processor should i look for? thanks!
I am not saying that a Pentium D will definately not work though I very much doubt it and suspect that it is your problem, it uses more power that the later and more effiicient CPUs.
The 755 has a 1333mhz FSB (system bus) so you can use a wide range of processors, the 800mhz FSB E21xx Pentium Dual Cores, the 800mhz FSB E4xxx Core 2 Duos and the 1066mhz FSB and 1333mhz FSB E6xxx Core 2 Duos.
You should also be able to use the 1066mhz E7xxx and 1333mhz E8xxx though not guaranteed, also some of the quad cores.
The best option would be a 1333mhz E6550, E6750 or E6850, guaranteed towork in a 755, the former is massively faster than a Pentium D 915 despite being "only" 2.33ghz, though an E4600/4700 or 1066mhz FSB such as an E6600 would give you a very quick machine.
There are also some Celerons that will run though I am not sure which by model number.
Hi jahnkend26 I had the same issue with an Optiplex 755 small form factor, and then of search by each page or forum on google I could not find the solution, people was saying or thinking that were the power supply but I tested the power supply with a multimeter and was working perfect. but one day I thinking using hot air station, I decided to try apply hot air to all parts of motheboard but only in the solid electronic components of the motherboard but without box. and what was my surprise that after applying hot air and wait for cool, assemble everything again the PC it turn on, this was the solution to me, and amber light disappeared and the green light appeared. if you want try it, I suggest the 968 aoyue station + hot air which you can get inexpensively at amazonbest regards