My Compaq 500B MT doesn't start.

[Ivigta]

Hi!

I have a problem with my Compaq 500B MT

When I press the Power Button, it just starts up, then displays only the Compaq Logo, but it's freezed, means that I cannot enter in the BIOS or boot up. I tried some things, like changing the RAMs and slots (Since I got two 1GB DDR3 RAMs), then I changed the Power Supply, then I removed all the optional cards, like the Graphic Card, then the HDD, DVD-RW, and left it only with the processor and RAMs. I removed the CMOS battery for a long time, I reseted it few times, but it's the same 😞 I also noticed that during the time that the Compaq Logo is displayed and freezed, the processor, the RAMs and some tranzistors around them are very cold (like the PC is Power Off). And if I remove the RAMs and/or the processor, the PC reacts normally, with the Beep Sounds. Anybody can help me?

Than you and greetings!

[Hanspuppa]

Hello Ivigta, There seems to be a lot going on here. First I should say, you should never touch a motherboard or any motherboard components when the power is applied to it, as in checking the temperature of the components.

Even a slight touch could cause a static discharge that could result in a motherboard failure.

Usually, when a system will not even show the BIOS screen, I would suspect a failed motherboard.

However, there are some components that can cause this as well.

Here  is a link for your system specifications. The beep codes are listed here in the Service and maintenance information.

If you removed or disconnected all the components and the system tried to boot, and gave you some beep codes, it may not be a failed motherboard, but a defective component connected to the motherboard.

First, a VERY IMPORTANT CAUTION. Never boot a compter without the CPU heatsink and thermal paste installed.

This could cause the CPU to burn itself out in just a few seconds.

I would make sure the CPU, with heatsink and thermal paste, is installed. Have no other devices connected, including memory. Boot the system and see if you get any beep codes. If so, add one memory module and reboot the system, and see if you get any beep codes. If so, replace the installed memory module with the other memory module and reboot. See if you get any beep codes. Install the video card if you have one other than an onboard video device.

Since you removed the CMOS battery, the BIOS will be at the default setting. If you can get the system to enter the BIOS, set the time, date and default setting, save your settings and reboot. See how far you can go. If you are successful to this point, you will get an error the no hard drive is found. Now is the time to connect the hard drive and reboot, and see if you are successful.

Hope this helps.

[Ivigta]

So, as far as now, I have done all the steps you said, together with a friend of mine wich is a computer technichian (we have never turned on the system without the processor heatsink and thermal paste, don't worry about that) Now, when I remove the processor and then turn on the system, the motherboard gives no reactions in beeps, when I remove the RAMs, the motherboard gives Beep Codes as usual (Wich means that theres no memory installed), then we tried also installing the RAMs one after other, but the same thing, only the Compaq Logo Appears. We suspect about the processor, my friend will find a working Dual Core Processor, to make the test. So as far as now, there's no progress, and it seems that the motherboard is okay. And thanks a lot for your advices and troubleshootings, I will also contact my technichian and give him your steps, so we can run tests again 🙂

Thanks, greetings 🙂

[dkapaso]

I am experiencing the same problem, and have gone thru the same steps but nothing works, please help guys!!!!!!!!!!!!!!!!!!!!!!!!!!

[KrimRon]

Same thing has happened with the same computer to one that we have purchased with my company.

At first I thought as everyone else has though I'm sure and replaced the power supply (To my dismay its fresh out of the box and shouldn't have a bad power supply at all).

After changing the power supply to three different units that all tested good, the computer still will not boot. It won't even power on, no fans, no beeps and certainly no display.

This is very frustrating because it is clearly a bad motherboard. HP has had quality products for a while and I purchase many of them through work because I like reliability just as anyone else would. This is the first and ONLY time I have ever unpackaged something and it didn't work properly in the way of a computer unit.

I have removed the jumpers from the power up and LED's on the board and used a key on the power prongs, this doesn't even work so it has to be a good connection on the board just the board is fried for some reason. Inspected the capacitors and modules, there is no expansion or bad sauder spots....

Any suggestions or anything I am missing would be greatly appreciated, as I do not have another computer in my inventory and need this fixed pretty quickly. Not saying I won't buy anymore HP products but this has definately put a notch in their reliability for me.

[jijos]

hi. am experiencing same problem. my HP 500B MT shows no sign of life at all...then comes on after a very long while. i've tried to switch the powersupply, RAM, processor, clearing CMOS and nothing seems to work... Anybody with a solution to this headache. Am a comp tech. but this one has got me down.....

[HardBeatZ]

Hello jijos,

So you press the button on your computer and nothing happens for a long time and then it eventually powers on, correct?

Steps you have done

- Replaced power supply
- Replaced RAM
- Replaced processor
- Cleared CMOS

That leaves us with the one core component that aides with a computer booting up and that's the motherboard that is likely at fault.

[mrjijos]

At last av cracked the problem. The problem is with temperature... i discovered this when i warmed the motherboard with a room heater, it came on immediately after switching it on. Now i have to repeat this procedure every time i want to use the computer. its frustrating. The room is not that cold @ 20 - 30 degrees celcius.
I researched on the net and found out that the problem would be a component referred to as a thermistor on the mobo. So is there a solution to this problem? Somebody help....

[HardBeatZ]

Hello mrjijos,

Thermal sensors are not something that can be just changed out. Your best bet is to obtain a new motherboard.

[advi]

hello excuse my English,
I have a problem with my old PC. After you run will not execute any action, does not even image in the monitor, hdd spinning but the bios does not even basic overview of nothing, I can do nothing, or configuration as if bios bios existed. Just a black screen. I tried to replace the ram, but nothing. Sound tant issues only if you remove the ram or something else. I do not know where else it could be a mistake, bios reset also can not. Only could be a faulty capacitor.

Thank you for your help