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dolphins
Clean Up Our Oceans
Premium Member
join:2001-08-22
Westville, NJ

dolphins

Premium Member

"No Signal" message on monitor screen

I'm working on a friend's daughter's machine which she uses for school. Specs: »h10025.www1.hp.com/ewfrf ··· =3245048

Owner says monitor has been randomly going into sleep-mode for a few weeks/months but would come back up after 8 hours or so of no use.

When I power up the monitor I get a black screen and then a “No Signal” message on screen then it immediately goes into sleep-mode (the light goes from green to amber).

No beeps from motherboard speaker.

Monitor is good, I checked it on another computer.

I reseated the memory sticks but no results.

Installed new CMOS battery with no results, checked battery with volt meter and it is good.

Power supply seems to be working fine, computer powers up, all fans are working.

HDD activity light stays solid from boot until I power it down.

This machine has an integrated GPU. I installed an old PCI card (PNY Geforce MX 4000), plugged the monitor into it but still I get the same “No Signal” message as soon as I power up the monitor. The card worked fine when I took it out of another machine a few years ago, I have kept it in its original antistatic packaging.

Is there a quick way to check if the MB is bad?

JimE
Premium Member
join:2003-06-11
Belleville, IL

JimE

Premium Member

Sounds like it isn't completing POST.

I would strip the board (ie: nothing connected except the cpu and power supply) and power on. You should get BEEP/ERROR codes for missing RAM. (if not, it's the motherboard/cpu or power supply). Add the RAM and power on. At this point, you should have video. If not, likely the motherboard/video.
southietech
join:2000-12-02
Boston, MA

southietech to dolphins

Member

to dolphins
See if you can get into the bios and set the video manually instead of auto.

dolphins
Clean Up Our Oceans
Premium Member
join:2001-08-22
Westville, NJ

dolphins to JimE

Premium Member

to JimE
said by JimE:

Sounds like it isn't completing POST.

I would strip the board (ie: nothing connected except the cpu and power supply) and power on. You should get BEEP/ERROR codes for missing RAM. (if not, it's the motherboard/cpu or power supply). Add the RAM and power on. At this point, you should have video. If not, likely the motherboard/video.

Ah, I did do that once but the memory was installed when I did it. I'll give that a try tomorrow.

Thanks
dolphins

dolphins to southietech

Premium Member

to southietech
said by southietech:

See if you can get into the bios and set the video manually instead of auto.

There is absolutely no access to anything, it doesn't POST. All I see is a black screen except for the moment the "No Signal" message pops up then the monitor goes immediately into sleep-mode.

Cat Scratch
join:2005-06-27

Cat Scratch to dolphins

Member

to dolphins
No guarantees here but try this as it has worked in the past for me.

Remove the power cord from the wall socket (or pull the cord off the PSU).

Pull the battery and move the CMOS Clear jumper to the other set of pins. Leave it there for 10 seconds or so, then move it back to the first set of pins.

Re-attach the power cord, but leave the battery out of the system and hit the power button. Count to ten, then turn off the system.

Replace the battery and try to power the system back up again.

Any luck?

Raible
join:2008-01-23
Plainfield, IN

Raible to dolphins

Member

to dolphins
said by dolphins:

Power supply seems to be working fine, computer powers up, all fans are working.

Given that you can't get this thing to POST, I'm not sure how you can be certain of this. I'm not saying it's the PSU, but I am not sure I'd rule it out yet either. Do you have another PSU you can throw in there to double check?

dolphins
Clean Up Our Oceans
Premium Member
join:2001-08-22
Westville, NJ

dolphins to JimE

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to JimE
OK, I disconnected everything I could (sound and video are integrated) from the MB and removed the RAM, there were no beeps or sound of any kind except for the fans.

I checked, rechecked and triple checked that all power and data cables are properly reconnected and that the RAM is reseated properly.

The HDD activity light does not come on anymore after reconnecting. Now that I think about it, I don't think the HDD light was coming on before either. There was a lot of natural light in the room when I first examined it and I think I mistook the glow of the power light for the HDD light since they are close in proximity.
dolphins

dolphins to Raible

Premium Member

to Raible
said by Raible:

said by dolphins:

Power supply seems to be working fine, computer powers up, all fans are working.

Given that you can't get this thing to POST, I'm not sure how you can be certain of this. I'm not saying it's the PSU, but I am not sure I'd rule it out yet either. Do you have another PSU you can throw in there to double check?

No, I wish I did have another one or a PSU tester. I guess I'm gonna have to invest in one if I'm going to be this involved in fixing computers.
dolphins

dolphins to Cat Scratch

Premium Member

to Cat Scratch
I've had the battery out a few times. Resetting the jumpers and removing the battery does exactly the same thing. You only need to do one or the other. By resetting the jumpers you are shorting the power coming from the battery, like flipping a breaker off and on again. Did you ever flip the main breaker in your electric panel and then have to reset all the digital clocks in your house? It's the same thing.

Cat Scratch
join:2005-06-27

Cat Scratch

Member

said by dolphins:

I've had the battery out a few times. Resetting the jumpers and removing the battery does exactly the same thing. You only need to do one or the other.

Interesting theory...

But the few full schematics of a PC board and many other radio and television circuitry that incorporates a EEPROM I've seen, shows the second (the middle) pin gets connected to 'chassis ground' when you place the jumper on pins 2 & 3, (pin 3 being tied to ground and pin 2 to the B+ side of the CMOS) effectively draining any residual capacitive power in the CMOS.

Powering up the system with Vcc removed from the EEPROM does other things dependent on the information residing in the firmware.

So no, it isn't quite the same thing as "just pulling the battery".

In other words, following the steps as outlined in my first post didn't work for you? If not, then I apologize for wasting your time.

/20+ years as a USAF Ground Radio Tech

dolphins
Clean Up Our Oceans
Premium Member
join:2001-08-22
Westville, NJ

dolphins

Premium Member

First let me say, I bow to your greater experience.

My statement was based on what I've learned off the internet and my own understanding of electricity. I replied only to pass on what I've learned, it was not meant to be anything but a helpful comment. I will give your suggestion a try.

I must admit though when asking for help on internet forums about something outside the realm of my knowledge I am always skeptical and for good reason. Some internet posters (not in this thread) would have me cast a voodoo spell over the computer, place a chicken bone in the chassis and tape the CMOS battery to my forehead before going to bed.

I thank you for sharing your knowledge.
Kearnstd
Space Elf
Premium Member
join:2002-01-22
Mullica Hill, NJ

Kearnstd

Premium Member

how old is the machine itself, its possible something else went bad. Do you have spare RAM just in case one of the sticks is bad?

Spare ram can of course be a tricky thing with older systems as one may not have the right type. I know I only have as far back as spare DDR2.

dolphins
Clean Up Our Oceans
Premium Member
join:2001-08-22
Westville, NJ

dolphins

Premium Member

The machine is 5 or 6 years old. Unfortunately the only RAM I have left is two PC100 sticks from an old Win98SE machine.

I talked to the owner again and she said the monitor started randomly going into sleepmode as far back as 5 months ago but would come back up after a few hours. I don't know if that's an indication of something or not?

I've tried everything I know of plus the suggestions in this thread but nothing has worked. I've run out of ideas so all I can do now is start replacing parts by process of elimination. If it were me I would keep this machine for spare parts and purchase a new one.

I'm going to recommend that they either have a repair shop that has the necessary testing equipment take a look at it or purchase a new machine.