No POST...No Screen

[PCMan]

I will start from the top. I have a NEC Ready GT200 computer that fails to show a screen. It all started a few weeks ago when the CPU fan started making noise signifying that it was time to change the fan. I purchased a CPU fan from Radio Shack along with a battery for the BIOS. Then I switched out the fan with the new fan, and then I switched the battery (all this done with an ES strap). I then reconnected the power cable, monitor, keyboard, ect. When I pressed the power button the fans started and the HD spun but the two lights on the front of the case stayed orange (one light is for the Power which is supposed to go green, and the other is for the HD). After a minute or so the HD light goes out but the power light remains orange (the lights on the two CD drives also light but no floppy light through the process). There is no screen output, and no beeps (there is an internal speaker and it works). I immediately thought that the BIOS was messed up from the removing of the battery. But since the floppy drive does not initiate it is not searching for a BIOS flashing (I did, however, try flashing it with both a floppy and CD). I have traded power supplies, the monitor works, and have gone down to the bare bones setup.


I have gone down through Sylvander’s Flow Charts (thank you Sylvander…great charts!!) but end up at the “System Board or something on it is faulty”. I did notice, however, that with a bare bones setup the power light turns to green but still no screen or POST. This is very frustrating because I know that changing a fan and a battery should not cause this. I will list, below, the computer’s specs that I have gathered so far (NEC is very skimpy on their documentation…it is all in PDF files on the HD…like that is supposed to help when you can’t even boot. I did however transfer the files to another computer and was able to read the documents…none of them helped). I hope that someone will have a suggestion; I am thinking about ordering a replacement BIOS chip, but would like to get a few opinions before I sink money into it.


NEC Ready GT200
Packard Bell 980 (mobo) with a SIS 530/5595 Chipset
AMD K6 500MH/z CPU
96MB PC100 RAM (2 sticks [32mb and 64mb])
Onboard Video (SIS 530 V/chip?)
AMI Bios
12GB HD
Two CD Drives (one RW, one ROM)
Modem 56K (Card)
Ethernet Card

[Whyzman]

Hello PCMan,
Welcome tohttp://www.pcguide.com/ubb/pcgubb.gif Forums!

I'm not quite sure what the order of events was...

At what point were you attempting to flash the BIOS?

In order to flash the BIOS it would be necessary to have a successful POST with a viewable monitor...

You might want to try clearing the CMOS as per your motherboard manual...then try booting.

[PCMan]

Whyzman -

Sorry if I was not clear in the order of events. I tried to flash the BIOS after these symptoms of no BIOS screen started occurring (thinking that possibly the BIOS somehow became corrupt, but since the floppy drive does not even initiate the BIOS is unflashable).

As for clearing the CMOS with the mobo jumper, I have tried that over and over again along with removing the battery....to no avail.

[Whyzman]

If everything was working fine up to the point of replacing the fan, I would stay with your barebones boot setup and recheck all connections thoroughly. Plugging and unplugging a few times just in case there's been some oxidation on the contacts. Especially reseating the RAM and Video Card.

It seems to happen quite often, that when either moving a computer or changing a part, that somethings gets bumped...

I would go completely barebones if you have not already...no floppy either...just the motherboard, RAM, Video, monitor, and keyboard...

[ziba-june]

Hi,
When you change the CMOS battery, you also clear the content of CMOS like information about your hard drive and CPU, etc. Go to you CMOS and check all those variables to see if any was changed.

[youngsw]

something I would try along with reseating video and ram, try reseating the cpu itself.

Seems you tried everything else, why not give it a shot :)

[Paleo Pete]

Go to you CMOS and check all those variables to see if any was changed.

I'd love to know how to do that with no picture....

I've found that video and RAM are the two things that most commonly need reseating, often either or both have to be reseated a half dozen times. CPU is not a bad idea either, but I wouldn't consider it likely. Yes, I know you have onboard video which can't be reseated just an observation...reseat everything that can be removed, start trying to power up with bare minimum - CPU, RAM, video and keyboard. Once you see a picture, add one thing at a time beginning with floppy.

It might also be a good idea to check for Bad Capacitors (http://www.pcguide.com/vb/showthread.php?t=25482), most of them I've seen were in newer boards than yours, but that's probably because there are more newer ones out there. Also double check to be sure no wires were bumped and disconnected.

Another thing to try that might be worth consideration, pull the CMOS battery and let it sit overnight. Sometimes the capacitors can take a half hour to drain down, and I've also seen one or two that would never boot again for some strange reason...

General question for the techs to consider...this is a fairly old board, K6-2/ 500, anybody think socket creep might be an issue? I've seen it before, but it's very uncommon. (Socket creep occurs due to expansion and contraction caused by heat from starting and shutting down. Over time components can actually move out of their sockets.)

[PCMan]

Thank you Paleo Pete! I will try those suggestions as soon as I get a chance to work on the computer. I have already looked at the capacitors on the mobo....all are fine.

Also Paleo Pete, what do you think about replacing the BIOS? Will just any BIOS that supports the K6 CPU work, or does it need a BIOS made especialy for the motherboard?

[Whyzman]

If you flash the BIOS it is necessary to obtain the download from the manufacturer of your motherboard.

As far as replacing the BIOS, sometimes it is necessary to update a BIOS due to problems that the manufacturer needed to address.

BIOS flashing is not for the faint of heart and a failed BIOS flash can potentially leave you with nothing but an expensive paperweight.

I don't know that you need to attempt this right now. Nothing has been done in your explanation of events that would warrant flashing the BIOS.

Have you reinserted the RAM and rechecked all connections? Are you attempting a barebones boot as suggested??

[PCMan]

I was working on the computer last night....I fiddled around with a few items - the battery, swapping cables, checking jumpers, clearing the BIOS, ect. After a few tries the pre-post screen came up! But the screen was frozen and would not take commands from the keyboard. So I shut down the computer and then immediately restarted it....nothing! the screen appeared just once, and I have not been able to get it to happen again. Do these symptoms ring any bells? Could it be a faulty power supply? I have previously swapped out the power supply, but it did not help. I am tempted to try another swap of the power supply.

[Whyzman]

Are you doing this fiddling around with a barebones system???

If the BIOS is polling PCI devices and hits a conflict it could freeze up. That's the importance of a barebones boot situation. You want as few variables as you can to try to isolate a problem...

[PCMan]

Yes, I have it down to the very bare bones...just the mobo, one stick of 64MB ram (in DIMM slot 1), powersupply connected only to mobo and CPU fan, Monitor pluged into video port, and keyboard to PS2 port. The PCI slots are vacant and video is onboard (no AGP slot) and no power or IDE cables to the HD, Floppy, and CD drives. Should I try setting the jumpers for the front and back USB to disable (they are currently enabled)?

[Whyzman]

Yep, I'd disable them also...

Also, if fiddling...try to mess with only component at a time and then try to boot.

The only other thing would be to remove the motherboard from the case and put it on a non-conductive surface. Just in case the problem might be with the power switch, you can take a flat blade screwdriver and contact the pins that the case power switch is connected to...it is a momentary switch and a quick contact completing the circuit is all it takes...

[ms-fixit]

You said RAM memory in DIMM slot 1 - is there a DIMM slot 0 on the board? Most people don't realize slot 0 should be used before slot 1 - just a wild thought......

[PCMan]

You said RAM memory in DIMM slot 1 - is there a DIMM slot 0 on the board? Most people don't realize slot 0 should be used before slot 1 - just a wild thought......
Thank you for the thought....this motherboard has them labled as DIMM slot 1 and DIMM slot 2 (so slot 1 is the slot 0).

The only other thing would be to remove the motherboard from the case and put it on a non-conductive surface.
Yes, I already have tried that. I took the motherboard out of the case and set it on a piece of cardboard. I started it up but same problem.

[PCMan]

I have been looking around in forums (including this one), and I am finding that this no POST and black screen is a common occurrence. But none of the threads have a solid solution to this, and very few even have a solution. This is very frustrating for me and, I'm sure, for many others. This should not happen just because I changed the fan and the CMOS battery; does anyone have a solution to the problem?

I hope someone will have a suggestion or solution to this, and if so post it. :)

High hopes here. LOL

[Whyzman]

Well, let's concentrate on the fan for a second since messin' with that was the last time things worked.

The fan you picked up, is it a thee wire fan?? It may have a three wire pin jack, but if there are only two wires connected it is a strong possibility that your motherboard not sensing the RPMs of the fan shuts down immediately...

[PCMan]

Well actually, it is a three wire fan, but I have tried using both the original fan and the new one. The old fan was hooked up to the PSU with one of the power cables from the power supply. When I went to get a new fan, I checked to see if the mobo had a three wire fan slot, and it did. So I went down to Radio Shack and bought a three wire fan; I also bought the new battery for the CMOS from there.

So to sum it up I have tried the new three wire fan, and the old original fan. I wonder if somehow the new three wire fan somehow damaged the mobo? I know the three pin slot is for a CPU fan because it is labeled as so.

[Sylvander]

Some points:

Single short beep? [POST successful?]:

YES
1. If prior to this you had RESET THE BIOS, then this would have "FORCE UPDATED THE ESCD". The result of that would be that only the PCI hardware items that were connected at that time would be allocated resources in the ESCD table. If you had reconnected PCI hardware after the reset and before the startup, then those items would not be catered for. This might account for the freeze after successful POST.
CONCLUSION
You should either reset with ALL PCI hardware connected, or at least not add items after reset and before startup.
PCI items = Video Card; IDE controller+HDD,DVD,CD; NIC; USB.

NO
[It was interesting that fiddling with connections produced a (single) successful POST.]
2. You have NO POST.
Perhaps:
A. The PSU is not delivering as it should.
B. CPU, RAM, Video Card, motherboard = faulty or NOT CONNECTING?
C. What if the default BIOS settings do not cater for a 3 wire fan [but are set to cater for a 2 wire fan]? In which case your 2 wire fan should have worked [unless now non-functioning]?

[PCMan]

Thank you for your post, Sylvander:

[Single Short Beep?]

When the computer was running normally, it would never *beep* when it passed the POST screen, so if it does pass the post screen I have no way of knowing if it does.

NO

2A
I have tested the PSU with a voltmeter, and all the voltages are within reasonable amounts. I am, however, thinking about swapping another PSU in, just in case.

2B
I have reseated the RAM many times, and also checked the motherboard power connector. Should I try reseating the CPU? Could the rocking of the heatsink while replacing the fan disturbed the CPU? Also, wouldn't the POST screen still post even with a unseated CPU (though not go all the way through)?

2C
The old fan is actually not a two pin fan. It was connected directly into the PSU (as some of the Pentium fans do). A close example of the old fan would be at this link: http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=273-248

The new fan is this one: http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=273-151 (without the heatsink....I'm using the old heatsink)

[Sylvander]

"it would never *beep* when it passed the POST screen, so if it does pass the post screen I have no way of knowing if it does"
OUCH!
So if the signal cable between the video card and the monitor were loose you'd see no display, and the POST could complete [with no beep], and the video card be enabled, but you'd see no [obvious] sign of this and hear nothing.
I have sounds allocated to the "Open Program" and "Close Program" [whoosh] events, so when Windows begins opening "Start" programs I hear a "beep" for each [even if the monitor is disconnected].

"wouldn't the POST screen still post even with a unseated CPU"
I believe not.
Here's the BIOS Boot Sequence to that point:
QUOTE
"[B]System Boot Sequence
The system BIOS is what starts the computer running when you turn it on. The following are the steps that a typical boot sequence involves. Of course this will vary by the manufacturer of your hardware, BIOS, etc., and especially by what peripherals you have in the PC. Here is what generally happens when you turn on your system power:
1. The internal power supply turns on and initializes. The power supply takes some time until it can generate reliable power for the rest of the computer, and having it turn on prematurely could potentially lead to damage. Therefore, the chipset will generate a reset signal to the processor (the same as if you held the reset button down for a while on your case) until it receives the Power Good signal from the power supply.
2. When the reset button is released, the processor will be ready to start executing. When the processor first starts up, it is suffering from amnesia; there is nothing at all in the memory to execute. Of course processor makers know this will happen, so they pre-program the processor to always look at the same place in the system BIOS ROM for the start of the BIOS boot program. This is normally location FFFF0h, right at the end of the system memory. They put it there so that the size of the ROM can be changed without creating compatibility problems. Since there are only 16 bytes left from there to the end of conventional memory, this location just contains a "jump" instruction telling the processor where to go to find the real BIOS startup program.
3. The BIOS performs the power-on self test (POST). If there are any fatal errors, the boot process stops."
As you see, the CPU & RAM must both be functioning for success.

I always think of one of the things "ON THE MOTHERBOARD" to be the BIOS settings. If you cannot get the POST to complete, then you cannot adjust individual BIOS settings. All you can do is reset to the defaults. And are the defaults OK in your situation? You should ask yourself the question even if the answer turns out to be yes.

"Should I try reseating the CPU?"
I'd say so. It would be nice if you could swap in a known good CPU.

I'm no super expert on this though. Whyzman knows more methinks.

[PCMan]

Thank you Sylvander.

Well it is looking prettly dull for this pile of circuits. But I am thinking of trying a few more things before I lay it to rest. ;) I will try swaping out the PSU one more time, and possibly I will see if I can get a hold of a K-6 processor. Also, what do you think about getting a new BIOS for the motherboard? I am thinking it may help, and I like what this site has to offer: http://www.biosworld.com/

In your experience, what do you think about geting a BIOS to replace it?

[Sylvander]

"what do you think about getting a new BIOS for the motherboard?"
I'll be astonished it that's the cause of the problem.

1. Your PC was working just fine until you got inside the box and fiddled with the hardware. So it's probably a hardware problem.
2. You've cut back to the minimum hardware and still its there, so it's in one of the few remaining items.
3. If you could take a [borrowed] working bare-bones PC and swap in your items one-by-one, I wonder which item would cause it to fail to POST?

[ESPplayer7]

first off, i had my friend put my comp together a while back and its all new stuff with amd proc. socket a mb. i was wondering if all i will need after i format my comp is a windows cd, cause i remember reading something in my mb manual about creating a partition disk or something like that? also i was wondering what it means to flash bios

[PCMan]

first off, i had my friend put my comp together a while back and its all new stuff with amd proc. socket a mb. i was wondering if all i will need after i format my comp is a windows cd, cause i remember reading something in my mb manual about creating a partition disk or something like that? also i was wondering what it means to flash bios
Um...I think you posted in the wrong thread, ESPplayer7. :D