|Assuming you have set the CPU settings right, the most likely things are your power supply is faulty, or you're using ram that isn't compatible with the mboard, or it has a poor connection.|
"(Super Socket 7, not backwards compatible)"
It IS backward compatible with older cpu types.
"with and without using board-mounted fan power (due to any RPM monitoring systems)"
This mboard probably does not have a feature that stops the boot or turns off the mboard if no rpm is detected - that generally did not appear in bioses until long after this was made - it should work fine with a two or three wire fan.
I answered questions for about 4 years on another computer support web site that is now dead.
The Pwa...Camaro mboard series (there are several revisions) was the number one mboard FAQ on that site.
I know all about them, but I've never had one myself. I still have lots of info about them on my hard drive.
They were made by Mitac, who made OEM revisions for Compaq, were used in all of the Presario 74xx series, 7350, 7360, and a few other Comaq models, and Mitac also had it's own retail model 5114vu.
At least one revision of the Camaro mboard for the Mitac 5114vu has two DIMM slots instead of three, the space and solder dots where a third one would be is obvious. At least one revision, of the revisions used in Compaqs, has three DIMM slots. The ones in Compaqs may have more connectors (headers; pins) on the mboard - some have only solder dots where pins should be. All of them use the same drivers, and bios updates can be used on any revision.
They have been reported to us to be a good Super Seven mboard.
If you don't have a manual, there are two (main) manuals for them.
Mitac no longer supports their older mboards, but a .pdf version of the manual is available online (the original was a *.doc).
There was also a manual for the Presario 74xx series, but HP has since removed it from the Compaq ftp site where it was.
You could search for it online but you may not find it - 7400.pdf
If you can't find it, Private Message me and I can send it to you.
Neither manual has all the info you need.
The 5114vu manual has a crude front panel (Compaq calls it a button board) pinout diagram; the Compaq manual does not, but it has info about the mboard and the case and parts used in it.
Neither manual has the oddball pinouts for the USB2 header on the mboard - I have the info about that.
Make sure you do use thermal compound, thermal grease, or a thermal pad once you get it to boot - you have to cover the majority of, or all of, the entire cpu top with a thin layer.
You can re-use thermal grease or paste, but don't re-use a damaged thermal pad.
Thermal grease (silicon thermal compound, clearish translucent, not opaque) never hardens; thermal paste sometimes becomes unremovable with time, gluing the cpu to the heatsink forever.
The cpu fan used is not all that critical, but heatsink should be at least 3/4" high, or higher.
It's extremely unlikely two cpus would both not work because they were damged or defective.
Are you using the core voltage stamped on the cpu?
Are you SURE you have it set right? - the markings on the mboard may be confusing.
Consult the manual if you're not sure.
Most K6-2 and K6-III cpus use 2.2 or 2.4v
Some rated above 450 mhz use 2.3v.
These desktop cpus will usually tolerate up .2v above the core voltage stamped on them, but no more - they will be damaged in a short time if you exceed that - and the cpu may not work correctly at 2.2v if it has 2.4v stamped on it. Setting it to the stamped voltage or .1v above almost always works fine. However, they run noticably hotter at more than the rated voltage.
K6-III cpus have a L2 cache on the cpu.
If your mboard has an L2 cache on it, it's used as an L3 cache by the CPU, if the bios supports K6-III cpus - if the bios doesn't, a K6-III cpu is detected the same as a K6-2 cpu, and the cache on the cpu is not used.
In tests I did on a MVP3 chipset mboard ( ~ same as MVP4 without the onboard video), I found these desktop cpus can't be overclocked much.
K6-2+ and K6-III+ cpu's are less common
Note the + - that's stamped on the cpu.
They came out later and were used in laptops - they use 2.0 or 2.1v.
If you set these particular cpus to a core voltage more than .1v more than what is stamped on them they will be damaged in a short time if you exceed that.
In tests I did on a MVP3 chipset mboard ( ~ same as MVP4 without the onboard video), I found these mobile cpus can be overclocked a little, without overheating. However, they do get a lot hotter if you up the core voltage from that specified.
If you have one of those, if you don't see a specified way of setting 2.0 or 2.1 , many mboards have undocmented settings that can achieve that - I may have such info about about this mboard series (I know I do for undocumented fsb settings).
As far as I have been able to determine they are the same thing.
They both have an L2 cache on the cpu, same as the K6-III cpu does.
If the bios supports them, they operate the same way as a regular K6-III.
"When I turn on the system (in any configuration shown above that "did work once"), the LEDs light appropriately, the CPU and PSU fans spin, and when connected the ATA drives power on."
This system will work fine with a decent PS with a capacity of 200 watts or more. If may not if it's an el-chepo 200 watt; it will not if it's less than 200 watts.
Failing or faulty power supplies are common and can cause your symptoms.
Check your PS
They often partially work, fans and hard drives spin, leds come on, yet you get no video and the mboard will not boot all the way.
See response 4 in this:
If you have another PS you can try, you could try that.
This Camaro mboard series has the Via MVP4 chipset, with integrated Trident Blade video in one of the main chips.
"The memory counter will count up to exactly 8mb less than installed RAM (is this due to integrated video using 8mb?)."
Yes. You can probably alter the amount used in the bios settings.
"None of the F keys or the Delete key will allow me to enter setup skipping the memory test. Escape will not skip it either."
Most bioses will not skip a full memory test unless a feature Quick boot or similar is enabled in the bios settings.
It says in the 7400.pdf manual it's F10 to get into the bios Setup (on newer Compaqs it's often F2), but that's IF and only if the mboard has a Compaq bios version
(since you mention a Compaq logo screen that's what you have).
If it has a Mitac bios version, it's Del.
You are supposed to press it while you briefly see "press xxx to enter Setup" or similar, if that appears (it does for the Mitac version).
Or repeatedly press the key - do not hold it down - shortly after booting - it may restart the boot if you press it too soon - you may have to wait till the memory count has just finished.
Sometimes you can't get into the bios if you are having a problem unless you press the key BEFORE you get an error message or the boot stalls.
The video is usually reliable, but if you have problems with it, you could try a PCI video card, which should disable the onboard video when installed, but no feedback I got mentioned that, so I can't confirm that.
"using integrated and add-on video cards (has shown video out only using integrated)"
You may need to use the last PCI slot on the end closest to the middle of the mboard - that slot is usually forced to share it's IRQ with the onboard video - a PCI card other than a PCI video card will probably not work or not work properly in that slot.
The MVP4 chipset supports up to 256mb of ram in each slot, but
- a 256mb module must be one of certain ones that have 16 chips - 8 on each side
- 4 chip 128mb modules will not work at all (the mboard will not boot when it's installed) or will not work properly.
The same may apply to a 2 chip 64mb module.
- some 64mb DIMM modules work only with certain chipsets
- requires you use 3.3v DIMM ram - all SDram DIMMs (almost always labelled PC66, PC100, or PC133) is 3.3v, but early DIMM ram (FPM or EDO) can be 5.0v, and will not work properly.
- this chipset was designed to use PC66 or PC100 ram. All PC66 should work, MOST PC100 will work, but PC133 ram might not.
The mboard can be slightly overclocked if you use PC133 ram, but the problem is there is nowhere that has lists of which PC133 modules work for sure (are compatible) for a model specified to use PC100 modules, max., in it's orginal specs.
It is easy to test for incompatible ram that has caused your mboard to fail to boot.
Make sure you have a speaker or speakers connected to the mboard so you can hear mboard beeps (see your mboard manual).
"....there is no system speaker connector, so I cannot troubleshoot..."
In this case, there are undocmented pins on the mboard that may have originally been for a case speaker, but they are not hooked up to anything on this and other similar Mitac mboards of this age.
From feedback, I was told you have to connect amplified speakers to the onboard sound to the proper port, have them powered and turned on to a reasonable volume, then you WILL hear mboard beeps, even when no sound drivers or hard drive is present.
Remove the AC power to the case/power supply.
Remove all the ram.
Restore AC power.
Try to boot.
If nothing else is wrong, you will hear a pattern of beeps that indicate no ram is installed, or a ram problem.
E.g. for an Award bios or a bios based on one, that's often a beep of about a half second, silence for a half second, a beep of about a half second, silence for a half second, continuously.
A common thing that can happen with ram, even ram that worked fine previously, is the ram has, or has developed, a poor connection in it's slot(s).
This usually happens a long time after the ram was installed, but it can happen with new ram, or after moving the computer case from one place to another, and I've had even new modules that needed to have their contacts cleaned.
See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated:
front panel connector (Compaq calls it the "button board" connector)
Look for the 20 pin position, double row, 10 each side, connector on your mboard
This is numbered like so:
20 18 16 14 12 10 8 6 4 2
19 17 15 13 11 9 7 5 3 1 (manual shows 1 as on this corner, closest to the corner of the mboard)
There should be a 1 or other mark on the mboard beside pin 1.
If you have this in the original Compaq case, or a compatible Compaq case, you have a one piece 16 pin position connector coming from the front of the case and from your "button board" where your power led, hdd led, and power switch are located. One pin in this connector is blocked, and one pin is missing on the mboard connector. It goes on only one way. If the plug is missing, the connector goes on the first 16 pins, the end with no wires on the 1 and 2 pins.
If you are trying to connect to a generic case:
3-4 sleep or standby or "green" led
5-6 hdd (activity) led
11-13 a 2 pin hole Power led connector
OR (supplied by a user) 11 thru 7 - a 3 pin hole Power led connector
15-16 Power switch
19-20 Reset switch
1, 2, 8, 10, 12, 14, 17, 18 - nothing specified.
Pin 9 is reported to be be missing.
Pins 8 thru 14 (4 in a row, 10 and 12 can be missing or no connection) may have been originally been for a 4 in a row pin position case speaker connector (wires only on the ends) but it has been reported they do not work for this purpose.
I have learned from feedback about this mboard that there is no need to connect a case speaker here, and it probably won't work even if you did.
"... all audio, (even error and post beeps), goes through the onboard sound .... and (to your) external speakers."
Polarity of connections (+ and -) may not be not specified in the Mitac or Compaq manual. Led's will either work or they won't - if they don't work connect them the other direction - no harm done if you connect them backwards. The switches have no polarity and will work either way.
There may be one or more + signs beside some of the pins on the mboard, and/or other labelling.
Power switches on the case rarely cause a problem, but sometimes the case button that presses on it can get stuck - check for that. If you suspect a problem with one, briefly shorting the pins for the power switch does the same thing, or connecting the Reset switch, if your case has one, to the pins for the power switch does the same thing - the two are the same type on ATX cases.
Make sure all wiring connections are seated and making good contact with their pins - they should not be loose - try them on one pin at a time if in doubt.
Any of these can cause a long delay while booting, then an error message, or the boot may stall forever:
Some floppy data cable connectors can be installed either way.
Some computers will not boot if one of the floppy data cable connectors is on backwards, or is mis-aligned on the pins on the drive or mboard (if it has no plastic socket).
If it is on backwards, the floppy led is on all the time the computer is running.
Some 40 wire IDE data cable connectors can be installed either way.
Some computers will not boot if one of the ide data cable connectors is on backwards, or is mis-aligned on the pins on the drive (if it has no plastic socket).
If it is on backwards, the hd led usually does not come at all.
This mboard will probably not recognize an IDE drive jumpered as slave when it's by itself on a data cable, and probably won't recognize a drive jumpered CS when it's by itself on a data cable unless it's on the end connector on a 3 connector cable.
A correctly connected defective optical drive.
It is common to un-intentionally damage IDE data cables, especially while removing them - the 80 wire ones are more likely to be damaged. What usually happens is the cable is ripped at either edge and the wires there are either damaged or severed, often right at a connector or under it's cable clamp there, where it's hard to see - if a wire is severed but it's ends are touching, the connection is intermittant, rather than being reliable.
Another common thing is for the data cable to be separated from the connector contacts a bit after you have removed a cable - there should be no gap between the data cable and the connector - if there is press the cable against the connector to eliminate the gap.
80 wire data cables are also easily damaged at either edge if the cable is sharply creased at a fold in the cable.
Try another data cable if in doubt.
Unlikely, but certainly possible.
Examine the ram slots to see if you can see evidence of damage. You will need good lighting and maybe a magnifying glass or similar.
Look for evidence of missing or damaged contacts, melted plastic, and/or black carbon deposits.
If you see that, someone has installed a ram module backwards in that slot at some time and then tried to boot the computer - that ram slot and it's circuits is/are useless and will never work again. Sometimes the mboard will not boot in that case - you could try cleaning up all carbon, and/or any melted plastic that bridges or touches contacts, and/or severing any bridged contacts - sometimes you will then be able to boot the mboard with ram in the undamaged slot(s).