Dell system 200 memory failure errors

[modem7]

I occasionally had a problem when it failed to start and found if i briefly connected the two reset pins it restarted and went on to pass post.

It is possible that when the POST detects a warm boot, it skips the tests of the RAM subsystem. I.e. POST author may have been thinking, "A warm boot/reset. Testing the RAM subsystem is comparatively, a long process. I will make the POST end quicker by not testing the RAM subsystem; that having been done when the computer was powered on."

When you do the reset, do you see the POST testing the RAM subsystem ?

Ive checked all the jumper wires I soldered on and all are still connected so could you please help trace this latest memory error.

Present symptom: In bank 0, bits 0 to 7 are not functional.

For all 18 RAM chips in bank 0, verify that the following pins connect to the same pin on the other RAM chips: Pin 1, pins 3 to 13, pins 15 to 16

 

[roadrash]

Present symptom: In bank 0, bits 0 to 7 are not functional.

For all 18 RAM chips in bank 0, verify that the following pins connect to the same pin on the other RAM chips: Pin 1, pins 3 to 13, pins 15 to 16

I cant really say what happened but did as you said and rechecked all connection and as I went along I changed all the jumper wires I put on to a smaller gauge to make more room between each other. Then After all connections checked ok I turned it on and it started up. Then I got back to where I was before in that I setup the bios and rebooted. Then I keep getting the error "no boot device available" I have the hard drive controller in and all cables connected. Same with the floppy its all connected with a boot disk in it. The bios is set for a 1.2mb floppy which it is and hard drive set to type 2 which is. Could something else gone wrong besides these memory errors.

 

[modem7]

Then I keep getting the error "no boot device available" I have the hard drive controller in and all cables connected. Same with the floppy its all connected with a boot disk in it. The bios is set for a 1.2mb floppy which it is and hard drive set to type 2 which is. Could something else gone wrong besides these memory errors.

Yes, possible.

One (not only) thing common between the IDE hard drive and floppy drive is +12V. Does that measure good (at either drive) ?

At some point in the POST, do you see the floppy drive's light turn on, and hear head carriage movement ?

 

[roadrash]

One (not only) thing common between the IDE hard drive and floppy drive is +12V. Does that measure good (at either drive) ?

At some point in the POST, do you see the floppy drive's light turn on, and hear head carriage movement

I decided best thing to do was put in a known good working PSU from my other System 200 (386) as its identical externally and when the computer is turned on it stops saying "no bootable device" and instead showed a message that I have seen before on this system at one point and that is "cannot boot from or read hard drive.and press F2 for setup or F1 to boot". If I press F1 it just hangs and eventually fails. and repeats the option for bios or retry. At no point does the floppy light come on. So there must be something wrong other than the PSU. I was suspicious of the PSU when you said mainly because I did re-cap it but now ive tried a known good PSU I know its not that. However just for know I will keep this known good PSU in until we can trace and rectify this problem.

 

[modem7]

I decided best thing to do was put in a known good working PSU from my other System 200 (386) as its identical externally and when the computer is turned on it stops saying "no bootable device" and instead showed a message that I have seen before on this system at one point and that is "cannot boot from or read hard drive.and press F2 for setup or F1 to boot"

If you have seen that message before, maybe your hard drive is intermittent in some way (or was intermittent before, but now permanently bad). Maybe after some hours of turning, the drive will come good. Quite a few possibilities.

It would be good to get a DOS boot happening via floppy, so that diagnostics can be used to see what is happening with the hard drive controller+drive.

Something to try would be to do a decent clean of the finger contacts on the controller, and re-seat cables.

At no point does the floppy light come on.

I am unfamiliar with the Dell System 200.

Could it be that in SETUP, the boot order is "C,A" and, finding a hard drive, the POST does not do anything with the floppy drive.

You could try removing the hard drive from CMOS SETUP. That would force the POST to attempt a boot from the floppy drive (assuming that one is set up in CMOS SETUP).

Could it be that you did not reassemble the computer properly. IDC connector off by one set of pins, etc.

So there must be something wrong other than the PSU.

But still, there must be something wrong with the first PSU, because the message of "no bootable device" is no longer appearing.
You could confirm that by temporarily putting the first PSU back in.

One (not only) thing common between the IDE hard drive and floppy drive is +12V. Does that measure good (at either drive) ?

I still want you to do that. I do not know the design of the PSU in the Dell System 200. Maybe if something faulty (motherboard/cards/drive) overloads the +12V line, the +12V shuts down but leaves the other output voltages going.

 

[roadrash]

I still want you to do that. I do not know the design of the PSU in the Dell System 200. Maybe if something faulty (motherboard/cards/drive) overloads the +12V line, the +12V shuts down but leaves the other output voltages going

I get a voltage of 11.84v.

 

[modem7]

I get a voltage of 11.84v.

Good. So we rule out nil/low +12V out of the possibilities.
Back to what I wrote earlier:

"Could it be that in SETUP, the boot order is "C,A" and, finding a hard drive, the POST does not do anything with the floppy drive.'

"You could try removing the hard drive from CMOS SETUP. That would force the POST to attempt a boot from the floppy drive (assuming that one is set up in CMOS SETUP)."