Re: "Real time clock error" on a 286 Motherboard

Posted on 2022-10-13, 18:41

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

rasz_pl wrote on 2022-10-13, 18:06: I mean past the CD4069 What cd4069? Did you mean mc14069? If so, from whic pin? That's what I'm trying to find... Sorry for my cluelessnes...

---

Re: "Real time clock error" on a 286 Motherboard

Posted on 2022-10-13, 17:31

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

trace where the clock is going When compared to the diagram of the 5170 that you posted earlier, it is very similar but not exactly the same. I replaced the pin numbers I was able to identify in the diagram. The main two differences I spotted are: 1. The output at pin 6 is connected to the input of …

---

Re: "Real time clock error" on a 286 Motherboard

Posted on 2022-10-13, 14:47

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I think I figured the probe placement. I measured pins 11 and 10 of the IC, and got a nice sine wave of about 32.7 Khz at the input, and square wave at the output. I guess that means that the crystal is good?

---

Re: "Real time clock error" on a 286 Motherboard

Posted on 2022-10-13, 14:10

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I finally bought an oscilloscope! Now, where do I need to attach the probes to find if the crystal is bad? 😅

---

Re: "Real time clock error" on a 286 Motherboard

Posted on 2022-10-04, 08:21

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

you need high impedance probe to measure crystal signal directly, so clean U26 to see the markings, look at the datasheet and measure on the output of whatever 74 series chip circuit implemented there. Also check if the C50 cap is all right. Or just replace blind :) and hole hell, take that …

---

Re: "Real time clock error" on a 286 Motherboard

Posted on 2022-10-03, 11:43

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Does the clock advance while you're in BIOS setup? If not, the crystal (I'm assuming Y2, 32768kHz) might be bad. Had this happen at least once. It does not. Interesting. It does advance in DOS though.. I guess it is not the same. How can i check the crystal? With oscilloscope? I have only a …

---

Re: 3Com EtherLink III 3C509B-TP

Posted on 2022-10-03, 08:07

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I third that :) Just finished installing one in a 286. Make sure to run the configuration tool to disable PnP and set the IO address. I had some issues with it conflicting with my XT-IDE, so I had to run the configuration once from a floppy so it will change the base address. From there on, it was …

---

"Real time clock error" on a 286 Motherboard

Posted on 2022-10-02, 13:48

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have a 286 motherboard, running the CHIPS & Technologies 82C235 chipset. (https://www.vogons.org/viewtopic.php?f=46&t=57838) I found it to be 99% identical to this board: https://theretroweb.com/motherboards/s/dtk-tech-1636 When I got it, I used an external Tadiran battery (3.6v) and it worked …

---

Re: 5DVX Motherboard does not POST - CODE 41 and continuous beep

Posted on 2021-09-05, 08:40

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Another observation. While poking around the BIOS Flash with a multimeter while the chip was out, I noticed that the VSS pin (16) is kinda shorted with pins VDD (32) and both NC (1, 30). And by kinda, I mean that the multimeter beeps for about a whole second, and then stops. I tried doing the same …

---

Re: 5DVX Motherboard does not POST - CODE 41 and continuous beep

Posted on 2021-09-05, 07:42

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Tried now using a different Flash chip from another working motherboard. After flashing it with the original BIOS I saved I get the same behavior. So I guess it is no a bad chip.

---

Re: 5DVX Motherboard does not POST - CODE 41 and continuous beep

Posted on 2021-09-05, 07:14

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I tried to save the existing bios, but so far without success. I tried both awdflash v5.4 and also v8.99, but although it seems to be able to flash the chip, I was not able to make it save the content of it. I believe I uses all the right flags... I even tried creating a simple autoexec.bat file …

---

Re: 5DVX Motherboard does not POST - CODE 41 and continuous beep

Posted on 2021-09-02, 13:22

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Is there the typical floppy seek before that? If not, then I guess you are indeed seeing the boot block in action. This is very strange, it implies that there is a checksum error somewhere. Are you sure the flash chip, socket, traces on the board are good? You may have severed a trace somehow while …

---

Re: 5DVX Motherboard does not POST - CODE 41 and continuous beep

Posted on 2021-09-02, 12:47

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I created a boot disk with the flash command in the autoexec.bat It indeed seem to work, as in the disk is read and after a while the computer reboots automatically. But the behavior remains the same...

---

Re: 5DVX Motherboard does not POST - CODE 41 and continuous beep

Posted on 2021-09-02, 12:04

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In your video, it's quite clear that the POST code jumps from 0x0d straight into 0x41. The exact sequence when a floppy is connected is as follows: C0, 00, C1, C6, 0C, C3, C5, 01, 05, 0C, 0D, 41, FF Ummm... not sure what to make of it though :) Can you reflash BIOS? And some hq pics? I reflashed it …

---

Re: 5DVX Motherboard does not POST - CODE 41 and continuous beep

Posted on 2021-08-22, 06:30

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I read (here: http://www.bioscentral.com/postcodes/awardbios.htm) that error code "0D" is "Initialize video interface; Detect CPU clock, read CMOS location 14h to find the type of video in use, detect and initialize video adapter". Is it possible that somehow the system fails to detect the cpu speed …

---

Re: 5DVX Motherboard does not POST - CODE 41 and continuous beep

Posted on 2021-08-20, 13:25

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks, but as I wrote, I tried several different PCI video cards and 2 different ISA cards, in all of the slots- and none of them works now. I failed to notice that in your original post, my bad. As for why it goes to FF with floppy, that's because it boots normally, but without a video adapter …

---

Re: 5DVX Motherboard does not POST - CODE 41 and continuous beep

Posted on 2021-08-20, 12:35

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Try another video card, it doesn't seem to like the one you used for some reason. Also try an ISA card if you have one. Thanks, but as I wrote, I tried several different PCI video cards and 2 different ISA cards, in all of the slots- and none of them works now. I got some new observations of …

---

5DVX Motherboard does not POST - CODE 41 and continuous beep

Posted on 2021-08-20, 09:01

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I found on the curb a computer with Pentium 133, 5DVX motherboard (Award BIOS), 32mb RAM, ATI Mach64 PCI and an ISA Sound Blaster 16 (CT2940). Upon power up, a tantulum capacitor blew up :) I replaced it, and after some cleaning, reseating and such, the computer booted. I kept messing with it, until …

---

Re: Fixing eMachines Case

Posted on 2020-11-18, 07:48

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In your case I'm guessing a similar spring lever may have gone here bezel02.jpg or possibly a concealed spring lever might have been located between an inner and outer bezel (does the outer silver bezel actually detach as marked?) bezel01.jpg I think you are right. upon closer inspection there …

---

Re: Fixing eMachines Case

Posted on 2020-11-17, 16:13

by

by anetanel

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

aha2940 wrote on 2020-11-10, 17:21: In the upper hinge of your door there seems to be space for a spring like this one, taken from a Dell machine: Can you point to the place you mean? I was not able to find what you mean..

---