Bashed my head in as to why my Pico modded Xbox would crash'n burn with a 3-boot-attempt and FRAG.

Apparently my LPC rebuild wires (it's a 1.6) had come undone in some places. Redid the wiring and it boots again. The HDD also broke a pin and was preventing the machine from booting. Swapped a temporary 160GB WD Caviar in, and will likely move to a 1TB Seagate over SATA-IDE adapter once I can get it to run at full speed.

This beauty arrived from US today. No cmos battery, booting but beyboard error. Will work kn this, there is an uncontinuity at a line which can be seen visually. Probably done while removing the silicon under battery. Thats my suspect. Any ideas?

fsinan wrote on 2024-05-25, 08:57:

This beauty arrived from US today. No cmos battery, booting but beyboard error. Will work kn this, there is an uncontinuity at a line which can be seen visually. Probably done while removing the silicon under battery. Thats my suspect. Any ideas?

1st pic I can see 2 probably broken traces.

1. passes close to L3
2. goes to C2

Nexxen wrote on 2024-05-25, 09:19:

1st pic I can see 2 probably broken traces. […]
Show full quote

fsinan wrote on 2024-05-25, 08:57:

This beauty arrived from US today. No cmos battery, booting but beyboard error. Will work kn this, there is an uncontinuity at a line which can be seen visually. Probably done while removing the silicon under battery. Thats my suspect. Any ideas?

1st pic I can see 2 probably broken traces.

1. passes close to L3
2. goes to C2

yes, those are obvious and probably the reason.

fsinan wrote on 2024-05-25, 15:28:

Nexxen wrote on 2024-05-25, 09:19:

1st pic I can see 2 probably broken traces. […]
Show full quote

fsinan wrote on 2024-05-25, 08:57:

This beauty arrived from US today. No cmos battery, booting but beyboard error. Will work kn this, there is an uncontinuity at a line which can be seen visually. Probably done while removing the silicon under battery. Thats my suspect. Any ideas?

1st pic I can see 2 probably broken traces.

1. passes close to L3
2. goes to C2

yes, those are obvious and probably the reason.

Let us know if it was that 😉

That's a very easy repair for someone with the right experience. Lightly layered board, enormous gaps around the graces, right at the edge with a generous amount of space to work.

jmphill01 wrote on 2021-10-09, 21:23:

I finally setup a test machine to try and retrieve files from some old MFM hard drives that have not seen action in decades. My setup currently is an old Packard Bell (Socket 7 150 mhz ) paired with a Gotek floppy emulator with Flash Floppy installed. This is the first time I've been successful in such an endeavor as my previous test machine, a Pentium II with a stubborn oem bios that does not really let you disable the IDE controller it seems.

Drive #1 - 10 MB IBM - This was installed in an IBM 5150 which even has it's original 63.5 w psu. It booted right up to DOS on the test machine and I was able to copy all the files I wanted right to the floppy drive (Gotek with blank 1.44mb images). Not the most efficient method but it's the best low effort method I had at this time. After this feat I ran Spinrite 3.1 and this drive had a clean bill of health. Definitely a sweet running drive it seems.

Drive #2 - 42 MB Seagate ST251-0 - This one came from an IBM XT 5160 that was seriously decked out for it's time featuring color graphics, AST SixPak expansion, 3.5'' 720k floppy, math coprocessor, and a DEFINICON DSI-020 68020 coprocessor. In today's money this system as spec'd could easily pay for a new car. Unfortunately it seems that it is too late for the drive unless someone with some expertise can assist or advise in this matter. I was however able to access this drive which gave me some insights of what this machine was used for and copy a small handful of files. Essentially I would hear drive noises and get a 'sector not found' message about 99% of the time when copying a file or accessing certain directories. This is unfortunate as this drive was chock full of interesting development software, source code, and various utilities including a directory with all the software needed to enable the Definicon Coprocessor to actually work. The previous owner it seems may have been an engineer or scientist of some kind, perhaps aviation related.

any chance you could upload the disk image with the DSI software? I have a DSI 785 card that could use some software (and even if the DSI-020 drivers don't necessarily work, there's a good chance some bits are reusable)

Finally my 486dx4 100 + PCCHIPS M919 v.15 works! Thanks retroweb site for the jumper guide. This board has 256kb real cache.

Kahenraz wrote on 2024-05-25, 20:30:

That's a very easy repair for someone with the right experience. Lightly layered board, enormous gaps around the graces, right at the edge with a generous amount of space to work.

Yeah, I have equipment and some experience. I think I’ll be able to handle it. Will share.

Fiddling with some LMSI stuff, got it working. It reads burned stuff as well.

Tinkering with a ECS P6STP-FL+ Ezra C3 800MHz.

Today I've been working on trying to get a PCChips M912 v1.7 motherboard to work, without success. My ISA slot diagnostic board sees the all the 12V and 5V + and -, and I see it turn off the RST and remain with frame and clock, but that's all - never get any POST diagnostic codes/boot codes numbers. even with no RAM, video, or keyboard installed, I believe I should at least get a few codes or beeps or both, so I am not sure what to do at this point. Maybe the flash BIOS is shot. the manufacturer date on the sticker with the serial # is 12/95 so its got the most recent bios... I'll take suggestions.

NHVintage wrote on 2024-05-28, 19:57:

Today I've been working on trying to get a PCChips M912 v1.7 motherboard to work, without success. My ISA slot diagnostic board sees the all the 12V and 5V + and -, and I see it turn off the RST and remain with frame and clock, but that's all - never get any POST diagnostic codes/boot codes numbers. even with no RAM, video, or keyboard installed, I believe I should at least get a few codes or beeps or both, so I am not sure what to do at this point. Maybe the flash BIOS is shot. the manufacturer date on the sticker with the serial # is 12/95 so its got the most recent bios... I'll take suggestions.

Download the bios and program an eprom if you have equipment. Try with new bios.

NHVintage wrote on 2024-05-28, 19:57:

Today I've been working on trying to get a PCChips M912 v1.7 motherboard to work, without success. My ISA slot diagnostic board sees the all the 12V and 5V + and -, and I see it turn off the RST and remain with frame and clock, but that's all - never get any POST diagnostic codes/boot codes numbers. even with no RAM, video, or keyboard installed, I believe I should at least get a few codes or beeps or both, so I am not sure what to do at this point. Maybe the flash BIOS is shot. the manufacturer date on the sticker with the serial # is 12/95 so its got the most recent bios... I'll take suggestions.

How is the RTC oscillator doing?

NHVintage wrote on 2024-05-28, 19:57:

Today I've been working on trying to get a PCChips M912 v1.7 motherboard to work, without success. My ISA slot diagnostic board sees the all the 12V and 5V + and -, and I see it turn off the RST and remain with frame and clock, but that's all - never get any POST diagnostic codes/boot codes numbers. even with no RAM, video, or keyboard installed, I believe I should at least get a few codes or beeps or both, so I am not sure what to do at this point. Maybe the flash BIOS is shot. the manufacturer date on the sticker with the serial # is 12/95 so its got the most recent bios... I'll take suggestions.

Press down on the large QFP when powering up. I had an M919 board that would not POST or give codes but pushing down on the big QFP chip near the memory slots made it work. Then it was fixed by going over the solder joints on that QFP.
PC Chips are kind of known for this because apparently they use 1.2mm PCB thickness instead of 1.6mm.

If that does nothing, get the oscilloscope / logic analyser out and check the data pins on the BIOS EEPROM, if there's data on those lines then it could be a bad BIOS chip. If there's nothing on there, see if there are any buffer chips the BIOS connects to

PD2JK wrote on 2024-05-28, 16:21:

Fiddling with some LMSI stuff, got it working. It reads burned stuff as well.

The attachment DSC_9188.JPG is no longer available

So cool 😀 Is that the one with the non motorised pull out tray or is it the later one, which I think might be 2x speed? Here's mine when it was set up, it should really go in a case sometime: Re: Where do you attach your CD-ROM?

Today I got hold of an NEC MultiSpin 3Xp SCSI CD-ROM drive - the hope is that I can use it with the Toshiba T2450CT it's sitting on since the laptop has integrated SCSI, a sound card but no CD-ROM drive:

It's kind of huge though and the SCSI cable itself is over 1cm thick and not very bendy, so maybe this won't work out great.

It didn't come with the power supply and the DC-jack connector is a weird one I've not seen before, like the Japanese power connectors I see on Sony/Fujitsu/Panasonic laptops but smaller. Looking around it appears that it gets a mention on wikipedia: https://en.wikipedia.org/wiki/Coaxial_power_connector
It's an EIAJ-04 for 10v -> 13v use, while the larger one for laptops is EIAJ-05 which is for 13.5 to 18 volts. Makes sense but I don't have that plug to hand and don't want to order one because I intend to run this drive from a 12v router psu I keep handy nearby. So I opened up the drive and gave it all a good clean, then ran some wires out through the hole for the dip switches, which required cutting back the edge of the PCB under the dip switches with the mini grinding tool.
Now the drive has a regular DC plug for ease of use and the drive appears to be working, very loud headphone amp on it too 😀

When I got inside it I did chuckle at the burn mark I found inside the casing, with evidence of hand soldering a replacement SMD tantalum capacitor inside that sits above that spot, I wonder when that happened? The drive was dirty enough when I got it that it's probably sat around disused for a very long time.

-----------

Drat, the Panasonic KXL-D740 uses the same connector. I must've run it off batteries when I tested it out last. This KXL-D740 is the one I got for this role originally but the NEC Multispin is a nicer colour match for the T2450CT. The D740 was purchased as a bare drive and I've since got hold of the PCMCIA card for it found in an old laptop, but no SCSI > Panasonic PCMCIA card cable and no way to find one, so I can't use it that the way it's intended.

Took my SB16s with buggy 4.13 DPSs, socketed them, and updated them with patched versions from The Soundblaster DSP project thread.

A mostly smooth process - still, not something I had any previous experience doing. I started with the CT2290, since that's the one I'd want to make any mistakes on. Desoldering the original DSP chips was more challenging than I anticipated, probably because it ended up needing a little more heat than I was comfortable with. Anyway, I got away with only having to nudge one trace back into shape. The CT1790 actually went quite a bit worse with the the desoldering, but I was able to get it sorted in the end.

I've briefly tested both in Doom and Duke3d and no hanging note bug!! 👍

Last Saturday I became the proud owner of this GA-6VX7-4X rev. 1.2, it was a flea market find. See something missing? Yup, almost all the caps and the chipset heatsink were ripped off the board. Man, someone must have been in bad need of Aluminum. Anyway, I would very much want to revive the motherboard, but I don't know the caps values. I found the board on Retro Web, but from the pictures I can't distinguish anything. I watched some YouTube videos but without much luck. I guess the big green capacitors are 1200uF/6.3V but the rest remain a mystery to me. Can anybody be of help? I mean, maybe you know where I can find the capacitor list, or you have the same board, and you are able to see the values on the caps. It would be greatly appreciated.

Teodor wrote on 2024-05-29, 05:20:

Last Saturday I became the proud owner of this GA-6VX7-4X rev. 1.2, it was a flea market find. See something missing? Yup, almost all the caps and the chipset heatsink were ripped off the board. Man, someone must have been in bad need of Aluminum. Anyway, I would very much want to revive the motherboard, but I don't know the caps values. I found the board on Retro Web, but from the pictures I can't distinguish anything. I watched some YouTube videos but without much luck. I guess the big green capacitors are 1200uF/6.3V but the rest remain a mystery to me. Can anybody be of help? I mean, maybe you know where I can find the capacitor list, or you have the same board, and you are able to see the values on the caps. It would be greatly appreciated.

Are there actually still capacitors between AGP and first PCI slot? They look really bad beaten up in that case ...

H3nrik V! wrote on 2024-05-29, 07:15:

Teodor wrote on 2024-05-29, 05:20:

Last Saturday I became the proud owner of this GA-6VX7-4X rev. 1.2, it was a flea market find. See something missing? Yup, almost all the caps and the chipset heatsink were ripped off the board. Man, someone must have been in bad need of Aluminum. Anyway, I would very much want to revive the motherboard, but I don't know the caps values. I found the board on Retro Web, but from the pictures I can't distinguish anything. I watched some YouTube videos but without much luck. I guess the big green capacitors are 1200uF/6.3V but the rest remain a mystery to me. Can anybody be of help? I mean, maybe you know where I can find the capacitor list, or you have the same board, and you are able to see the values on the caps. It would be greatly appreciated.

Are there actually still capacitors between AGP and first PCI slot? They look really bad beaten up in that case ...

Yes, there are, and indeed they are badly beat up. I don't know for sure if they exploded or the previous owner went at them with the pliers 😉. This would not be a problem, I have a desoldering station and I guess clearing the holes is doable, but I need the replacement caps values.

Teodor wrote on 2024-05-29, 05:20:

Last Saturday I became the proud owner of this GA-6VX7-4X rev. 1.2, it was a flea market find. See something missing? Yup, almost all the caps and the chipset heatsink were ripped off the board. Man, someone must have been in bad need of Aluminum. Anyway, I would very much want to revive the motherboard, but I don't know the caps values. I found the board on Retro Web, but from the pictures I can't distinguish anything. I watched some YouTube videos but without much luck. I guess the big green capacitors are 1200uF/6.3V but the rest remain a mystery to me. Can anybody be of help? I mean, maybe you know where I can find the capacitor list, or you have the same board, and you are able to see the values on the caps. It would be greatly appreciated.

These were the values off my 6VX7B-4X. Mine was literally the same board as yours except no PPGA support.

CPU caps - 1200uF 6.3v
everything else is 330uF 25v for whatever reason - you can use 1000uF 6.3v or 10v.