TheAbandonwareGuy wrote:

Horun wrote:

NV20 is a Geforce 3. Probably a Geforce Ti-200 based on the fan and heatsink size. I see a part/board number in top right but can't make it out, can you take take a better "non angled" picture ?

It could be either a Ti 200 or a Vanilla GF3. It's a Dell OEM card, built by creative.

Just got around to testing it. It is a vanilla, 200 MHz core with extremely underclocked RAM (WAY less than a ti200).

FAMICOMASTER wrote:

Also, the monitor is all clean now, but the power button does nothing. The monitor shows absolutely no signs of life, so I'm going to pop the cover on it tonight and see what's going on. It seems that moving the motherboard from the original case also killed it - It just makes one long beep now. How wonderful, two things to diagnose!

If it beeps - it lives. That's my motto. 😉

At least it tries to communicate something, 8253/8254 timer is working and perhaps BIOS too - time for some Landmark Diagnostics (although this CRT would really come in handy because you need MDA/Herc/CGA for it).

HanJammer wrote:

FAMICOMASTER wrote:

Also, the monitor is all clean now, but the power button does nothing. The monitor shows absolutely no signs of life, so I'm going to pop the cover on it tonight and see what's going on. It seems that moving the motherboard from the original case also killed it - It just makes one long beep now. How wonderful, two things to diagnose!

If it beeps - it lives. That's my motto. 😉

At least it tries to communicate something, 8253/8254 timer is working and perhaps BIOS too - time for some Landmark Diagnostics (although this CRT would really come in handy because you need MDA/Herc/CGA for it).

Yeah, I don't have any BIOS diagnostics. My repairs are a bit more simplistic than that - Remove and reinsert every socketed IC. Simplify the configuration until it boots.

I get the feeling it's either the RAM or the 8087-2 that I added. It's got 640K onboard now, and even though the chips were good, I may have damaged them. I'll try reseating them and I'll try removing the 8087-2 as well.

I actually skipped this, but I was tempted as these old Dell's don't show up that often. It was 1€ and had (I presume) an SB 128 in it.

FAMICOMASTER wrote:

HanJammer wrote:

FAMICOMASTER wrote:

Also, the monitor is all clean now, but the power button does nothing. The monitor shows absolutely no signs of life, so I'm going to pop the cover on it tonight and see what's going on. It seems that moving the motherboard from the original case also killed it - It just makes one long beep now. How wonderful, two things to diagnose!

If it beeps - it lives. That's my motto. 😉

At least it tries to communicate something, 8253/8254 timer is working and perhaps BIOS too - time for some Landmark Diagnostics (although this CRT would really come in handy because you need MDA/Herc/CGA for it).

Yeah, I don't have any BIOS diagnostics. My repairs are a bit more simplistic than that - Remove and reinsert every socketed IC. Simplify the configuration until it boots.

I get the feeling it's either the RAM or the 8087-2 that I added. It's got 640K onboard now, and even though the chips were good, I may have damaged them. I'll try reseating them and I'll try removing the 8087-2 as well.

If it's RAM - then try swapping chips from bank 0 to bank 1 and vice versa - a single failed chip in the bank 0 and XTs won't boot.

You can also search for my TurboXT thread where deunan helped alot with pinpointing a problem which resulted in successful repair (motherboard was beeping and wouldn't boot, but those beeps were a bit 'hellish') - in my case it was one of the bank 0 chips and 8253 timer. Although without landmark it would be really hard to find. Lately friend of mine (who is at vogons too) was able to repair his XT motherboard using landmark diagnostics as well...

Saw this at the thrift, at €45 I couldn't resist a boxed C64. At home, at first appearance (running on a improved PSU of course) it seemed fine. Sadly, playing some SID tunes started to make it clear that the SID is dying. It plays the music with all voices, but one voice won't correctly hit all notes, and often goes off-tune. This is a weird issue some dying SID chips exhibit. Swapping the SID into a known good C64 showed it was the chip itself and not the system.

I guess I'll have to look into SID replacements, or find the dead C64 in my house that went missing close to a decade ago. No one at my house knows anything about it, and I stuffed it in the back of my closet back in 2009/2008. It's not there anymore, and I'd have known it if I threw it out... It bothers me because it could have a good SID I could swap in.

But, I suppose I have an excuse to check out SID replacements like the SwinSIDs and ARMSIDs now.

Images removed for copyright reasons.

sf78 wrote:

I actually skipped this, but I was tempted as these old Dell's don't show up that often. It was 1€ and had (I presume) an SB 128 in it.

Are these actually uncommon? I see these all the time, it's really a race between these old Dell Dimensions / Optiplexes, the Pentium 4 Dell Dimension / Optiplexes, and Compaq Deskpro machines.

HanJammer wrote:

If it's RAM - then try swapping chips from bank 0 to bank 1 and vice versa - a single failed chip in the bank 0 and XTs won't boot.

You can also search for my TurboXT thread where deunan helped alot with pinpointing a problem which resulted in successful repair (motherboard was beeping and wouldn't boot, but those beeps were a bit 'hellish') - in my case it was one of the bank 0 chips and 8253 timer. Although without landmark it would be really hard to find. Lately friend of mine (who is at vogons too) was able to repair his XT motherboard using landmark diagnostics as well...

I don't have any ROM diagnostics, nor any EPROMs or a writer. I can barely justify spending the $50 an MDA monitor cost.

I don't think it's the same Turbo XT - This is a DTK Turbo 640, which I have the instruction manuals and electrical diagrams for on minuszerodegrees.

When I power the machine on, it makes one long beep that does not stop unless I turn the machine off. It's at one exact pitch and never changes. One time, I held the reset button down and it changed to a higher pitch when I released it, but when I pressed it again it went back to normal.

I'll try swapping RAM chips around, but I can't see why they would be bad, they just came out of the AST Advantage! 128 in my 286, where they were working fine under Windows 3.1

I'm thinking it might be bad contact.

Daniël Oosterhuis wrote:

Sadly, playing some SID tunes started to make it clear that the SID is dying. It plays the music with all voices, but one voice won't correctly hit all notes, and often goes off-tune. This is a weird issue some dying SID chips exhibit.

Have one C64 with exactly the same issue. The SID passes all 15 tests of the SIDTest, but once all voices are use at the same time, one voice either plays wrongly or nothing at all. But it's not even in all games, independent of the music's complexity. I wanted to swap the SID with a good one, only to find out that this board has not a single chip sitting in a socket. Everything is soldered, so I called it a day and use that C64 mainly for testing now.

Anyway, got one of these today:

Seems like I'm now collecting Gravis PC input devices, as that is my 4th one. 😁

derSammler wrote:

I wanted to swap the SID with a good one, only to find out that this board has not a single chip sitting in a socket. Everything is soldered, so I called it a day and use that C64 mainly for testing now.

I've been fairly lucky on this, all three C64s that I have are mostly socketed. No idea on that missing dead C64, but I did just get a desoldering station (ZD-915) in today, so I have the equipment to deal with a non-socketed board. Just need some practice, but I've been doing some desoldering on scrap boards, so far managed to grab two Z80 CPUs, a V9938 MSX VDC, and two SCART jacks, without damaging them (...at least not too much 🤣 ).

Funny thing is that it's an assy 250407. I own a second C64 with the same assy and that one has every chip socketed from factory. Wonder why they apparenly did that so arbitrarily.

Desoldering wouldn't be a problem, but it means removing the board, ordering a socket, etc. If you have a couple of C64's, it's not the most important thing to do.

I finally got my 4GB IDE DOM and 512MB DDR400 SO-DIMM.

derSammler wrote:

[...]this board has not a single chip sitting in a socket. Everything is soldered, so I called it a day and use that C64 mainly for testing now.

That doesn't surprise me at all, knowing Commodore's history of cutting corners on everything that they could on home computers 😦 I wonder what kind of other unneeded cost-saving measure they took

Pickup up this early 386 AT clone 😀

pinkdonut666 wrote:

Pickup up this early 386 AT clone 😀

Looks good! Did it come with all these expansion cards installed or did you add them? A bit unusual to see all 8 slots filled 😲 and with no less than 5 full-length cards to boot! 🤣

MMaximus wrote:

pinkdonut666 wrote:

Pickup up this early 386 AT clone 😀

Looks good! Did it come with all these expansion cards installed or did you add them? A bit unusual to see all 8 slots filled 😲 and with no less than 5 full-length cards to boot! 🤣

that's exactly how I got it! I've since removed a few cards. bonus points if you can identify the sound card 😉

pinkdonut666 wrote:

Pickup up this early 386 AT clone :) […]
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Pickup up this early 386 AT clone 😀

Very nice..looks very high end! You should inspect the harddisk carefully if you find the driver for the RAM-card 😉

Predator99 wrote:

Very nice..looks very high end! You should inspect the harddisk carefully if you find the driver for the RAM-card 😉

it didn't have a hard drive 🙁 the hard drive had been removed by the previous owner.

80386-16 with the sigma sigma markings. 2mb of RAM on a special 32bit ram card

Oo, nice 386!

I'd love to see what all hardware it has installed - Is that VGA Card full length? Must be something interesting if so. I'm gonna call it now: DTC 5000 series hard disk controller!

FAMICOMASTER wrote:

Oo, nice 386!

I'd love to see what all hardware it has installed - Is that VGA Card full length? Must be something interesting if so. I'm gonna call it now: DTC 5000 series hard disk controller!

Orchid Prodesigner IIS

some sort of Western digital MFM Hard drive / floppy drive card.