Re: Asus P55T2P4 REV 3.10 - Dallas

Posted on 2025-05-22, 17:34

by

by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The Dallas RTC module is multifunction device. Without it the motherboard will be missing its CMOS settings RAM and it's real-time clock. Most motherboards will fail their power on self test without it.

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Re: Voodoo Banshee artefacting

Posted on 2025-04-30, 15:15

by

by akimmet

in Marvin \ Video

in Marvin \ Video

Good find, an open or intermittent memory address signal would definitely cause the problems you were experiencing. The damage could have easily occurred during shipment. While not common, EEPROM chips are known to fail on 3Dfx cards. It is entirely possible the card actually worked when the seller …

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Re: Voodoo Banshee artefacting

Posted on 2025-04-29, 19:05

by

by akimmet

in Marvin \ Video

in Marvin \ Video

Considering how collectable 3Dfx cards are, don't just bin it. Collectors are even buying non working examples. Check all the passive components with a multimeter. Cracks in surface mount components can be invisible even under magnification. You might get lucky and discover something you missed …

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Re: 74- and 4000 logic

Posted on 2025-04-25, 23:12

by

by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you are willing to buy some books, "TTL Cookbook" and "CMOS Cookbook" by Don Lancaster are both great reference guides. Both books also have a section with datasheets and pinouts.

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Re: Tantalum recapping project

Posted on 2025-04-17, 23:20

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by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Every capacitor type is a compromise. Surge voltage, parasitic inductance, leakage current, size, and even price. Wet tantalums are the most reliable electrolytic type, but on average cost 100 times more than the alternatives. I have witnessed polymer electrolytics violently fail as well as almost …

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Re: Tantalum recapping project

Posted on 2025-04-15, 14:20

by

by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

No offense taken.

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Re: Tantalum recapping project

Posted on 2025-04-14, 17:22

by

by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I was able to find public copies of some earlier articles discussing field crystallization failures. https://www.vishay.com/docs/49268/tn0003-dcleakfailmode.pdf https://onlinelibrary.wiley.com/doi/abs/10.1155/APEC.3.171 https://onlinelibrary.wiley.com/doi/abs/10.1155/APEC.3.233 Here are several …

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Re: Tantalum recapping project

Posted on 2025-04-10, 17:19

by

by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have had hundreds of tantalums fail short over the years. It is a big enough problem that anything over 30 years old I automatically replace them. Examples from the 1970's and earlier are especially failure prone. The failure mode is well known and its causes. https://www.kyocera-avx.com/docs/ …

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Re: Tantalum recapping project

Posted on 2025-04-10, 03:59

by

by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have had hundreds of tantalums fail short over the years. It is a big enough problem that anything over 30 years old I automatically replace them. Examples from the 1970's and earlier are especially failure prone. The failure mode is well known and its causes. https://www.kyocera-avx.com/docs/ …

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Re: MS-4132G, a nice 486 motherboard crippled by an awful BIOS... and a solution!

Posted on 2025-04-10, 01:07

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by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'll add A75H to my collection. This is one I haven't seen before. When I get a chance I'll have to see what BIOS core this one is.

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Re: Tantalum recapping project

Posted on 2025-04-09, 22:05

by

by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Using non polymer SMT tantalums is ill advised. When they fail and explode, they ruin the pcb. Any blackened fiberglass will become conductive. At least with leaked electrolyte, there is a chance you can repair damaged traces. If you insist on using tantalums, ALWAYS derate the voltage specification …

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Re: What operating systems are available for SUN Ultra 5 system?

Posted on 2025-03-05, 21:09

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by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

UltraSparc is too new for NeXTStep/OpenStep for Sparc. Most modern Linux distributions have become too bloated to be useful without several Gb of RAM. Any modern web browser is out of the question for the same reason. Solaris is certainly going to be the best operating system for the platform. …

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Re: 8-bit ISA Network Cards with DB15 connectors?

Posted on 2025-02-21, 18:36

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by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There are tradeoffs to both methods of signaling. In the case of ethernet, UTP is clearly the better choice. DSL is an excellent example of how not to do things. Implementing high frequency signaling over cabling that was barely adequate for telephone use. DSL was never as insane as Broadband over …

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Re: 8-bit ISA Network Cards with DB15 connectors?

Posted on 2025-02-21, 05:05

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by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

A "real" RJ45 connector is keyed, it will not fit an Ethernet jack. It was a common ordering mistake long ago. In fact there is more than one standard for contact spacing, making things even more confusing if you are crimping your own cables. https://www.arrow.com/en/research-and-events/articles/ …

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Re: SD Cards Suddenly Becoming Harder to Find?

Posted on 2025-01-22, 20:49

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by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Fake SD cards are so prevalent on Amazon and other online stores, I can understand the reluctance to buy them there. Especially since Amazon has been known to mix stock from legitimate sources with counterfeit. I haven't had any more issues with troublesome SD cards since I quit buying them online. …

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Re: PCI ssd adapter?

Posted on 2025-01-07, 20:03

by

by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There are also relatively cheap 44pin IDE native SSDs available now. Here is an example I found from a quick ebay search. There are probably better deals out there. https://www.ebay.com/itm/256678784499

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Re: Non-x86 Systems: They are pulling me back in, do you guys also hear the call?

Posted on 2024-11-24, 14:35

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by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

My intrest in non-x86 was mostly concentrated on UNIX variants and workstations. I still have a NeXTStation Turbo. Along with entirely too many Sun and SGI machines. I was concentrating on bringing as many back up as possible. Unfortunately I haven't had the drive to keep going. One of my r5k Indys …

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Re: Don't rely on Google AI for repair advice

Posted on 2024-11-20, 02:15

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by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

One would hope everyone already knows by now not to trust anything that comes from an "AI" algorithm. Reminders of how bad they still are is important.

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Re: Kingston Turbochip 133 (Am5x86). How to change the multiplier?

Posted on 2024-11-08, 20:04

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by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'm fairly certain Kingston intentionally chose WT mode for maximum compatibility. Many early 486 boards had DMA memory corruption bugs with WB enabled. I'm fairly certain any multiplier mod would require soldering. There are no jumpers that I recall on my Kingston turbochip.

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Re: Slot 1 motherboard died just as my project was coming to completion

Posted on 2024-11-01, 19:15

by

by akimmet

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The burning smell was likely a shorted tantalum. That is where I would concentrate on first. Unlikely. Tantalums almost never burn out without leaving a (serious) mark on the board. The most common failure mode for tantalum capacitors is to fail shorted. They don't always burn up. Sometimes a fuse …

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