Re: Anyone here has a Lian Li PC-60 aluminum case?

Posted on 2021-11-01, 11:29

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If it'd be any use, I've got a Yeong Yang case that uses what look like the same standoffs. I could dismantle it and take some measurements/photos (it's a faff, so I'd only want to do this if it'd help)? They're not very good as the thread strips out really easily, so if trying to unplug an ATX …

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Re: Roland sound module dc adaptor

Posted on 2021-10-28, 10:44

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Mind that, if I remember rightly, Roland round power connectors used to have (might still have) centre ground when most other round connectors are centre positive. So you'd probably have to do a little bit of rewiring if using generic adapters.

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Re: Keyboard crashes on old 386 motherboard

Posted on 2021-10-27, 20:26

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I just searched for VT82C42 and found http://www.s100computers.com/My%20System%20Pa … conrtroller.pdf Clock methods are on page 9&10 of the PDF, or 7&8 going by printed page numbers.

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Re: Dataexpert 8049 (socket3) voltage regulator

Posted on 2021-10-27, 19:15

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Looks like the D45H2A is a power PNP transistor and not a stand alone regulator. I'm guessing it's controlled by the LP2951CM chip next to it, which is a low current (100mA) adjustable voltage regulator. Output voltage from the 2951 probably controls the base of the transistor, and the output from …

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Re: Need two caps values for Voodoo4 4500

Posted on 2021-10-26, 23:00

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Is is worth having another look over the board for damage? Have you got pictures of the back of the card? There's what looks like it might be another short on the space for U3. Also might be worth taking the fan/heatsink off and checking for any damage under it. U3_PadDamage.jpg I'm slightly baffled …

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Re: Keyboard crashes on old 386 motherboard

Posted on 2021-10-26, 22:46

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I then started scoping the chip on the working motherboard with the same chip on the faulty one. The main thing that catches my attention is that on the "good" board I have 7.15Mhz on XTAL 1 and XTAL 2. On the "bad" board I only have a clock on XTAL 1, nothing on XTAL 2. Is that relevant? Have you …

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Re: Help with Slot A Athlon System locking up/boot problem

Posted on 2021-10-26, 22:39

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

What was the 120mm fan plugged in to? A motherboard header, or direct on a PSU molex? Given the power distribution fail/fan stopping, I'd have a quick look at what I think are two PTC/thermal resetting fuses near the ATX connector (green components marked 1X1, F3 and F4). If you can check if one …

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Re: Jumper table needed

Posted on 2021-10-25, 22:05

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Can't see anything that looks like it'd be a definite disable (except possibly for the game port). Maybe try removing all the jumpers for a port and see if it can still be accessed? There are a few resistor packs on the board, so I'm assuming that no inputs are being left floating, so it shouldn't …

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Re: Help with Slot A Athlon System locking up/boot problem

Posted on 2021-10-25, 21:12

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Maybe something is overheating? If I understand correctly it was working ok until you started running demos, then it crashed, then would start up ok after a few seconds turned off, but would crash quite quickly after that. It was then ok for a while after you'd stripped it all down, but then crashed …

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Re: Jumper table needed

Posted on 2021-10-24, 20:21

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Good guess, think your Async could be correct but disagree with the PTR ports, close inspection shows PTR3 above PTR1 silkscreen and then down by the IC you see another P which I assume is for PTR2 My main reason for that is because on the other card there is no PTR2 header and no jumpers for it …

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Re: RAM on 286

Posted on 2021-10-24, 19:40

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

... doubt eBayt has replacement need hobbyist supplier. ... Dunno where aknot is based, but quickly checking on ebay in the UK there's a seller offering them for a bit over £5 including postage, so might get lucky. Before that though, Jakethompson1's idea of putting the 16MHz oscillator in place of …

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Re: Jumper table needed

Posted on 2021-10-23, 22:59

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Horun got there first, but I'd already started drawing this, so thought I'd attach my guess as well: IO4S3P_BaseAddressGuess.jpg Largely based on a mix of what I think are the default addresses and assuming that the address selection are in order, and that the existing jumpers are set for the …

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Re: Chicony CH-498B voltage regulator mod help.

Posted on 2021-10-19, 21:42

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So if the 486 dx4 100 consumes 5.22w maximum (cpu-world) and the mic 29152bt can give 3v3*1.5 around 4.95w, something is wrong. So I'll need the Mic 29302, right? What power rating for the resistors? Most ones I've seen are 400mw, is this low? But I'm not used to this, and I'm having trouble to …

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Re: Chicony CH-498B voltage regulator mod help.

Posted on 2021-10-19, 18:59

by

by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So everything depends on the resistor's value and I need to follow the traces that go from the jumpers to the resistors if I understand it well and use a 94.5k resistor in one place to have the 3.3v, maybe ignoring the 4.02v resistor and using the odder ones may be the best. And the resistor right …

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Re: Chicony CH-498B voltage regulator mod help.

Posted on 2021-10-19, 18:13

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So Deksor's board does pretty close to 3.15V - 3.6V in 0.15V steps, and also 4V (does that sound right?). For Hoping's board, it looks like the R1 158k should go nearest JP8, then pick out 4 resistors for the next 4 positions to give whatever voltage is wanted, chosen by putting a jumper on 1-2, …

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Re: Chicony CH-498B voltage regulator mod help.

Posted on 2021-10-19, 17:20

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

weedeewee wrote on 2021-10-19, 16:57: looks like lime Yellow perhaps? [edit to add...] dunno if this makes sense, but using the Vout = 1.24*(1+R1/R2) from the datasheet, and using the 158k as R1, that gives (I think) 94.5k = 3.31V 82.5k = 3.61V 88.1k = 3.46V 102k = 3.16V 70.6k = 4.02V

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Re: Got sold a broken Voodoo 2 -- do I try to fix it?

Posted on 2021-10-19, 10:07

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just speculation as I don't know the card at all, but is there some equivalent of the relay on the original Voodoo for switching between 3D and 2D? Looking at the parts list thread that Weedeewee linked to, there's at least one tri-state buffer (U32 74F125) and one 2*5bit analogue switch (U10 …

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Re: ASUS A7M266 and Nvidia video cards strange behaviour?

Posted on 2021-10-19, 09:49

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you haven't already, is it worth experimenting with the various BIOS settings? I think I remember having a video card that wouldn't work reliably with Fast Write enabled. I'd try turning off 4x and Fast Write, putting Compensation and Drive Strength to Auto and disable AGP to DRAM Prefetch. I …

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Re: Crazy overkill build ideas post here: Oldest motherboard that supports server ECC registered SDRAM?

Posted on 2021-10-18, 19:16

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you wanted, it might be possible to convert the registered to unregistered: Converted registered SDRAM

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Re: AGP slot and burnt +12 volt trace.

Posted on 2021-10-18, 17:31

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by snufkin

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I can't see anything else that jumps out as being odd. Maybe that capacitor you circled in the first post failed short and took out the trace with it. Seems unlikely. I'm still a bit suspicious of the blueish tinge to all the vias on the back. At this point I'd probably solder a wire to replace the …

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