VOGONS


Identify motherboard Slot 1 SIS chipset

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Reply 60 of 64, by snufkin

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PC@LIVE wrote on 2021-05-25, 19:26:
L8 + 4.99V | L10 + 4.99V | L11 + 0.02V | L9 + 0.02V | L15 + 4.89V | L14 + 4.70V Of these, both L11 and L9 are connected directly […]
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L8 + 4.99V | L10 + 4.99V | L11 + 0.02V | L9 + 0.02V | L15 + 4.89V | L14 + 4.70V
Of these, both L11 and L9 are connected directly to ground (black wire).
I also measured the voltage of three other inductors L12 L13 L16, the voltages present are these:
L12 + 4.65V | L13 + 4.65V | L16 + 4.99V

Ok, nothing 3.3V then. Where were the other inductors you measured a few days ago (L1 0V | L2 0V | L3 + 4.98V | L4 + 2.50V | L5 + 3.47V | L6 + 4.93V | L7 + 1.77V)?

Looking at the voltages of the PCI PIN by PIN, I have voltages of 3.44V on PIN A6 A7 B7 B8, of 3.30V on PIN A15, of 3.47V on PIN A17 B44, of 3.52V on PIN A34, while in PIN where there should be the + 3.3V I have not found any voltage.

Don't know if those are as expected. Pretty sure A6,A7,B7 and B8 are ok.

Think I'm out of ideas at this point, other than the boring and time consuming task of putting the meter in resistance mode (20k range probably) sticking one probe on a PCI 3.3V pin and then carefully and methodically testing pins on other devices to find what, if anything, they connect to.

Reply 61 of 64, by PC@LIVE

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snufkin wrote on 2021-05-25, 21:04:
Ok, nothing 3.3V then. Where were the other inductors you measured a few days ago (L1 0V | L2 0V | L3 + 4.98V | L4 + 2.50V | L5 […]
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PC@LIVE wrote on 2021-05-25, 19:26:
L8 + 4.99V | L10 + 4.99V | L11 + 0.02V | L9 + 0.02V | L15 + 4.89V | L14 + 4.70V Of these, both L11 and L9 are connected directly […]
Show full quote

L8 + 4.99V | L10 + 4.99V | L11 + 0.02V | L9 + 0.02V | L15 + 4.89V | L14 + 4.70V
Of these, both L11 and L9 are connected directly to ground (black wire).
I also measured the voltage of three other inductors L12 L13 L16, the voltages present are these:
L12 + 4.65V | L13 + 4.65V | L16 + 4.99V

Ok, nothing 3.3V then. Where were the other inductors you measured a few days ago (L1 0V | L2 0V | L3 + 4.98V | L4 + 2.50V | L5 + 3.47V | L6 + 4.93V | L7 + 1.77V)?

Looking at the voltages of the PCI PIN by PIN, I have voltages of 3.44V on PIN A6 A7 B7 B8, of 3.30V on PIN A15, of 3.47V on PIN A17 B44, of 3.52V on PIN A34, while in PIN where there should be the + 3.3V I have not found any voltage.

Don't know if those are as expected. Pretty sure A6,A7,B7 and B8 are ok.

Think I'm out of ideas at this point, other than the boring and time consuming task of putting the meter in resistance mode (20k range probably) sticking one probe on a PCI 3.3V pin and then carefully and methodically testing pins on other devices to find what, if anything, they connect to.

OK thanks, I also don't know what to do except a comparison with another motherboard.
Inductors L1 and L2 are located between the ISA and PCI slots, live the Audio-IN connectors, put a photo to show you.
Instead L3 L4 L5 L6 are on the opposite side, around the SIS 5595, I put a photo for these too.

Attachments

AMD 286-16 287-10 4MB HD 45MB VGA 256KB
AMD 386DX-40 Intel 387 8MB HD 81MB VGA 256KB
Cyrix 486DLC-40 IIT387-40 8MB VGA 512KB
AMD 5X86-133 16MB VGA VLB CL5428 2MB and many others
AMD K62+ 550 SOYO 5EMA+ and many others
AST Pentium Pro 200 MHz L2 256KB

Reply 62 of 64, by PC@LIVE

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Today I checked the PCI PIN connection on another motherboard.
The motherboard is a Soyo Slot1 i440BX chipset, the card is not working but trying to start the + 3.3V LED is on, a sign that the power supply of this line is working.
In short, I checked where the A21 and A27 PINs are connected, I didn't try the others because I thought it wasn't needed, and they are connected directly to the + 3.3V PINs of the power supply (orange wires).
Here this could serve to explain why the + 3.3V LED is off, or that direct connection is not needed for the operation of the cards, or by restoring the connection to PIN A21 A27 and to the others the card could work again ???

AMD 286-16 287-10 4MB HD 45MB VGA 256KB
AMD 386DX-40 Intel 387 8MB HD 81MB VGA 256KB
Cyrix 486DLC-40 IIT387-40 8MB VGA 512KB
AMD 5X86-133 16MB VGA VLB CL5428 2MB and many others
AMD K62+ 550 SOYO 5EMA+ and many others
AST Pentium Pro 200 MHz L2 256KB

Reply 63 of 64, by PC@LIVE

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I come back to this thread because I have some news on how the + 3.3V of the power supply is connected to the motherboard.
Looking for a connector for the AT keyboard, I found a PCCHIPS AT motherboard (BXCEL-ALI chipset), the + 3.3V PINs of the motherboard are connected together, after a track it starts and arrives at an electrolytic capacitor, here I have to check if in this motherboard there is the same connection to the capacitor, in case I will try to test it or eventually replace it, because maybe it is broken since the LED off indicates a problem. Next I will look to see if there is any other link that goes to the PCI slot PINs.

AMD 286-16 287-10 4MB HD 45MB VGA 256KB
AMD 386DX-40 Intel 387 8MB HD 81MB VGA 256KB
Cyrix 486DLC-40 IIT387-40 8MB VGA 512KB
AMD 5X86-133 16MB VGA VLB CL5428 2MB and many others
AMD K62+ 550 SOYO 5EMA+ and many others
AST Pentium Pro 200 MHz L2 256KB

Reply 64 of 64, by PC@LIVE

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snufkin wrote on 2021-05-25, 21:04:
Ok, nothing 3.3V then. Where were the other inductors you measured a few days ago (L1 0V | L2 0V | L3 + 4.98V | L4 + 2.50V | L5 […]
Show full quote
PC@LIVE wrote on 2021-05-25, 19:26:
L8 + 4.99V | L10 + 4.99V | L11 + 0.02V | L9 + 0.02V | L15 + 4.89V | L14 + 4.70V Of these, both L11 and L9 are connected directly […]
Show full quote

L8 + 4.99V | L10 + 4.99V | L11 + 0.02V | L9 + 0.02V | L15 + 4.89V | L14 + 4.70V
Of these, both L11 and L9 are connected directly to ground (black wire).
I also measured the voltage of three other inductors L12 L13 L16, the voltages present are these:
L12 + 4.65V | L13 + 4.65V | L16 + 4.99V

Ok, nothing 3.3V then. Where were the other inductors you measured a few days ago (L1 0V | L2 0V | L3 + 4.98V | L4 + 2.50V | L5 + 3.47V | L6 + 4.93V | L7 + 1.77V)?

Looking at the voltages of the PCI PIN by PIN, I have voltages of 3.44V on PIN A6 A7 B7 B8, of 3.30V on PIN A15, of 3.47V on PIN A17 B44, of 3.52V on PIN A34, while in PIN where there should be the + 3.3V I have not found any voltage.

Don't know if those are as expected. Pretty sure A6,A7,B7 and B8 are ok.

Think I'm out of ideas at this point, other than the boring and time consuming task of putting the meter in resistance mode (20k range probably) sticking one probe on a PCI 3.3V pin and then carefully and methodically testing pins on other devices to find what, if anything, they connect to.

Hi sorry, I wanted to thank you for all your valuable suggestions, in the end as you can see I solved it, now the board is working normally, the beeps are gone, even if there is one left at startup (this is normal).

The problem was probably due to a wrong BIOS update or a bad writing, I had to use the uniflash program to solve and write the latest version of the BIOS found online.

This experience I hope will be useful in the future, I'll try to check some other card that tries to start, we'll see if I can get results.

Attachments

AMD 286-16 287-10 4MB HD 45MB VGA 256KB
AMD 386DX-40 Intel 387 8MB HD 81MB VGA 256KB
Cyrix 486DLC-40 IIT387-40 8MB VGA 512KB
AMD 5X86-133 16MB VGA VLB CL5428 2MB and many others
AMD K62+ 550 SOYO 5EMA+ and many others
AST Pentium Pro 200 MHz L2 256KB