On pretty much all mobos all these +5V wires connect to the same plane on the mainboard. Missing one wire is not going to kill/damage anything. I've run mobos with just one of these connected to external lab PSU and is all still works fine. Are you sure you didn't plug the two AT plugs into your motherboard wrong? Like swapped them place (the easiest mistake to make) or both shifted one pin (this sadly does kill mobos)?

Do not touch any parts on the mobo just yet. Resistor arrays or not. Maybe you are not measuring them properly, it's easy to make such mistakes when you rotate the mobo to get access to leads/pins and you pick wrong ones.
POST card can help but if it displays no codes it's also not all that great. A scope would me more useful if you want to start troubleshooting this mobo properly.

as mentioned, missing one 5V wire shouldn't be a problem.

wrt the resistor arrays, I'd say you're measuring them wrong.
there are many different types of those resistor arrays, but mostly for just single ended signal termination they tend to have one common pin.

Do you have a POST card ?

Deunan wrote on 2025-06-29, 09:03:

On pretty much all mobos all these +5V wires connect to the same plane on the mainboard. Missing one wire is not going to kill/damage anything. I've run mobos with just one of these connected to external lab PSU and is all still works fine. Are you sure you didn't plug the two AT plugs into your motherboard wrong? Like swapped them place (the easiest mistake to make) or both shifted one pin (this sadly does kill mobos)?

Do not touch any parts on the mobo just yet. Resistor arrays or not. Maybe you are not measuring them properly, it's easy to make such mistakes when you rotate the mobo to get access to leads/pins and you pick wrong ones.
POST card can help but if it displays no codes it's also not all that great. A scope would me more useful if you want to start troubleshooting this mobo properly.

Hi, thanks for the reply.
No, i didn't plug them wrong, blacks are always in the middle 😀
POST card doesn't display nothing, but i have 3 of them, and they all works only on PCI slot, on ISA, all 3 of them are showing only voltages, and nothing else. But here on Alaris, there is no light at all 🙁
As for resistors, so they are not 2 by 2 pins to measure like on example- voodoo card?

weedeewee wrote on 2025-06-29, 09:11:

as mentioned, missing one 5V wire shouldn't be a problem. […]
Show full quote

as mentioned, missing one 5V wire shouldn't be a problem.

wrt the resistor arrays, I'd say you're measuring them wrong.
there are many different types of those resistor arrays, but mostly for just single ended signal termination they tend to have one common pin.

Do you have a POST card ?

So i will measure them with first pin and all other with this first (1-2, 1-3, 1-4, .....)?
POST card doesn't show nothing.

Yep, if i measure resistors 1-2, 1-3, 1-4, 1-5,.... They are all ok.
So, if not having one 5V wire didn't fried anything, what could go wrong, the board worked just fine before that. I tried that 5.25 floppy on other board, and it didn't fried nothing else.
I was so happy, it worked on 100MHz 😀

butjer1010 wrote on 2025-06-29, 09:33:

POST card doesn't display nothing, but i have 3 of them, and they all works only on PCI slot, on ISA, all 3 of them are showing only voltages, and nothing else. But here on Alaris, there is no light at all 🙁
As for resistors, so they are not 2 by 2 pins to measure like on example- voodoo card?

So first, no light at all? That can't be, you said you've measured the voltages on ISA slots and they are fine? So some of the LEDs must light up. Can you make a photo, or a short video of the problem?

As for the resistors, there are different packs out there. The "standard" one is pin 1 is the common, and every other pin is just a resistors connected to common pin. All one value. But there are also other kind of packs, like SCSI terminators that have two built-in resistors per pin, and two common connections (for GND and power supply). And other ones are possible too. To measure them properly you first need to understand what the pack does.

Deunan wrote on 2025-06-29, 10:06:

butjer1010 wrote on 2025-06-29, 09:33:

POST card doesn't display nothing, but i have 3 of them, and they all works only on PCI slot, on ISA, all 3 of them are showing only voltages, and nothing else. But here on Alaris, there is no light at all 🙁
As for resistors, so they are not 2 by 2 pins to measure like on example- voodoo card?

So first, no light at all? That can't be, you said you've measured the voltages on ISA slots and they are fine? So some of the LEDs must light up. Can you make a photo, or a short video of the problem?

As for the resistors, there are different packs out there. The "standard" one is pin 1 is the common, and every other pin is just a resistors connected to common pin. All one value. But there are also other kind of packs, like SCSI terminators that have two built-in resistors per pin, and two common connections (for GND and power supply). And other ones are possible too. To measure them properly you first need to understand what the pack does.

I did made a video, but there is no option for upload a video. I got error of no mp4 files allowed. I took a picture of post card when mbo is turned on. There is no beeps from speaker without ram, and there was "sound" before i "destroy" it.

Edit : Pics from 3rd, 5th, 7th and 9th isa pins
This POST card shows voltages on other boards when connected to ISA slots, and fully working when connected to PCI

butjer1010 wrote on 2025-06-29, 10:29:

I did made a video, but there is no option for upload a video. I got error of no mp4 files allowed. I took a picture of post car […]
Show full quote

Deunan wrote on 2025-06-29, 10:06:

butjer1010 wrote on 2025-06-29, 09:33:

POST card doesn't display nothing, but i have 3 of them, and they all works only on PCI slot, on ISA, all 3 of them are showing only voltages, and nothing else. But here on Alaris, there is no light at all 🙁
As for resistors, so they are not 2 by 2 pins to measure like on example- voodoo card?

So first, no light at all? That can't be, you said you've measured the voltages on ISA slots and they are fine? So some of the LEDs must light up. Can you make a photo, or a short video of the problem?

As for the resistors, there are different packs out there. The "standard" one is pin 1 is the common, and every other pin is just a resistors connected to common pin. All one value. But there are also other kind of packs, like SCSI terminators that have two built-in resistors per pin, and two common connections (for GND and power supply). And other ones are possible too. To measure them properly you first need to understand what the pack does.

I did made a video, but there is no option for upload a video. I got error of no mp4 files allowed. I took a picture of post card when mbo is turned on. There is no beeps from speaker without ram, and there was "sound" before i "destroy" it.

Edit : Pics from 3rd, 5th, 7th and 9th isa pins
This POST card shows voltages on other boards when connected to ISA slots, and fully working when connected to PCI

Isn't the post card inserted backwards?
REAR should be the other way.

Without a cpu it won't issue codes, unless this board does something even without one (I don't own one like this).

Eh, I think you're putting the POST card in reverse.. you might have destroyed it like that.

Good chance you’ve shorted something on the board with the reversed post card. It would have also set the PSU into failsafe mode. Turn the PSU off and disconnect it from the motherboard. Plug another post card into the motherboard (the correct way :p). Plug the PSU back in again and see what happens.

I’ve also had dodgy AT to ATX power adapters. Have you got another one to try?

zuldan wrote on 2025-06-29, 10:57:

Good chance you’ve shorted something on the board with the reversed post card. It would have also set the PSU into failsafe mode. Turn the PSU off and disconnect it from the motherboard. Plug another post card into the motherboard (the correct way :p). Plug the PSU back in again and see what happens.

I’ve also had dodgy AT to ATX power adapters. Have you got another one to try?

So the markings "rear" on POST card needs to go to pin1 on isa slot?????
My logic is somehow destroyed also 🙁
Yes, i have few more, but all the same. Now i check everything three times before turning the board on

Nexxen wrote on 2025-06-29, 10:49:

Isn't the post card inserted backwards? REAR should be the other way. […]
Show full quote

butjer1010 wrote on 2025-06-29, 10:29:

I did made a video, but there is no option for upload a video. I got error of no mp4 files allowed. I took a picture of post car […]
Show full quote

Deunan wrote on 2025-06-29, 10:06:

So first, no light at all? That can't be, you said you've measured the voltages on ISA slots and they are fine? So some of the LEDs must light up. Can you make a photo, or a short video of the problem?

As for the resistors, there are different packs out there. The "standard" one is pin 1 is the common, and every other pin is just a resistors connected to common pin. All one value. But there are also other kind of packs, like SCSI terminators that have two built-in resistors per pin, and two common connections (for GND and power supply). And other ones are possible too. To measure them properly you first need to understand what the pack does.

I did made a video, but there is no option for upload a video. I got error of no mp4 files allowed. I took a picture of post card when mbo is turned on. There is no beeps from speaker without ram, and there was "sound" before i "destroy" it.

Edit : Pics from 3rd, 5th, 7th and 9th isa pins
This POST card shows voltages on other boards when connected to ISA slots, and fully working when connected to PCI

Isn't the post card inserted backwards?
REAR should be the other way.

Without a cpu it won't issue codes, unless this board does something even without one (I don't own one like this).

The CPU is soldered to the board, no need for 486 in socket 2 😀

So, another card, inserted right (what an idi0t i am), shows all the voltages, and clk, frame, reset also, only irdy is turned off, but nothing on led display. Do i need to put ram and vga?

butjer1010 wrote on 2025-06-29, 11:31:

So, another card, inserted right (what an idi0t i am), shows all the voltages, and clk, frame, reset also, only irdy is turned off, but nothing on led display. Do i need to put ram and vga?

Is this a different post card or the same one? Try a different ISA slot.

No post codes = CPU not working. Are the jumpers configured correctly on the board? Maybe they are set to use the 486 socket?

zuldan wrote on 2025-06-29, 11:40:

butjer1010 wrote on 2025-06-29, 11:31:

So, another card, inserted right (what an idi0t i am), shows all the voltages, and clk, frame, reset also, only irdy is turned off, but nothing on led display. Do i need to put ram and vga?

Is this a different post card or the same one? Try a different ISA slot.

No post codes = CPU not working. Are the jumpers configured correctly on the board? Maybe they are set to use the 486 socket?

I'm afraid, i'm out a good knowing POST cards 😀
I have 3, but i tried all of 3 in same orientation like this one. On this picture is another than on first picture.
Jumpers are al set correctly, the board worked well before this 5.25 trip to hell. They are set to onboard cpu, even though i tried to change them to socket2 cpu, and inserting intel DX2 66, but no luck.

zuldan wrote on 2025-06-29, 11:40:

butjer1010 wrote on 2025-06-29, 11:31:

So, another card, inserted right (what an idi0t i am), shows all the voltages, and clk, frame, reset also, only irdy is turned off, but nothing on led display. Do i need to put ram and vga?

Is this a different post card or the same one? Try a different ISA slot.

No post codes = CPU not working. Are the jumpers configured correctly on the board? Maybe they are set to use the 486 socket?

Only difference with all post cards, are that in other isa slots, even irdy is lit, so all the leds are on. Tried with the DX2-66mhz also, and the jumpers set for it.

Just a wild guess here…sometimes motherboards require the battery to have the proper voltage before posting. Can you try get the voltage reading of the battery by turning over the motherboard. Maybe the battery finally died.

zuldan wrote on 2025-06-29, 12:09:

Just a wild guess here…sometimes motherboards require the battery to have the proper voltage before posting. Can you try get the voltage reading of the battery by turning over the motherboard. Maybe the battery finally died.

ohohohoho, that never occurred to me!!!!! I will find pinout, and see if this is the case. If You're right, i will put Your poster on my wall 😉

Remove co-processor from socket. Re-seat (remove and put back) the BIOS ROM chip in the socket. Put some RAM into the board. Although it should output some codes even without RAM, maybe it will help. In general having RAM populated should not prevent the mobo from booting, even if the RAM is damaged (as long as it's not completly shorted).

Check all the CPU jumpers again. If the on-board CPU is not disabled properly when the 486 is added, or if it's not enabled with 486 missing, obviously the mobo will not run properly.

Putting the POST cards backwards might have routed 12V in weird places, and killed something. Hopefully not the chipset itself. But as I've said if there are no POST card codes, then you need a scope of some sort to probe around the mobo for signals. There are some cheap scopes that might work well for this task, you won't really need anything more than 40MHz, and many things around ISA bus don't go above 10MHz.