OK, I explored further, DX 33MHz doest heat up at all, DX2 66MHz (both WB and without) a bit and 50Mhz DX2 heated up quite nicely. However no POST 😒
Could it just be the BIOS that is defected?

Parni wrote on 2020-05-01, 11:11:

OK, I explored further, DX 33MHz doest heat up at all, DX2 66MHz (both WB and without) a bit and 50Mhz DX2 heated up quite nicely. However no POST 😒
Could it just be the BIOS that is defected?

OK, that's interesting.
So the board is not completely dead at least (?)
Are all 4 cpus intel?
That means at external 25MHz the cpus get warm? Did you check also the DX33 and the DX2-66 with external 25MHz? Or is one of the cpus a cyrix?
Time to double check the jumpers for cpu-type setting!

Parni wrote on 2020-05-01, 10:09:

Im wondering one thing about the manual, it's quite specific of the memory configuration regarding "Single bank" and "Dual-bank" memorys, how do I tell which one my memorys are?

The board should output some beep codes without any memory installed, you shouldn't worry about it at this point.

Double check all jumper settings (even the "reserved" ones). You also don't need CMOS battery for now, remove it.

You should double check Vcore as well (you can probe with a multimeter on the TO-220 package near the socket, thats usually the voltage reg).

CoffeeOne wrote on 2020-05-01, 11:40:

OK, that's interesting. So the board is not completely dead at least (?) Are all 4 cpus intel? That means at external 25MHz the […]
Show full quote

Parni wrote on 2020-05-01, 11:11:

OK, I explored further, DX 33MHz doest heat up at all, DX2 66MHz (both WB and without) a bit and 50Mhz DX2 heated up quite nicely. However no POST 😒
Could it just be the BIOS that is defected?

OK, that's interesting.
So the board is not completely dead at least (?)
Are all 4 cpus intel?
That means at external 25MHz the cpus get warm? Did you check also the DX33 and the DX2-66 with external 25MHz? Or is one of the cpus a cyrix?
Time to double check the jumpers for cpu-type setting!

Yes, all the CPU's are Intel, also tried with AMD 100Mhz. I didn't try with 25Mhz External, the CPU frequency selections variate a bit depending which manual look.

Manual 1 (From Total Hardware 1999 index)

Speed JP38 JP39
25MHz Open Closed
33MHz Closed Open
40MHz Open Open
50iMHz Open Closed
50MHz Closed Closed
66iMHz Closed Open
75iMHz Open Closed
80iMHz Open Open
100iMHz Closed Open

Manual 2 (scanned- assumably the original one?)

Speed JP38 JP39
25MHz Open Closed
33/66/100MHz Closed Open
50MHz Open Open
50MHz Closed Closed

When I got the DX2 50Mhz warmed up is had the JP38 and 39 closed, wonder what is the i50Mhz, does "i" stand for Intel?
With the other jumpers I have been very carefully, verified many times.

There is no multiplier jumper in this board.

computerguy08 wrote on 2020-05-01, 13:00:

The board should output some beep codes without any memory installed, you shouldn't worry about it at this point. […]
Show full quote

Parni wrote on 2020-05-01, 10:09:

Im wondering one thing about the manual, it's quite specific of the memory configuration regarding "Single bank" and "Dual-bank" memorys, how do I tell which one my memorys are?

The board should output some beep codes without any memory installed, you shouldn't worry about it at this point.

Double check all jumper settings (even the "reserved" ones). You also don't need CMOS battery for now, remove it.

You should double check Vcore as well (you can probe with a multimeter on the TO-220 package near the socket, thats usually the voltage reg).

Now we could have a breakthrough!!! 😀 The voltage regulator doesn't give any output, and also it doesn't get hot in any situation.
The regulator is model TIP31C and I measured with these instructions: https://www.wikihow.com/Test-a-Voltage-Regulator
I get in 3V but out 0V (The jumper is in 5V mode)

One thing I wonder, is this voltage regulator only for the CPU ? As I get 5V and 12V from the ISA BUS side.

Ps. I would like to check also the BIOS VCC but I cant find anywhere the 28-pin DIP chip voltage schemes?

Parni wrote on 2020-05-01, 15:54:

Yes, all the CPU's are Intel, also tried with AMD 100Mhz. I didn't try with 25Mhz External, the CPU frequency selections variate […]
Show full quote

CoffeeOne wrote on 2020-05-01, 11:40:

OK, that's interesting. So the board is not completely dead at least (?) Are all 4 cpus intel? That means at external 25MHz the […]
Show full quote

Parni wrote on 2020-05-01, 11:11:

OK, I explored further, DX 33MHz doest heat up at all, DX2 66MHz (both WB and without) a bit and 50Mhz DX2 heated up quite nicely. However no POST 😒
Could it just be the BIOS that is defected?

OK, that's interesting.
So the board is not completely dead at least (?)
Are all 4 cpus intel?
That means at external 25MHz the cpus get warm? Did you check also the DX33 and the DX2-66 with external 25MHz? Or is one of the cpus a cyrix?
Time to double check the jumpers for cpu-type setting!

Yes, all the CPU's are Intel, also tried with AMD 100Mhz. I didn't try with 25Mhz External, the CPU frequency selections variate a bit depending which manual look.

Manual 1 (From Total Hardware 1999 index)

Speed JP38 JP39
25MHz Open Closed
33MHz Closed Open
40MHz Open Open
50iMHz Open Closed
50MHz Closed Closed
66iMHz Closed Open
75iMHz Open Closed
80iMHz Open Open
100iMHz Closed Open

Manual 2 (scanned- assumably the original one?)

Speed JP38 JP39
25MHz Open Closed
33/66/100MHz Closed Open
50MHz Open Open
50MHz Closed Closed

When I got the DX2 50Mhz warmed up is had the JP38 and 39 closed, wonder what is the i50Mhz, does "i" stand for Intel?
With the other jumpers I have been very carefully, verified many times.

There is no multiplier jumper in this board.

🤣, i means internal here. So you put 50MHz to the poor DX2/50, no wonder that it heats up, it can't run at 100MHz.
But that the Intel DX 33 does not heat up at all is very suspicous.

EDIT: For the case of Intel DX33, the voltage regulator should not play a role, but maybe it does (?)

CoffeeOne wrote on 2020-05-01, 16:03:

lol, i means internal here. So you put 50MHz to the poor DX2/50, no wonder that it heats up, it can't run at 100MHz. But that th […]
Show full quote

Parni wrote on 2020-05-01, 15:54:

Yes, all the CPU's are Intel, also tried with AMD 100Mhz. I didn't try with 25Mhz External, the CPU frequency selections variate […]
Show full quote

CoffeeOne wrote on 2020-05-01, 11:40:

OK, that's interesting. So the board is not completely dead at least (?) Are all 4 cpus intel? That means at external 25MHz the […]
Show full quote

OK, that's interesting.
So the board is not completely dead at least (?)
Are all 4 cpus intel?
That means at external 25MHz the cpus get warm? Did you check also the DX33 and the DX2-66 with external 25MHz? Or is one of the cpus a cyrix?
Time to double check the jumpers for cpu-type setting!

Yes, all the CPU's are Intel, also tried with AMD 100Mhz. I didn't try with 25Mhz External, the CPU frequency selections variate a bit depending which manual look.

Manual 1 (From Total Hardware 1999 index)

Speed JP38 JP39
25MHz Open Closed
33MHz Closed Open
40MHz Open Open
50iMHz Open Closed
50MHz Closed Closed
66iMHz Closed Open
75iMHz Open Closed
80iMHz Open Open
100iMHz Closed Open

Manual 2 (scanned- assumably the original one?)

Speed JP38 JP39
25MHz Open Closed
33/66/100MHz Closed Open
50MHz Open Open
50MHz Closed Closed

When I got the DX2 50Mhz warmed up is had the JP38 and 39 closed, wonder what is the i50Mhz, does "i" stand for Intel?
With the other jumpers I have been very carefully, verified many times.

There is no multiplier jumper in this board.

🤣, i means internal here. So you put 50MHz to the poor DX2/50, no wonder that it heats up, it can't run at 100MHz.
But that the Intel DX 33 does not heat up at all is very suspicous.

EDIT: For the case of Intel DX33, the voltage regulator should not play a role, but maybe it does (?)

Shit 😁 your right about the 50Mhz, well maybe my brains&eyes starts to be tired of all this jumpering 😁

About the voltage regulator, should't i get out something with DX processor (5V) jumper selection?

Parni wrote on 2020-05-01, 16:39:

CoffeeOne wrote on 2020-05-01, 16:03:

lol, i means internal here. So you put 50MHz to the poor DX2/50, no wonder that it heats up, it can't run at 100MHz. But that th […]
Show full quote

Parni wrote on 2020-05-01, 15:54:

Yes, all the CPU's are Intel, also tried with AMD 100Mhz. I didn't try with 25Mhz External, the CPU frequency selections variate […]
Show full quote

Yes, all the CPU's are Intel, also tried with AMD 100Mhz. I didn't try with 25Mhz External, the CPU frequency selections variate a bit depending which manual look.

Manual 1 (From Total Hardware 1999 index)

Speed JP38 JP39
25MHz Open Closed
33MHz Closed Open
40MHz Open Open
50iMHz Open Closed
50MHz Closed Closed
66iMHz Closed Open
75iMHz Open Closed
80iMHz Open Open
100iMHz Closed Open

Manual 2 (scanned- assumably the original one?)

Speed JP38 JP39
25MHz Open Closed
33/66/100MHz Closed Open
50MHz Open Open
50MHz Closed Closed

When I got the DX2 50Mhz warmed up is had the JP38 and 39 closed, wonder what is the i50Mhz, does "i" stand for Intel?
With the other jumpers I have been very carefully, verified many times.

There is no multiplier jumper in this board.

🤣, i means internal here. So you put 50MHz to the poor DX2/50, no wonder that it heats up, it can't run at 100MHz.
But that the Intel DX 33 does not heat up at all is very suspicous.

EDIT: For the case of Intel DX33, the voltage regulator should not play a role, but maybe it does (?)

Shit 😁 your right about the 50Mhz, well maybe my brains&eyes starts to be tired of all this jumpering 😁

About the voltage regulator, should't i get out something with DX processor (5V) jumper selection?

I assume the voltage regulator is bypassed with the 5v jumper.

CoffeeOne wrote on 2020-05-01, 16:50:

Parni wrote on 2020-05-01, 16:39:

CoffeeOne wrote on 2020-05-01, 16:03:

🤣, i means internal here. So you put 50MHz to the poor DX2/50, no wonder that it heats up, it can't run at 100MHz.
But that the Intel DX 33 does not heat up at all is very suspicous.

EDIT: For the case of Intel DX33, the voltage regulator should not play a role, but maybe it does (?)

Shit 😁 your right about the 50Mhz, well maybe my brains&eyes starts to be tired of all this jumpering 😁

About the voltage regulator, should't i get out something with DX processor (5V) jumper selection?

I assume the voltage regulator is bypassed with the 5v jumper.

I tried with a AMD 3V processor and 3V jumper settings, I get in 0.8V and out 1,5V

Parni wrote on 2020-05-01, 17:29:

CoffeeOne wrote on 2020-05-01, 16:50:

Parni wrote on 2020-05-01, 16:39:

Shit 😁 your right about the 50Mhz, well maybe my brains&eyes starts to be tired of all this jumpering 😁

About the voltage regulator, should't i get out something with DX processor (5V) jumper selection?

I assume the voltage regulator is bypassed with the 5v jumper.

I tried with a AMD 3V processor and 3V jumper settings, I get in 0.8V and out 1,5V

Can you make a good picture of the area, where the voltage regulator resides?

TIP31C is a general purpose transistor, not a voltage regulator. We indeed need a detail picture around that area to see what circuit they are using.
https://www.st.com/resource/en/datasheet/tip31c.pdf

Parni wrote on 2020-05-01, 16:39:

About the voltage regulator, should't i get out something with DX processor (5V) jumper selection?

The voltage regulator will get bypassed in 5V mode (in this case the CPU is fed power directrly from the PSU).

It would be a good idea to probe the voltage from the CPU socket directly (when there is no CPU installed), using a solid copper wire or a needle to poke inside the socket.

CoffeeOne wrote on 2020-05-01, 18:54:

Parni wrote on 2020-05-01, 17:29:

CoffeeOne wrote on 2020-05-01, 16:50:

I assume the voltage regulator is bypassed with the 5v jumper.

I tried with a AMD 3V processor and 3V jumper settings, I get in 0.8V and out 1,5V

Can you make a good picture of the area, where the voltage regulator resides?

Here are more pictures of the CPU area.

computerguy08 wrote on 2020-05-02, 07:15:

The voltage regulator will get bypassed in 5V mode (in this case the CPU is fed power directrly from the PSU). […]
Show full quote

Parni wrote on 2020-05-01, 16:39:

About the voltage regulator, should't i get out something with DX processor (5V) jumper selection?

The voltage regulator will get bypassed in 5V mode (in this case the CPU is fed power directrly from the PSU).

It would be a good idea to probe the voltage from the CPU socket directly (when there is no CPU installed), using a solid copper wire or a needle to poke inside the socket.

I would advice you to clean that dirt from the motherboard (if you didn't do it already), given that you already removed the battery corrosion. The dirt may interfere with the chipset and/or other components.

Indeed! This could be a good idea. I can't see any GND in the picture, where should i take it in this case? (sorry, a bit n00b in these things)

evasive wrote on 2020-05-01, 20:39:

TIP31C is a general purpose transistor, not a voltage regulator. We indeed need a detail picture around that area to see what circuit they are using.
https://www.st.com/resource/en/datasheet/tip31c.pdf

OK, thanks for the info 😀 I uploaded some better pictures of the CPU area.

Parni wrote on 2020-05-02, 08:23:

Indeed! This could be a good idea. I can't see any GND in the picture, where should i take it in this case? (sorry, a bit n00b in these things)

Vss is also called GND, but you can always take ground from a HDD molex connector.

You should try to measure Vcc in both 5V and 3.3V mode and report the results here.

Once the voltages are good, you can start fiddling with jumper settings.
I have a very similar 486 board (J-403TG) with the 82C895 chipset and SC486 clock chip, you should be able to get it running after you set the jumpers properly.

(about the dirt, I got this thread confused with another one, ignore that part 😁)

Parni wrote on 2020-05-02, 08:24:

evasive wrote on 2020-05-01, 20:39:

TIP31C is a general purpose transistor, not a voltage regulator. We indeed need a detail picture around that area to see what circuit they are using.
https://www.st.com/resource/en/datasheet/tip31c.pdf

OK, thanks for the info 😀 I uploaded some better pictures of the CPU area.

I don't know, just a suggestion, measurement of the voltages makes sense as stated above.
But I would start with 5 volts first, so please use for the first tests only the good old plain Intel DX33.
I think it will work with most jumper settings, even if you configure it wrong.
But of course it needs desperately 5 volts from the power supply.
Can it be that you configured JP1 wrong?
On the picture, you have set it to 5 volts, but the picture shows a 3 volts cpu. Was that intended by you? Or did I misread it?

I think both manuals that you attached are wrong.
Go only for what is written on the mainboard!!!!

EDIT: And please, do us a favour and set a jumper on the turbo switch.
Not that the board starts working and then you wonder, why it is so slow

MORE EDIT: JP22 is wrong, too. Should be on 2-3 EDITED the MORE EDIT: Hmm the 2 manuals do not match. So forget the MORE EDIT.

CoffeeOne wrote on 2020-05-02, 10:17:

I don't know, just a suggestion, measurement of the voltages makes sense as stated above. But I would start with 5 volts first, […]
Show full quote

Parni wrote on 2020-05-02, 08:24:

evasive wrote on 2020-05-01, 20:39:

TIP31C is a general purpose transistor, not a voltage regulator. We indeed need a detail picture around that area to see what circuit they are using.
https://www.st.com/resource/en/datasheet/tip31c.pdf

OK, thanks for the info 😀 I uploaded some better pictures of the CPU area.

I don't know, just a suggestion, measurement of the voltages makes sense as stated above.
But I would start with 5 volts first, so please use for the first tests only the good old plain Intel DX33.
I think it will work with most jumper settings, even if you configure it wrong.
But of course it needs desperately 5 volts from the power supply.
Can it be that you configured JP1 wrong?
On the picture, you have set it to 5 volts, but the picture shows a 3 volts cpu. Was that intended by you? Or did I misread it?

I think both manuals that you attached are wrong.
Go only for what is written on the mainboard!!!!

EDIT: And please, do us a favour and set a jumper on the turbo switch.
Not that the board starts working and then you wonder, why it is so slow

MORE EDIT: JP22 is wrong, too. Should be on 2-3 EDITED the MORE EDIT: Hmm the 2 manuals do not match. So forget the MORE EDIT.

I am quite sure, that both manuals that you attached, do not match 100%.
So ignore it, and use as only reference the writings on the board.

CoffeeOne wrote on 2020-05-02, 11:07:

I am quite sure, that both manuals that you attached, do not match 100%.
So ignore it, and use as only reference the writings on the board.

The second manual seems to match his board, what makes you think it doesn't?

All jumpers seem to be in the same position and markings as in the manual.

computerguy08 wrote on 2020-05-02, 11:31:

CoffeeOne wrote on 2020-05-02, 11:07:

I am quite sure, that both manuals that you attached, do not match 100%.
So ignore it, and use as only reference the writings on the board.

The second manual seems to match his board, what makes you think it doesn't?

All jumpers seem to be in the same position and markings as in the manual.

True, it's really confusing:
On the board and in the second manual, there is the block (from up to down):
JP27
JP3
JP22
JP8
JP5

But in the figure of the first manual:
it is
JP27
JP3
JP22
JP5
JP8

so the 2nd manual seems to be good, you are right.

AND there is a table on the board with the settings for
JP3, JP5, JP8

so not in the order as the jumpers are on the board, moreover JP22 is in between. Oh my god.
That does not make it more easy.

About JP1, that's the maybe most important one.
It should be either closed or open.

But there seems another empy pin beside it. ???? What it is?