What more i can do?

[Poroit]

Please clarify which Model Iron mole you have as there are numerous models shown online.

[222Lab_Test222]

Please clarify which Model Iron mole you have as there are numerous models shown online.

It doesnt matter because every Iron Mole has a Motherboard inside it, And 1 Motherboard controller can be used for multiple models.
If you need a specific one then TP95S-2.

The Picture Explanation
Red Lines : The things I circle with red lines is the controller box, Inside it there is a motherboard which we are diagnosing now and trying to figure out the issues going on it. We can see the control panel the buttons as well as screen.

Yellow Lines : After the screen is turn on and everything is ok, this is the program used for tunnelling the ground and many more options, which i do not have much knowledge.

[Harry_22]

If the green LED is neither bright nor dim, it means it is monitoring some CLK pulses.
How does it glow on a non-working board?

It Sometimes glow so bright or sometimes the lED is not turn on.

Most likely this is CLK signal for ISA or another one.
Check and compare the signals on Clock/Data chip. Start from CLK pin

[Harry_22]

Use the same method.The first channel at Reset# pin 8 MB3771 as a trigger. One power up - one trace.

[222Lab_Test222]

Most likely this is CLK signal for ISA or another one.
Check and compare the signals on Clock/Data chip. Start from CLK pin

Which IC CLK pin you are referring to?
Or you referring to the CLK of Oscillators.

[Harry_22]

Most likely this is CLK signal for ISA or another one.
Check and compare the signals on Clock/Data chip. Start from CLK pin

Which IC CLK pin you are referring to?
Or you referring to the CLK of Oscillators.

It is here (blue circle).

[Harry_22]

Do the following for me.
On the working board press your finger against the 66 MHz crystal pins. Then turn it on and listen for beep.
If it doesn't help, lightly wet your finger and try again.

I Tried, Even when i didn't press, its a one tone beep always on starting of motherboard.

After I pressed, I did not see any changes, I used alcohol as well BUT its same beep, not a different one.

Just noticed.
It looks like you tried it on non-working machine, although I asked you to slobber on a finger (sorry if I expressed myself incorrectly)  and press it against the quartz legs on working machine.
Let's try again.

And don't forget to take pictures for CLK as described above.

[222Lab_Test222]

It is here (blue circle).

First image CLK PIN
Both Non Working and Working Board have that same Picture.

Second Image DATA IN PIN
Both Non working and working have same picture.

Third Image is CS PIN

Note : The CLK and DATA IN PIN have similiar images, i tried couple of times if there is an error BUT its same.

[222Lab_Test222]

Just noticed.
It looks like you tried it on non-working machine, although I asked you to slobber on a finger (sorry if I expressed myself incorrectly)  and press it against the quartz legs on working machine.
Let's try again.

I did try on the working board, and still result same. I did not see any changes although i press it hard. I also slobber on my finger, also used alchol nope, same results.

[Harry_22]

This is Picture of CPU CLOCK and RESET PIN.
The working board and non working board is same.

1st is CLOCK  and 2nd is RESET.

I don’t understand at what points you looked at these curves?

[222Lab_Test222]

This is Picture of CPU CLOCK and RESET PIN.
The working board and non working board is same.

1st is CLOCK  and 2nd is RESET.

I don’t understand at what points you looked at these curves?

Jus checking whether CPU is behaving as it should be or not.

[Harry_22]

Here?

[222Lab_Test222]

Here?

Yeah I checked RESET and CLK pin.

[Harry_22]

Here?

Yeah I checked RESET and CLK pin.

Where did you find them, on the bottom PCB layer?

[222Lab_Test222]

Where did you find them, on the bottom PCB layer?

From DATASHEET
In board, its on back side..

[222Lab_Test222]

Everything is good BUT Look that E15 HOLD PIN.
1st Pic is Not Working.
2nd Pic is Working.

[Poroit]

G'day Harry_22,

Is the OP focusing on the correct points for the signals you need to see?

It seems to me that you want him to focus on the D4990A.

I see there is a Test Pont near that IC.

BTW
My contact a Komatsu Australia can not find any details on these machines ever been brought into Australia.

[222Lab_Test222]

It seems to me that you want him to focus on the D4990A.

The RTC D4990A Is not performing as it should be, Everything is fine except Output. The output should be constant HIGH But It keeps fluctuating between HIGH and LOW.

[222Lab_Test222]

BTW
My contact a Komatsu Australia can not find any details on these machines ever been brought into Australia.

Maybe it is only in JAPAN, or could be in TAIWAN And CHINA too. BUT not sure.

[Harry_22]

This is Picture of CPU CLOCK and RESET PIN.
The working board and non working board is same.

1st is CLOCK  and 2nd is RESET.

Well done and going in the right direction!
But the CLK and Reset# signals must be present on the working board. Check the pinout.

 You will find here the Databook on 486DX2 processor
https://bitsavers.trailing-edge.com/components/intel/80486/Intel486_DX2_Microprocessor_Data_Book_Jul92.pdf

[Harry_22]

G'day Harry_22,

Is the OP focusing on the correct points for the signals you need to see?

It seems to me that you want him to focus on the D4990A.

I see there is a Test Pont near that IC.

BTW
My contact a Komatsu Australia can not find any details on these machines ever been brought into Australia.

Hi Poroit!

We focused on Calendar/Clock D4990A becase it it easy accesseble and have clear pinout. But we don't see the activity becase we observe only 600ms after Reset# release. I guess this TP is for RTC quartz frequency adjustment via C10.

The malfunction occurse immediately after Reset.

[222Lab_Test222]

This is Picture of CPU CLOCK and RESET PIN.
The working board and non working board is same.

1st is CLOCK  and 2nd is RESET.

Well done and going in the right direction!
But the CLK and Reset# signals must be present on the working board. Check the pinout.

 You will find here the Databook on 486DX2 processor
https://bitsavers.trailing-edge.com/components/intel/80486/Intel486_DX2_Microprocessor_Data_Book_Jul92.pdf

Its same i ,mean Both working board as well as non working board have same result thats what i am saying.

Did you check that PIN E 15 HOLD, thats only different in working and non working one.

[Harry_22]

This is Picture of CPU CLOCK and RESET PIN.
The working board and non working board is same.

1st is CLOCK  and 2nd is RESET.

Well done and going in the right direction!
But the CLK and Reset# signals must be present on the working board. Check the pinout.

 You will find here the Databook on 486DX2 processor
https://bitsavers.trailing-edge.com/components/intel/80486/Intel486_DX2_Microprocessor_Data_Book_Jul92.pdf

Its same i ,mean Both working board as well as non working board have same result thats what i am saying.

Did you check that PIN E 15 HOLD, thats only different in working and non working one.

Regarding HOLD I found interesting information:
"The Intel486 DX2 microprocessor recognizes and
can respond to HOLD, AHOLD, and BOFF # requests
regardless of the state of RESET. Thus, even
though the processor is in reset, it can still float its
bus in response to any of these requests."

But please focuse on CLK and Reset. The signals must be on working board.

[222Lab_Test222]

But please focuse on CLK and Reset. The signals must be on working board.

Let me check again,

By the way i am using this PDF for CPU.
https://datasheets.chipdb.org/Intel/x86/486/datashts/27277002.PDF

[Harry_22]

Ring the Reset signal from CPU to D1 Power supply monitor. It passes via some 74... logic

Also ring the path of CLK CPU signal.
Draw the scheme or mark them on the top PCB layer picture.

PS
Sorry I have to go run.