Author Topic: What more i can do?  (Read 37019 times)

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Offline Harry_22

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Re: What more i can do?
« Reply #100 on: November 09, 2024, 05:15:02 am »
Chеck the signals Chip Enable and Output Enable (please see the picture).
It would be good to compare them with the working board.

They are all good, Except there is no volatges in A pins which are input pins in Non working board, Thats the case i am mentioning from the start of this forum.

Other is everything good.

Ps
When I check where some of those pins connecetd they are connected to near tornado IC and few of them to other ICs

You have to look the signal at power on by oscilloscope.
Play with trigger function to see the beginning process.
Note: All IC15, IC16 EPROM pins are in parallel except Chip Enable#.

Track the Reset# sinal at pin 8 IC1. It should be low at the beginning and getting high if all voltages are good.
It is possible to use Reset# rising front as a trigger to see other signals at start up.

Could you attach some pictures with start up signals on Chip Enable# and Reset#
« Last Edit: November 09, 2024, 08:08:38 am by Harry_22 »
 

Offline Harry_22

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Re: What more i can do?
« Reply #101 on: November 09, 2024, 06:56:34 pm »
I'll bet a few bucks that due to increased leakage current (DCL) in capacitor C1 (after 30 years it is allowed), MB3771 chip does not release Reset# signal.
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #102 on: November 10, 2024, 11:37:20 pm »
I'll bet a few bucks that due to increased leakage current (DCL) in capacitor C1 (after 30 years it is allowed), MB3771 chip does not release Reset# signal.
IC1 8# RESET PIN
I guess it is working fine.
-Connected to IC2 1st Pin
-Connected to IC5 1st Pin
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #103 on: November 10, 2024, 11:39:31 pm »

You have to look the signal at power on by oscilloscope.
Play with trigger function to see the beginning process.
Note: All IC15, IC16 EPROM pins are in parallel except Chip Enable#.


Could you attach some pictures with start up signals on Chip Enable# and Reset#

It  seems all ok, both ic15 and 16 have similiar results.


Note : Not sure why images are being rotated automatically.
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #104 on: November 11, 2024, 12:11:34 am »
Output enable
Yellow is working board.
Blue is non working board.


The chip enable is same on working and not working board.

Note : Does the op enable pins matters as there is no input voltages to proceed.
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #105 on: November 11, 2024, 01:14:10 am »
G'day

I have emailed machine details to my contact at Komatsu so will see how that goes.

If you have equipment to assemble two controllers, you could do some side by side Comparative testing of powered up pcb's with a multimeter or oscilloscope.

I have also used Signature Analysers to compare unpowered boards.

https://huntron.com/products/trackers.htm

Harry22...great work with component ID on the motherboard :-+

Any updates.......
 

Offline Poroit

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Re: What more i can do?
« Reply #106 on: November 11, 2024, 04:10:38 am »
I emailed my contact again this morning.

I will keep at them until I get a response.

Harry_22 is doing a great job in assisting you :-+
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #107 on: November 11, 2024, 04:12:03 am »
Harry_22 is doing a great job in assisting you :-+

Wanna add more to it if you have something more, anything is ok.
 

Offline Harry_22

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Re: What more i can do?
« Reply #108 on: November 11, 2024, 05:15:23 am »
I'll bet a few bucks that due to increased leakage current (DCL) in capacitor C1 (after 30 years it is allowed), MB3771 chip does not release Reset# signal.
IC1 8# RESET PIN
I guess it is working fine.
-Connected to IC2 1st Pin
-Connected to IC5 1st Pin
Check again on pin 8. IC1
Please be more careful.
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #109 on: November 11, 2024, 05:22:40 am »

Check again on pin 8. IC1
Please be more careful.

yeah it is ok, Its high.

BUT IC23 uPD4990A , the DATA OUT pin (Pin 10) is unstable in non working board, where in working board it is constant 4.8V. I checked all the CLK, INPUTS and all are same to the working board, why is DATA OUT is not acting as it should be.

Another is IC53 74HC/HCT374, the Q0 pin (Pin 2) is low in non working board, where it is high in working board. The other are same in both working and noin working one.

Why both ICs output is weird, even when clk input and as well as enable pins are acting fine?
 

Offline Harry_22

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Re: What more i can do?
« Reply #110 on: November 11, 2024, 05:29:41 am »
Please attach pictures from oscilloscope
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #111 on: November 11, 2024, 05:34:27 am »
Please attach pictures from oscilloscope

this?
 

Offline Harry_22

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Re: What more i can do?
« Reply #112 on: November 11, 2024, 05:38:14 am »

Please be more careful.

BUT IC23 uPD4990A , the DATA OUT pin (Pin 10) is unstable in non working board, where in working board it is constant 4.8V. I checked all the CLK, INPUTS and all are same to the working board, why is DATA OUT is not acting as it should be.

Another is IC53 74HC/HCT374, the Q0 pin (Pin 2) is low in non working board, where it is high in working board. The other are same in both working and noin working one.

Why both ICs output is weird, even when clk input and as well as enable pins are acting fine?

From IC23 and IC53.
Sorry I can't imagine them from the text.
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #113 on: November 11, 2024, 05:50:53 am »

From IC23 and IC53.
Sorry I can't imagine them from the text.

Working Board
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #114 on: November 11, 2024, 05:54:12 am »

From IC23 and IC53.
Sorry I can't imagine them from the text.

Non working

Note : I am more concern to ic23 as it is op pin and connected to Wacom Ic.
 

Offline Harry_22

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Re: What more i can do?
« Reply #115 on: November 11, 2024, 06:00:29 am »
From which leg of which chip are these signals?
Please provide this information for every picture.
 

Offline Harry_22

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Re: What more i can do?
« Reply #116 on: November 11, 2024, 06:05:43 am »
Ok, seems I found this info
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #117 on: November 11, 2024, 06:10:58 am »
From which leg of which chip are thnese signals?
Please provide this information for every picture.

Its related to name in picture
ic23    its 10 pin
ic53    its 2 pin

ic23n ic53n is not working board similiar pins.
 

Offline Harry_22

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Re: What more i can do?
« Reply #118 on: November 11, 2024, 06:37:39 am »
Could you check the rest PD4990A signals.
Please set up the zero line and 1v/div scale on your scope for all measurements.
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #119 on: November 11, 2024, 07:02:28 am »
Could you check the rest PD4990A signals.
Please set up the zero line and 1v/div scale on your scope for all measurements.

These are all no working board images,
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #120 on: November 11, 2024, 07:03:17 am »
..
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #121 on: November 11, 2024, 07:04:45 am »
..
 

Offline Harry_22

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Re: What more i can do?
« Reply #122 on: November 11, 2024, 07:41:48 am »
 Ok, good, I will have a look.
For future. Move the zero line lower as on my picture. Thus you can see high level signals.
And don't forget about trigger.
 

Offline Harry_22

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Re: What more i can do?
« Reply #123 on: November 11, 2024, 09:39:23 am »
I'll bet a few bucks that due to increased leakage current (DCL) in capacitor C1 (after 30 years it is allowed), MB3771 chip does not release Reset# signal.
IC1 8# RESET PIN
I guess it is working fine.
-Connected to IC2 1st Pin
-Connected to IC5 1st Pin

Did you use a voltage divider 10:1 here?
This is the correct choice for this type of measurement, but it needs to be specified.

PS
Did I understand correctly that you measured the charge curve of 2.2uF C1 capacitor at pin 1 IC1?

PPS
No, judging by pulse rise time, this is Reset# output.
« Last Edit: November 11, 2024, 10:03:04 am by Harry_22 »
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #124 on: November 11, 2024, 10:14:19 am »
I'll bet a few bucks that due to increased leakage current (DCL) in capacitor C1 (after 30 years it is allowed), MB3771 chip does not release Reset# signal.
IC1 8# RESET PIN
I guess it is working fine.
-Connected to IC2 1st Pin
-Connected to IC5 1st Pin

Did you use a voltage divider 10:1 here?
This is the correct choice for this type of measurement, but it needs to be specified.

PS
Did I understand correctly that you measured the charge curve of 2.2uF C1 capacitor at pin 1 IC1?

PPS
No, judging by pulse rise time, this is Reset# output.

Can you clarify a bit, lots of things i do not understand
 


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