Electronics > Repair
What more i can do?
222Lab_Test222:
--- Quote from: Poroit on November 04, 2024, 05:14:57 am ---I like your tenacity :)
What is the model number of your Komatsu Tunneling machine?
I have a contact at Komatsu who may be able to assist with a circuit drawing?
Have you contacted Komatsu in Japan?
Do you have enough boards and peripherals to make up two full systems for powered up side by side comparative testing?
--- End quote ---
These images are the machines.
even i contact them they wont reply to the individual request i guess.
Yes i have few boards and system that can run for comparative testing.
For comparative testing the screen need to show up, this keep beeing i am not sure how i can comapre them. BUT yeah i have full systems to compare.
u666sa:
--- Quote from: 222Lab_Test222 on November 03, 2024, 11:06:39 pm ---Let me see, And where to inject voltage i mean, when i cross check working and non working board in terms of voltage, i found lots of volatges diffenrce in more than 10 ICs, Where is main trouble hard to conclude.
--- End quote ---
Your board has power rails. 5 volts, 3 volts, perhaps other volts number. Volts come out of power supplies, either on board on off board. Each chip has datasheet which requires certain voltage to operate. You can check these voltages.
Also, you can check resistance to ground on power rails and since you have a known good board, you know what that resistance should be.
Realistically, going into logic of chips is beyond your scope or abilities. All you can do is check power rails, resistances of power rails, find bad solder, find bad caps. If there is a short or a partial short (soft short) find that short and replace faulty component. This one goes to where to inject voltage, you have to look at resistances first. (you inject less than 1 volt, 0.3 - 0.7 volts)
How did you check your caps? You should take out all caps and check them using LCR meter at different frequencies. Your new board has same caps as your old broken board, so this leads me to ask this question. How did you check your caps and with what?
On these pictures, all caps have to be desoldered and checked with LCR meter.
Then, you take an oscilloscope, one of those rare times when you actually need an oscilloscope. Measure clock at every one of these crystals. Clock should be same as on working board.
Once you know all your caps are good and once you measured clock. You check the power rails. Check the voltages. Then check resistances. At this point you basically looking for shorts.
No bad solder?
Caps are good?
Clocks are good?
Voltages are good?
No shorts?
Check BIOS. There is BIOS chip itself. Plus there could be some programmable controllers, so you have to check datasheet for each chip on there, and if it is programmable, that could be it.
At this point, assuming you did the basic stuff like checking memory, and you scanned your board under microscope for bad solder, including all the connectors, bad pins, water damage, etc.. It's logic. Nothing you can do.
222Lab_Test222:
--- Quote from: u666sa on November 04, 2024, 06:31:01 am ---
--- Quote from: 222Lab_Test222 on November 03, 2024, 11:06:39 pm ---Let me see, And where to inject voltage i mean, when i cross check working and non working board in terms of voltage, i found lots of volatges diffenrce in more than 10 ICs, Where is main trouble hard to conclude.
--- End quote ---
Your board has power rails. 5 volts, 3 volts, perhaps other volts number. Volts come out of power supplies, either on board on off board. Each chip has datasheet which requires certain voltage to operate. You can check these voltages.
Also, you can check resistance to ground on power rails and since you have a known good board, you know what that resistance should be.
Realistically, going into logic of chips is beyond your scope or abilities. All you can do is check power rails, resistances of power rails, find bad solder, find bad caps. If there is a short or a partial short (soft short) find that short and replace faulty component. This one goes to where to inject voltage, you have to look at resistances first. (you inject less than 1 volt, 0.3 - 0.7 volts)
How did you check your caps? You should take out all caps and check them using LCR meter at different frequencies. Your new board has same caps as your old broken board, so this leads me to ask this question. How did you check your caps and with what?
On these pictures, all caps have to be desoldered and checked with LCR meter.
(Attachment Link) (Attachment Link)
Then, you take an oscilloscope, one of those rare times when you actually need an oscilloscope. Measure clock at every one of these crystals. Clock should be same as on working board.
Once you know all your caps are good and once you measured clock. You check the power rails. Check the voltages. Then check resistances. At this point you basically looking for shorts.
No bad solder?
Caps are good?
Clocks are good?
Voltages are good?
No shorts?
Check BIOS. There is BIOS chip itself. Plus there could be some programmable controllers, so you have to check datasheet for each chip on there, and if it is programmable, that could be it.
At this point, assuming you did the basic stuff like checking memory, and you scanned your board under microscope for bad solder, including all the connectors, bad pins, water damage, etc.. It's logic. Nothing you can do.
--- End quote ---
I can relate everything you said and done everything from start, I spend like 1 month on it already.
the only thing is that I did not found any datasheet of WACOM ICs, i search everywhere and still nope.
Things like RAM, BIOS all are good, only problem is pin of BIOS as it is not receving power. Thats the main concern for now.
u666sa:
--- Quote from: 222Lab_Test222 on November 04, 2024, 06:42:25 am ---the only thing is that I did not found any datasheet of WACOM ICs, i search everywhere and still nope.
--- End quote ---
Those 3 WACOM chips look like they are programmable. You could perhaps swap all 3 from working board. If you going to do this, I would attack this using low melt solder, and then heat from the bottom.
--- Quote from: 222Lab_Test222 on November 04, 2024, 06:42:25 am ---only problem is pin of BIOS as it is not receving power. Thats the main concern for now.
--- End quote ---
You can cut trace so it only goes to that BIOS pin. Give it power using lab PSU. But, if one of those WACOM chips turns on BIOS, that could be your problem.
222Lab_Test222:
--- Quote from: u666sa on November 04, 2024, 07:04:52 am ---
--- Quote from: 222Lab_Test222 on November 04, 2024, 06:42:25 am ---the only thing is that I did not found any datasheet of WACOM ICs, i search everywhere and still nope.
--- End quote ---
Those 3 WACOM chips look like they are programmable. You could perhaps swap all 3 from working board. If you going to do this, I would attack this using low melt solder, and then heat from the bottom.
--- Quote from: 222Lab_Test222 on November 04, 2024, 06:42:25 am ---only problem is pin of BIOS as it is not receving power. Thats the main concern for now.
--- End quote ---
You can cut trace so it only goes to that BIOS pin. Give it power using lab PSU. But, if one of those WACOM chips turns on BIOS, that could be your problem.
--- End quote ---
Can you explain a bit how to do that cut trace one,
It has 208 pin IC, i am not sure if i am able to desolder it,
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