This is an excellent video! I'm fixing a CNC machine control board with this microprocessor and other chips. Very helpful. In my case, a bad opto buffer chip was preventing the "start" signal for a analog to digital converter. I diagnosed the problem with an oscilloscope exactly as you have in the video.
This was a great video. I am repairing a dead Solartron 7081 DVM and it uses old 80's microprocessor. I'm having difficulty know where to start with the logic troubleshooting. All the power rails are clean. You video has helped me understand how I can start interpreting the hi/lo signals on the pins.
Thanks for the video. Is there a chart I can use to know what my signal should look like if things are working fine? The MPU has many pins with many different signals based on what the pins taking in as input or outputting. I want to know what type of output/input looks like what.
Hi, You are very welcome, In fact the datasheet of the ic will show the timing digram of some output related to the other outputs for example the clock signal cycles rise edge or folling edge plotted against the read and write signals and showing the moment when the data or address should be available, it is very interesting to analizer the signals using multiple channels to cupture the trigger of failure, but also to tell the truth that is not very practical with now days complex 32 bits or 64 bits systems without using advance Data analyzers.
Hi, Yes you are right this aplacable to that, those days microprocessor circuits were more straightforward to trace and troubleshoot, but I found this approach as principle is still helpful to check the modern circuit.
@@saudautomation Yes, I am agreeing, this is a very useful video 100% . However what is so great about this video is that a lot of old Japanese Synths like Roland , Korg and Yamaha, use similar components. So for synthesizer repairs, this video is exactly what one has to do. Look at Roland JX-3P, the CPU is intel 8051 very similar, all parts except CPU are made in Japan just like your board. Thank you for making this video!!
@@saudautomation can I ask you the make and model of the probe you are using - also what is the box it is connected to that is then connected to the BNC connector on the Tektronix Oscilloscope?
In fact the probe with the little box is coming as one set this is P6201 (FET) active probe, this one is very helpful in minimizing loading the circuit under test with higher input resistance, it improves also frequency respond of the osoloscop. This works with few series models of Tek osoloscops as it required power supply port to be available for example Tek 485.
Very nice. What I'm looking for is how to bypass output of an SAK C167CR-LM chip, as "drive away " protection is not needed by me...and I've removed the several modules that have been designed to stop the ECU from working if there's an issue. I'm guessing that by applying the proper output, from this IC, my poor car will run again after 7 years of death. Lol. Could you advise where a schematic can be found for this chip? Thanks so much...)
Hello Saud - How can I repair a N76E003 microcontroller with a short from Vdd to ground? I can't just replace it with an off the shelf mc, because it has secret proprietary sofware on it.
+The Kaiser Hello The Kaiser. You need to identify the cause of shot, it is not necessary the short is in the microcontrollr as long it is installed on circuit board it can be from other components as well. N76E003 it has one VDD and one GND input pin, therefore the easier way just lift the VDD pin from the PCB by solder iron ,to isolate it from the copper track . 1- now check the continuity between the copper track under the pin to the ground if short circuit, then this cased by other component on the board so just Trace it back it can be from the voltage regulator circuit, diode or filter capacitor etc. 2- Check the continuity from removed VDD pin to the ground if short exist then most likely is caused by microcontrollr, now remove the microcontrollr from the board to eliminate the possibility this caused by the GPIO of microcontrollr, and test the continuity between VDD and GND pin while the microcontrollr outside the circuit, if short circuit then no much hop the IC is defective. But If no short and and you need to try run it then install back the microcontrollr but keep all the GPIO pint isolated then connect them one by one to catch the one causing the problem.
Hello Saud - Thank you for your quick reply. I removed the N76E003 microcontroller completely from the circuit board, tested it on its own and it has a short from Vdd to ground. How can I repair it?
+The Kaiser Hello. In this case we are like the soldier who lost his last bullet, this indicates the silicon die has internal short and no much can be done to save it, I fully understand your need to get this works because of some reason, this happens to me some time when we don't have much choice.
Damn. I hate to have no bullets! Isn't there a reset or something? Or one could expose the die and fix the doted barrier? Or one could try to extract the proprietary software and put it on a virgin chip? However. You have a very good channel. Carry on. Greetings to Oman? from Germany.
Please help us learn the iPhone X circuitry, there is a guy that has a store and does iPhone repair (Rossman) but he doesnt use oscilloscope. He mostly checks with a multimeter and replaces components based on incorrect readings from it.
Hi thanks for feedback. Yes ther are other different techniques in troubleshooting, with cell phones circuit boards there is no much options to probe the signals as many IC's are BGA type, therefore the experience plus knowing the function of IC will help in predicting the faulty part and replace some time.
Where did you get that controller? It looks like something from the 80's. I designed and implemented embedded systems back then with 8085, z80, 6502, etc. Wow... memory lane!
Hi thanks for watching, That's right this board belongs to PLC programming device from end 80's to early 90, the device was dismentaled I just saved the board. Yes the earlier processes were very interesting to learn and troubleshoot compare to now getting so complex.
@@saudautomation I agree - I'm glad I learned back when each of the parts were separate ICs, now everything is on a single SoC IC, which is still fun, but other reasons. Great video, thanks!
![[Full] 4 ต่อ 4 Celebrity EP.922 | 10 พ.ย. 67 | one31](http://i.ytimg.com/vi/zmV5HRIxIBI/mqdefault.jpg)
Absolutely excellent step by step process for a very practical use of the oscilloscope. Very helpful and systematic presentation. Thank you.
You are very welcome, thanks for positive feedback.
This is an excellent video! I'm fixing a CNC machine control board with this microprocessor and other chips. Very helpful. In my case, a bad opto buffer chip was preventing the "start" signal for a analog to digital converter. I diagnosed the problem with an oscilloscope exactly as you have in the video.
+Wes Johnson
Well done. Thanks
Great video on MPUs. Good for troubleshooting Test equiptment (80's and 90's) faults that aren't on the analog side of things.
This was a great video. I am repairing a dead Solartron 7081 DVM and it uses old 80's microprocessor. I'm having difficulty know where to start with the logic troubleshooting. All the power rails are clean. You video has helped me understand how I can start interpreting the hi/lo signals on the pins.
Great news, thanks for feedback. 👍
really usefull video. great explanation.
tks a lot for all these valuable informations ⚘⚘
Most welcome 👍
انت متخصص و فاضل یا حبیبی. افضل منک لا اوجدته. شکرا جزیلا. 🙏🙏
العفو.
هذا بفضل أخلاقك الطيبة. شكرا على المتابعة و حياك الله.
Great explanatory video!
This is such a useful video, thank you!
Thank you as well for good feedback.
Thanks for the video. Is there a chart I can use to know what my signal should look like if things are working fine? The MPU has many pins with many different signals based on what the pins taking in as input or outputting. I want to know what type of output/input looks like what.
Hi, You are very welcome,
In fact the datasheet of the ic will show the timing digram of some output related to the other outputs for example the clock signal cycles rise edge or folling edge plotted against the read and write signals and showing the moment when the data or address should be available, it is very interesting to analizer the signals using multiple channels to cupture the trigger of failure, but also to tell the truth that is not very practical with now days complex 32 bits or 64 bits systems without using advance Data analyzers.
@@saudautomation Thanks for the response. I wanted to know that to work on an old Commodore 64 with much simpler system.
Much Appreciated!!! Enjoyable video
Thanks 👍
Great video! Thanks for sharing.
Thanks 👍
You basically described how to troubleshoot the digital part of 99% of 1980's Synthesizers #vintagesynthrepair
Hi,
Yes you are right this aplacable to that, those days microprocessor circuits were more straightforward to trace and troubleshoot, but I found this approach as principle is still helpful to check the modern circuit.
@@saudautomation Yes, I am agreeing, this is a very useful video 100% . However what is so great about this video is that a lot of old Japanese Synths like Roland , Korg and Yamaha, use similar components. So for synthesizer repairs, this video is exactly what one has to do. Look at Roland JX-3P, the CPU is intel 8051 very similar, all parts except CPU are made in Japan just like your board.
Thank you for making this video!!
Many thanks for you as well, this is a great and positive feedback from your side.
@@saudautomation can I ask you the make and model of the probe you are using - also what is the box it is connected to that is then connected to the BNC connector on the Tektronix Oscilloscope?
In fact the probe with the little box is coming as one set this is P6201 (FET) active probe, this one is very helpful in minimizing loading the circuit under test with higher input resistance, it improves also frequency respond of the osoloscop.
This works with few series models of Tek osoloscops as it required power supply port to be available for example Tek 485.
Well done brother , keep it up, great staff...
Thanks brother, I value your feedback.
Very nice. What I'm looking for is how to bypass output of an SAK C167CR-LM chip, as "drive away " protection is not needed by me...and I've removed the several modules that have been designed to stop the ECU from working if there's an issue. I'm guessing that by applying the proper output, from this IC, my poor car will run again after 7 years of death. Lol. Could you advise where a schematic can be found for this chip? Thanks so much...)
I found full datasheet fo C167CR microcontroller is available at (alldatasheet) web site please search.
@@saudautomation THANK YOU so much, my friend!!! I'll look...)
Hello Saud - How can I repair a N76E003 microcontroller with a short from Vdd to ground?
I can't just replace it with an off the shelf mc, because it has secret proprietary sofware on it.
+The Kaiser
Hello The Kaiser.
You need to identify the cause of shot, it is not necessary the short is in the microcontrollr as long it is installed on circuit board it can be from other components as well.
N76E003 it has one VDD and one GND input pin, therefore the easier way just lift the VDD pin from the PCB by solder iron ,to isolate it from the copper track .
1- now check the continuity between the copper track under the pin to the ground if short circuit, then this cased by other component on the board so just Trace it back it can be from the voltage regulator circuit, diode or filter capacitor etc.
2- Check the continuity from removed VDD pin to the ground if short exist then most likely is caused by microcontrollr, now remove the microcontrollr from the board to eliminate the possibility this caused by the GPIO of microcontrollr, and test the continuity between VDD and GND pin while the microcontrollr outside the circuit,
if short circuit then no much hop the IC is defective. But If no short and and you need to try run it then install back the microcontrollr but keep all the GPIO pint isolated then connect them one by one to catch the one causing the problem.
Hello Saud - Thank you for your quick reply.
I removed the N76E003 microcontroller completely from the circuit board, tested it on its own and it has a short from Vdd to ground.
How can I repair it?
+The Kaiser Hello.
In this case we are like the soldier who lost his last bullet, this indicates the silicon die has internal short and no much can be done to save it, I fully understand your need to get this works because of some reason, this happens to me some time when we don't have much choice.
Damn. I hate to have no bullets! Isn't there a reset or something?
Or one could expose the die and fix the doted barrier? Or one could try to extract the proprietary software and put it on a virgin chip?
However. You have a very good channel. Carry on. Greetings to Oman? from Germany.
+The Kaiser
👍 Greetings to Germany from Oman.
Brother the long strip like IC in right of RAM. What is that component? Please reply brother.
Hi,
It is 10k resistor network.
@@saudautomation thanks brother 🤝
👍
hello u are amaizing on electronics, plz some more videos on such kind of analysis plz. specifically on music instrument like piano. on my request plz
Hello, you are very welcome,
I will try my best.
Please help us learn the iPhone X circuitry, there is a guy that has a store and does iPhone repair (Rossman) but he doesnt use oscilloscope. He mostly checks with a multimeter and replaces components based on incorrect readings from it.
Hi thanks for feedback.
Yes ther are other different techniques in troubleshooting, with cell phones circuit boards there is no much options to probe the signals as many IC's are BGA type, therefore the experience plus knowing the function of IC will help in predicting the faulty part and replace some time.
Where did you get that controller? It looks like something from the 80's. I designed and implemented embedded systems back then with 8085, z80, 6502, etc. Wow... memory lane!
Hi thanks for watching,
That's right this board belongs to PLC programming device from end 80's to early 90, the device was dismentaled I just saved the board.
Yes the earlier processes were very interesting to learn and troubleshoot compare to now getting so complex.
@@saudautomation I agree - I'm glad I learned back when each of the parts were separate ICs, now everything is on a single SoC IC, which is still fun, but other reasons. Great video, thanks!
👍👍
👍😎
Thank you!
You are very welcome 👍
nice explanation
+anis mahmud
Thanks👍
Nice Video on the 8085, maybe you can do one on the 6800 mpu
+p
👍
...or 6502, or z80?
U are mechatronic graduate sir
Hi, and thanks for watching
I am Instrumentation and control graduate.
Stop touching the EPROM...jeez
Dear friend, first of all many thanks for your valid feedback, yes maybe I need to improve the way I present. 👍
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