| Electronics > Repair |
| What more i can do? |
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| 222Lab_Test222:
--- Quote from: Poroit on November 05, 2024, 03:35:57 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 :-+ --- End quote --- Any updates....... |
| Poroit:
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 :-+ |
| 222Lab_Test222:
--- Quote from: Poroit on November 11, 2024, 04:10:38 am ---Harry_22 is doing a great job in assisting you :-+ --- End quote --- Wanna add more to it if you have something more, anything is ok. |
| Harry_22:
--- Quote from: 222Lab_Test222 on November 10, 2024, 11:37:20 pm --- --- Quote from: Harry_22 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. --- End quote --- IC1 8# RESET PIN I guess it is working fine. -Connected to IC2 1st Pin -Connected to IC5 1st Pin --- End quote --- Check again on pin 8. IC1 Please be more careful. |
| 222Lab_Test222:
--- Quote from: Harry_22 on November 11, 2024, 05:15:23 am --- Check again on pin 8. IC1 Please be more careful. --- End quote --- 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? |
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