| Electronics > Repair |
| What more i can do? |
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| 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:
--- Quote from: Poroit on November 14, 2024, 06:33:55 am --- It seems to me that you want him to focus on the D4990A. --- End quote --- 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:
--- Quote from: Poroit on November 14, 2024, 06:33:55 am ---BTW My contact a Komatsu Australia can not find any details on these machines ever been brought into Australia. --- End quote --- Maybe it is only in JAPAN, or could be in TAIWAN And CHINA too. BUT not sure. |
| Harry_22:
--- Quote from: 222Lab_Test222 on November 14, 2024, 04:18:38 am ---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. --- End quote --- 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 |
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