| Electronics > Repair |
| What more i can do? |
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| 222Lab_Test222:
--- Quote from: Harry_22 on November 05, 2024, 02:02:56 am ---When you described CN7 connector. Check for ISA slot. PCI was presented in 1992 --- End quote --- This is PCB CN1 here is connected to CN7 of motherboard |
| Poroit:
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 :-+ |
| 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 --- yeah i am currently doing side by side comparisons on voltages, BUT lots of ICs power are different in voltages in working and non working ones. Lets see. |
| Harry_22:
You have already checked that on working machine without EPROM IC15 and IC16 (with MS-DOS) there is a continuous beep. This means they don't have BIOS inside . Without BIOS EPROM there is no beep. That is definitely. It will be good to connect POST card to CN7. It contains all the necessary signals (ISA bus). But I'm not entirely sure we'll be able to see POST codes here. Please check the possibility to enter BIOS on the working PC. Do you have an ancient NEC PC98 keyboard? Could you also trace the beeper connection. It should be managed by the one of WACOM IC (may be indirect), which is responsible loading BIOS and support ISA bus (like south bridge). It looks like WACOM ICs are Japanese secret development of industrial chipset for Intel (under Tornado code name). One more important thing. Measure all jumpers for 3V from the battery. |
| 222Lab_Test222:
--- Quote from: Harry_22 on November 05, 2024, 05:36:42 pm ---You have already checked that on working machine without EPROM IC15 and IC16 (with MS-DOS) there is a continuous beep. This means they don't have BIOS inside . Without BIOS EPROM there is no beep. That is definitely. It will be good to connect POST card to CN7. It contains all the necessary signals (ISA bus). But I'm not entirely sure we'll be able to see POST codes here. Please check the possibility to enter BIOS on the working PC. Do you have an ancient NEC PC98 keyboard? Could you also trace the beeper connection. It should be managed by the one of WACOM IC (may be indirect), which is responsible loading BIOS and support ISA bus (like south bridge). It looks like WACOM ICs are Japanese secret development of industrial chipset for Intel (under Tornado code name). One more important thing. Measure all jumpers for 3V from the battery. --- End quote --- i dont think that CN7 can connect POST card BUT let me see. |
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