| Electronics > Repair |
| What more i can do? |
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| 222Lab_Test222:
Its a 30 years old PCB board and the company stopped making it, so no datasheet and no schematic. It's a hard troubleshooting, the main issues is beeping continuously, after the hard time watching all ICs and stuffs, still couldn't figure out where the problem is.This is a machine controller which is used to dig underground for sewage repair system. I have lots of those boards with 99% having the error of beep. The beep is continuous beep and no break on between. I checked all capacitor, no sign of sort, the IC looking good, no burn marks as well as any damages. The SRAM, Flash seems ok as i used that from the working board, MSDOS is good as i used that also from working board. Where am i wrong? What more to do? |
| 222Lab_Test222:
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| Harry_22:
Hi! If you have 99% of the same faulty boards, it may mean that the external equipment/power supply is also faulty please don't forget it. But most likely some element has changed its parameters over time. Electrolytes are very suitable for this role, although early caps are less susceptible to "capacitor plague". And you have very few of them there. The chips are definitely working. Has the battery finally run out and the BIOS jammed? PS Is it possible to connect a monitor to it? |
| Sorama:
the only issue is that it beeps constantly (but works apart from that) , or are there other issues? |
| Phil1977:
Is there any fan in the system? Some embedded system mainboards continuously beep if they register some operation parameters are out of tolerance. Values worth to check are - Fan speed - Bus voltages - CPU voltages (AFAIK the Intel 486DX2-66 generally is a 5V-type. But I´d check if there are any 3.3V-parts on the board) - Battery voltage |
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