KRC1 dead motherboard complite black screen

Hi .

Iam currently facing some problems about KUKA KRC1. Here is the details.

The robot of mine was not on duty for about a few years. Then suddenly my manager decided to use this on our company work so i got the duty. The employees before me , has been dismounted the motherboard with all other cards (dse,vga) and placed somewhere safe. So my first job was to install all cards together. The cards has been installed somewhere dry and dustfree using pvc gloves. The motherboard's battery was complitely removed by old employee so i think memory lost may accoured.

When i installed all cards and then power the robot cabinet , teachpendant screen doesnt display anything no BIOS no bright no shine etc. So i thought maybe its because of the KCP itself but i have replaced our other krc1 device and it worked. I have also tried both vga and dse card with a working robot and those are good too. Then i have changed step by step dse and vga card slots because of maybe damaged slots but no luck either. Then i have removed KUKA VGA card and placed a standart VGA card to the AGP slot but there is no display from external monitor also. The external monitor is from my office monitor so i m sure it is working. Then i have removed the motherboard again and i have changed all bulk electrolytic capacitors with a new ones also still no display at all. I have checked all removed capacitors using LRC meter, none of them was damaged and they were quite good quality ones which is now hard to find in my country I have also checked the voltage from the AT power supply those seems correct both 12V and 5V buses are good when i power up the krc1 cabinet. When power applied throught the cabinet DSE board's led shines. Then i suspect the RAM modules and i have replaced with other 3 ram device still no luck.

At the total , i think motherboard damaged. I have experiance about electronic but dont know where to start and which part may damaged so im here to ask you guys. Hope we can find an answer for black screen error and it will lead anyone who read this thread.

Quote from DannyDJ

Did you tried to short PWR_ON jumpers on the motherboard? When CMOS battery is dead, the BIOS settings are set to default and the motherboard does not turn on it's own when you turn on power switch on the cabinet. One has to force it by shorting PWR_ON jumpers, then go to BIOS and choose KUKA settings afterwards.

Hi.

Thank you for respons .

Today i finally had the spare time for try that and unfortunatly that doesnt worked also.

According to the manual of motherboard, this power headers are for AT Power supply on/off operation. My AT is working when the cabinet energised because ,as i told before , i can measure 12v and 5v from output of the power supply. Also i can hear the harddrive spinning. I think this means somewhere inside the motherboard is dead. But the question is where exactly ?

Quote

Well, I think you've exhausted all the obvious options (and a few more). About the only thing I can think of, aside from replacing the motherboard, is to try obtaining a POST test device and seeing if it generates any results.

A long-shot option would be to find a regular PC motherboard of the same vintage, and try transferring the DSE, KVGA, RAM, HDD, etc onto that. I haven't touched a KRC1 in over 20 years, but I think the motherboard wasn't customized for KUKA, it was "just" a standard PC motherboard but built to industrial-grade standards.

Thanks. A post device can help. Rather than buy a post device new vintage motherboard easy to find , i think. Will try to look for.

But if there is someone who ever solved this problem can tell how to repair here. And it would be great to know that just in case for future problems