Dear Sir, I would like to ask for your help, yesterday my hook kr 230 comp, turned on and off as normally as every time. However, this morning when I turned it on, the screen was black and did not show any image. After a couple of attempts to turn it on, I managed to turn it on, but when I turn it on, another window appears from the BIOS with something written on it (another window that opens when turning on and before starting Windows. I'm sending you a link where you can watch the process of turning on the robot. https://files.fm/f/8au9m3kjs6
Problem power on robot
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Uros Marinkovic -
December 24, 2023 at 3:17 PM -
Thread is Unresolved
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MOM
December 24, 2023 at 4:22 PM Approved the thread. -
Normally I don't follow external links, but it's Christmas Day
Can't see any abnormal behavior for the first seconds of booting a KRC2.
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ok, but then why is my screen black during several starts
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well you need to troubleshoot and find out what exact part is having issue.
first you need to think about everything that is involved in displaying image:
1. KPC needs power. check without power it does not boot and there is no image. did you check if there is a loose connection somewhere in the power line etc. could be wiring to KPC (X961 if i recall) or the KPC power supply.
2. Image is generated by a video card. this card may be seated incorrectly in its slot. slight vibration may make it work or not work. if there could be defective card, having hard time starting or it is experiencing thermal fault. thermal fault is experienced with temperature changes. most materials shrink when cooled and expand when heated. so if there is a crack in some of connections (internal to some IC or PCB etc) then connection may be broken initially but after some time (perhaps few reboots) the components may warm up enough to expand and make contact. after that circuit may work temporarily. this type of failure is best identified by hot air and cold spray. warning, this is not for everyone to play with. KVGA is extremely sensitive to ESD and any friction could be deadly since it builds static charge yes that can be done by any movement.... like moving air {due to hot air gun or spray) or touching hand or putting board into a bag, or pushing it across desk...
3. card is seated in a motherboard slot. those slots have many connections, it is enough for one of them to be contaminated or oxidized. this is why reseating board can help - it can bypass or resurface/scrape oxidized spot. there are also contact sprays but one need to choose carefully since last thing you want is to introduce contaminants in forms of dust or spray residue. motherboard may also have other defects. for example bulging capacitors, dried out capacitors, thermal faults, etc.
4. video data is transferred by cable/wires to KCP. cables can have aby of mentioned defects. moving cables are specially likely to have problem like broken wire. this includes connections that are internal to the cabinet.
5. the LCD display is passive. it does not emit light. to see image it requires background light that passes through display. but if the source of this background light is not working, there is no image. so check if light gets power. like before it may be a poor connection and even response to moving/shaking.
the usual approach is to try swapping parts. the easiest thing to try fist is the teach pendant. if the problem persists, you know that problem is inside the cabinet. next try swapping KPC. if that does not help, problem is internal cabinet wiring. if this fixes the problem, then defect is inside removed KPC. working inside KPC is best left to professionals since ESD can cause further damage. this would involve trying to reseat KVGA or replace it. possibly also replace PSU or motherboard.
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and i took liberty of modifying original post - just attached that video so anyone willing to help or learn about issue does not need to go to external site.