Recent content by KMCC

Sorry for slow response. USB activity yes. Connected an external via display port adapter and it works. I tried a flashlight to see if video shows without backlight but can't see any video. The 5k panel was installed on my other iMac and works. The 5k panel on m other iMac also doens't work...

System running great. Upgraded SSD and it boots but no video/screen. Tested 5K Panel on another iMac and it works. Tested with a known good 5K screen results same. I also tested video cables screen to board and no help. Is there a way to test the connector on the logic board to determine...

Thank you again. I hope this is what you are asking for. Using a USB to SATA adapter that has a blue activity light. I tested both USB c and USB 3.0 ports and here's the findings. USB 3.0 port Power on.. LED 1 on already LED 2 on and as LED 3 turns on the Blue activity LED on the adapter comes...

Thanks for the response!!! I don't have a clue why I kept using LVDS?? Brain poof!! I have a generic USB tester and ran the following tests. Plugged into USB C TB3 port and voltage showed 5v and it came up on the tester screen just after pressing power and stayed on past the chime and didn't go...

Just wanted to update from previous post regarding this 2017 iMac 27" 820-00609 I have not replaced the BIOS chip yet and wanted to get a better understanding of how a BIOS chip could cause this issue. New info: Cable replaced for rule out. If BIOS then what are symptoms of a problem BIOS...

As I was getting prepared to replace the BIOS chip I noticed a SMD near the BIOS chip that looks different. I do not have schematics or boardview. If anyone has info on the component I drew a line to could you describe it or marking ID but also the see the component is bad or not. Thank you.

Trying to show actual board and describe previous post. I don't know if I'm going in a direction right or wrong. circle seems more like it.

820-00291 is the boardview/schematic using Pic shows the area I'm describing Below the Coin pads is a 470uF cap which reads find. The 470uF caps to the right 12 of them in a row, all read positive side to ground as short (continuity test). Is this normal? I only looked by the BIOS ic because...

820-00609-A I know from older macs like 2011 ish, that the GPU's failed often and some would try to reflow/heat to get them to work temporarily. Or use the Tiresias which I have to bypass the GPU onboard so is this "possible" GPU issue caused by overheating or high temp? There's not much on...

Wow.. thank you for the info!! Results. Did the SMC reset and the fan did spin up to high so it was successful correct? I connected only a apple wired keyboard and TB3 to HDMI TB3 to TB2 and tried booting into Safe Mode (did not) Diag Mode (did not), tried both video outs by going through the...

I plugged in a USB tester (all 4 USB show 5v). I may sound dumb here but in case, USB C/TB3 (both ports don't show any voltage). I do see a backlight come up on the external via TB3 to HDMI (flat scree) and TB3 to TB2 Cinema Display. After chime both ext. screen setups brighten up like a...

After installing the screen and powering up the following: LED 1 2 3 and 4 all came on. After 7-8 seconds from power button pressed the 4th LED GPU goes dim to full lit. After 55-60 seconds it reboots. This is repetitive. Any ideas? Please..

LED 1 2 and 3 on, chime good, LED 4 seems dim, black screen. Using ext. Cinema via TB2 and boot the cinema seems to get bright but nothing. Tried SMC, PRAM resets, and removed coin battery, still no change. no evidence of liquid damage or physical damage on the board. PS visual looks good to...