cancel
Showing results for 
Search instead for 
Did you mean: 

Q-Code 77: Strange interaction with Corsair 250D Case

1blackwatch
Level 7
Hello,
I'm using a Maximus Impact VII.
Not very long ago I started getting Q-Code 77 (PCH DXE Initialization (PCH module specific)). After some experimentation I have found what I am 95% sure is the cause of this problem, and would like some help pinpointing how to fix it.
If the top panel of my Corsair 250D is fully screwed in via its thumbscrews, this error occurs and the computer will not boot at all. However when I remove the thumbscrews and open the top panel just a bit, it boots normally!
I should probably do more experimentation- like see what particular components would be affected by the thumbscrews being fully engaged, but does anyone out there have ideas?
Thank you!
447 Views
5 REPLIES 5

Rakuun
Level 7
Are the thumbscrews making contact with anything when fully tightened? More than likely they are touching something and causing a short. I'd bet money on it.

1blackwatch
Level 7
Still can't really figure it out. Thankfully this is only a nuisance and not a serious issue (AFAIK).

Anyway, I have narrowed it down to 1 thumbscrew - the other can be fully engaged with no problem. The problematic screw, however, will cause Error 77 and not boot the system when fully engaged (but works normally and will not Error 77 when ~50% screwed in).

The screws do not touch anything at all besides the case. Thus I think it is the top panel fully coming into contact with the rest of the case causing the problem. When the 1 problematic screw is fully engaged (the other being irrelevant) the top panel is pushed into being flush with the rest of the system. I.E. a sort of "closed-loop" cage is created. When it is not fully screwed in, there is a ~1cm gap between the front panel and top panel.

Totally random guess but perhaps a piece of the underside of the ROG Maximus Impact VII is touching the case. When the top panel is completely screwed in, some kind of short is happening. But as long as the top panel is not 100% attached, it boots fine.

So strange! I don't think I'll get a 100% answer on this one. Figured someone somewhere will be Googling this someday. At least I know what's causing the problem in the first place.

Rakuun
Level 7
Have you tried insulating that area with some electrical tape? If you have access to a multimeter, use it to test where the short is coming from.

Great idea with the electrical tape! I'll try that.
Also I've been meaning to get a multimeter - don't have one yet but know they can be cheap.

Edit: I covered a few areas with tape and the only thing that happened was the Q-code changed from 77 to 76 🙂
I removed all the tape and the code went back to 77. Tried a 2nd time to do a better job with the electrical tape coverage and got code 76 again. I consider it progress 😉
I may try again tomorrow. But I'll definitely put a multimeter to the area when I get one.

1blackwatch wrote:
Great idea with the electrical tape! I'll try that.
Also I've been meaning to get a multimeter - don't have one yet but know they can be cheap.

Edit: I covered a few areas with tape and the only thing that happened was the Q-code changed from 77 to 76 🙂
I removed all the tape and the code went back to 77. Tried a 2nd time to do a better job with the electrical tape coverage and got code 76 again. I consider it progress 😉
I may try again tomorrow. But I'll definitely put a multimeter to the area when I get one.


Check your motherboard standoffs.... I know its a pita, but you could try and remove the MB from the case and place it on a non conductive surface and see it the problem persists.