HX FX Stuck in Boot Loop

[areabassist]

HX FX came up with blank LCDs (backlit, but blank). Still connects to HX Edit and shows patch info. I reseated ribbon cables (the main one had been disconnected) but that did not fix it. I forced Update Mode and successfully updated to the latest version using Line6 Updater. It's still stuck in a loop when I try to boot it up - about every 10 seconds I can hear the relays clicking. These are down to $500 new so I'm not sure it's worth taking to a shop at $120/hr labor plus a board or whatever. 

 

Any suggestions?

[areabassist]

Also - I'm using the original power supply, and also tried a 1 spot (1700 ma) with no luck

[Schmalle]

Now that you've excluded the power supply from the list of possible causes two things come to mind that you can give a try:

1) You mentioned you reseated the "main" ribbon cable. The HX Effects actually contains two primary ribbon cables:  
 

The wide main ribbon cable connecting the main processor board to the display/footswitch board.

A smaller, secondary ribbon cable that specifically routes power and control data to the upper scribble strip/LCD assembly.

If the main processor tries to boot, queries the secondary display board, and receives a short circuit or no response due to a bad connection, the bootloader will crash and force a reset loop.

Open it back up. Disconnect both ribbon cables. Clean the gold contact fingers on the ends of the cables using 99% Isopropyl Alcohol and a Q-tip. Ensure they are seated absolutely straight and deeply into their Molex plastic collars before locking them down.

 

2) Because you just did an update while the unit was in a semi-broken state, it is possible there is a corrupted global settings file or "problem preset" causing a boot crash.

Even with blank screens, you can force a hardware reset using the physical switches:

Turn the unit OFF.

Press and hold Footswitch 6 (top right switch) and the TAP switch simultaneously.

Turn the unit ON while holding those down. Keep holding them for about 10-15 seconds.

If it successfully clears the state, the boot loop might stop, allowing the displays to spring back to life.

 

Good luck finding the cause of the issue, share if you find it.

[areabassist]

I have progress but not complete success yet, and some important info that I originally thought might not be important.

 

This started with a shot of Fireball getting kicked onto the unit. Wiped it off at the gig, didn't seem like a lot of liquid but it probably got in around the displays and maybe footswitches. (This was near the end of the night and the unit kept working through the last couple of songs).

 

At home the following day when it didn't work right, I opened it and discovered the disconnected ribbon cable (possibly caused by my singer shaking the unit after wiping it) and assumed that was my actual/ only issue.

 

After posting this I did notice sticky areas and in addition to your 2nd ribbon cable suggestion I cleaned the boards and the displays with isopropyl (once or twice over with a soaked toothbrush) and let it dry for a day. Today the displays are working again and I thought I was all good but it's still stuck in a boot loop.

 

I tried a reset (tap +6) and another force update using line 6 updater. It updated to 3.8 but still keeps rebooting. 

 

I think I'll try to clean it more thoroughly (also will use 99%, this was 91%).

 

AI suggests I may be screwed at this point (component fried) but it's worth a try.