820-00840 bootloop

[crazeej]

Hello guys!

A1708 had liquid damage around u2890 and resistors.

Replaced the resistors with new one and the machine is firing up. Anyway it's stuck in bootloop.
Apple-Logo - after 2-5seconds it's restarting so on and so forth.

No loading bar. Only apple logo

Smc bypass it's loading half way up and restart again.

Using extern SSD over usbc adapter. Don't have a onboard ssd.

Is this maybe a efi issue or could be u2800 damaged? I pulled the shield up, there was no liquid visible.

Thx a lot

[crazeej]

Re: 820-00840 bootloop

Nobody? -.- any hint?

Could someone clear me ? On older MacBooks is it a bit easier than this one.

Yellpppppp

[sicilianul]

Re: 820-00840 bootloop

Try to reinstall OS with external SSD. Or try with a original SSD in the slot.

I've had some issues when used external SSD.

[crazeej]

Re: 820-00840 bootloop

Try to reinstall OS with external SSD. Or try with a original SSD in the slot.

I've had some issues when used external SSD.

I tried it with a few external and internal ssd. S with no change. Changed the efi with a known good one. Same issue, now I reflowed u2800 and checked the resistors. Could that liquid on r2891/92/92 killed a part from the cd3215?

Thx for assistance!

[crazeej]

Re: 820-00840 bootloop

In verbose mode I'm getting until this point. What should load next? Than restarts again .. Anyone a idea?

[crazeej]

Re: 820-00840 bootloop

Aht telling me : vdh002 - memory problems

Mri getting stuck at ram test

Hackintosh forums have similar problems, could be related on ram efi?

Hmm dead cpu or ? -.-

[MobileXT]

Re: 820-00840 bootloop

if you have a 12.54v on PPBUS_G3H then your CD3215 should be ok

[MobileXT]

Re: 820-00840 bootloop

also check your PP3v42_G3H if you have a constant 3.42v if fluctuate that could be the reason for a boot loop. Also check you SMC_RESET_L you should have a 3.42v.

[crazeej]

Re: 820-00840 bootloop

also check your PP3v42_G3H if you have a constant 3.42v if fluctuate that could be the reason for a boot loop. Also check you SMC_RESET_L you should have a 3.42v.

OK, thx Mate. Im gona Check it later. I'm at work right now.