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A2337 - dead after being connected to failing projector

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adrko

Member
A2337 - looping from 5V to 20V

Was connected over Belkin or some other adapters via HDMI, to a projector that has failed.

It started with power cycling on both ports, when it gets to 19-20V power meter shuts down and goes from 5 to 20V again

I was hoping for an easy win and just replaced both CD3217 from 100% known good donor, both chips known good

Nothing has changed. I looked at it under thermal cam after taking the shield from thunderbolt/USB C controller chips

one of the chips was warming up a little before cycle ends, decided to replace both. No changes.

I could not find any shorts on main power lines, not sure what else can I do - or should I give up on this.

Please advise and thank you for reading the post
 
2informaticos

2informaticos

Administrator
Staff member
Did you maintain the position of the chips?
Still one of UF000/100 warms up?

Check if works with charged battery.
 
A

adrko

Member
Hello

Thank you for the reply.

I most likely did not maintain the position of the chips, neither CD3217 nor UF100/UF000

Switched 3217 around and still same behavior with bare board on the bench.

When board in the topcase with battery plugged:
1. Connectred to port parallel to UF00:
- stays at 5V with slight spikes in amps when
- barely noticable heat on UF00/UF100
2. Connectred to port parallel to UF100
- cycles from 5V to 19/20V and shuts power meter off
- UF100 warms up slightly then after a second warms up significantly in the middle. Then cycle repeats

I assume I should have maintained original position of UF00 and UF100, but I don't have a stencil for those unfortunately. First time I reballed both with solder balls without a stencil
 
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adrko

Member
Understood. But after I switched UF400 and UF500 around the behavior is exactly the same. I'm trying to switch around UF00/UF100 now
 
A

adrko

Member
I am very confident in my job with CD3217, but I found one potentially oxidized pad under UF100, on VCC3P3_ANA
 
A

adrko

Member
I have decided to do motherboard replacement instead.

I also put both CD3217 back to working donor, they work fine - the position does not affect them. I also tested it by swapping places again. They work fine and mac is charging fine.

Thank you for your help, I might try to get back to this motherboard, there were more problems with unstable main voltages.
 
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