RP602Z330C questions

[WickingHour]

I recently found that removing the ENX (RP602z330c) cleared a Vsys fault. It was discolored too. I ordered a new one RP602Z330C e2-f. After installing the new chip the Vsys short was back. Are there certain versions of the chip that are not compatible? Not sure about the e2-f.

Is this chip difficult to align where Vsys short is common if not on exactly right? I thought maybe I used too much heat, but The chip pins do not seem to be shorted (at least not after pulling the IC again).

When I installed the new chip I referenced a picture of the original one on the PCB, so it should have been aligned?

Just wondering if you seasoned repair techs have encountered issues when replacing this IC.

Thank You.

[jkyoho]

had-cpu-xx v2 board?

[WickingHour]

HAD CPU-10. Not sure how to tell if V2.

[WickingHour]

Backplate says HAC001. I’m thinking V1. Does V2 have HAC001(01)?

[jkyoho]

back plate does not tell story, HAD-CPU-10/01 tells it is v2 model.

Are you able to tell if there is a small components next to 2R2 coil ? like this below in orange circled.

Cap near bq short of low impedance?

[IMG_7558] I’ve replaced bq and the cap circled in red is the only one in the area that doesn’t give me any readings in resistance and also beeps on both sides in the diode setting on my multimeter. Does anyone know if it’s low impedance or if it’s shorted. Any other places I can look on the board if it is shorted?

[WickingHour]

Yes it has the diode under the cap like this image

[WickingHour]

I reballed the RP602z330c and put it on again. No short this time. I studied a picture and lined it up as precisely to match the picture. Do you know if there is a board alignment guide to position this chip? I thought I could see a circle mark on one corner, but there was some flux and difficult to see.

Thank you for taking time and helping people on here.

[jkyoho]

IC orientation should look like this. FYI since you have the diode there, typical Vsys having around 120 ohm to ground resistance is normal for the v2 board you have

0.7v on 3.3v rail without ENxx chip

Just picking this up again, [voltages1] I saw this on another thread and I probably need to replace the ENxx again possibly, but the resistor where it shows 1.8v here is the one that was knocked off and I replaced with a 100k having seen an image on another thread marked with this. Is 100k correct for this resistor? Cheers Stot

[WickingHour]

Thank You for the info. I had a dead 0 ohm short. Injected 4.2V 1 amp current limit and it went up to the limit. Weird thing was the thermal camera did not show anything other than the inductor I injected the voltage into getting warm. The RP602z330C did not indicate a thermal issue, but when I removed it again the short cleared.

I watched a video from the lady that does the iphone repairs where she says sometimes shorts under IC chips do not generate a visible heat signature because the chips are good at dissipating it.

I think my Max 77620 is bad also, unless I did the same thing and didn’t get it aligned good. When I put it back on without the RP602z330c I had the Vsys short also.

I’ve noticed caps around the max ICs and CPU will beep but I think they are ok reading low resistance on 1 side.

Thanks again. I really hope to get this board working.

[WickingHour]

I noticed that green circle on my board like on this picture (Top left corner of chip). I think you are supposed to put that corner in the center of that mark, but it’s just a theory. Looks like where this chip is placed anyway.