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Seventh generation of iPad, released September 25, 2019, available in 32 or 128 GB models. Model Number A2197.

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PPVCC_MAIN Interesting Diode Value

Hello one of my customers brought me an ipad 7 and it is not turning on. When I checked it under the thermal camera saw that big power is getting hot on power supply connected to the battery legs and then sarted measuring PPVCC_Main diode value first and found out that it is around 0.170 and I know that it must be around 0.360 .

Because of this first changed the big power as I thought it is getting hot when I plugged it to the power supply without trigger. Nothing changed then I tried changing U2 and nothing changed with it also. And still same diode value on PPVCC_MAIN line.

What can cause this problem and how can I sort this out?

Will be much appreciated if you can show me a way to sort this out.

Thank you


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hello there,

repairing expensive electronic devices in a "I'll replace this, then that and see what happens" scenario is the wrong way. To fix something, you need to know how it works. If you don't know, just learn. Knowledge and books do not bite. You replaced Tristar unnecessarily. In this model does something else.

the resistance value of the VDD line (this is not VCC - the marking makes a difference) does not necessarily mean a short circuit in this place. The main power manager rarely crashes like this. Remember it's a semiconductor. Make drawings, photos and check the scheme of this subsystem. At the input there is a switching transistor to the backlight line. If its path has not been closed, it will give a short-circuit image on the PMU. Follow the rabbit.

take a look at my blog, you will find some advice on similar issues (address in "about me" tab), although I will admit that iPads have not yet been prepared. Maybe in the near future I'll be able to find the time to do that.

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First of all let me explain how I started this business. Im not an electronic technician. I was working in tourism for many years, then after pandemic period I found out Im interested in this business and read + watched everything I could found on internet.

Thank you for showing me a way to look. I really didnt know anything about electronics before and still trying to learn more and more.

Is there anyway to show me a certain place to check instead of giving me a general advice.

Thank you



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Aydoğan Emre GÖKTEPE zal eeuwig dankbaar zijn.

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