820-4924-A Runs suspiciously slow - what could you measure?

[pb1911nt]

Hi

I have now a 820-4924 (with a i7 and 16GB).
I would like to get the device working again for me.

The Problem is the Device comes to me with a "dead" ssd. I tested on a other 820-4924 (i5-8gb) board and the MAC OS Installation stopped working with this SSD.
Well i hope/guess its was a easy peasy Fix - New SSD And its working again.. But No!

I don't know exactly how the procedure should start. But the LCD panel goes dark - then the "chime"(?!) sound comes and only 2 or 3 seconds later the apple comes.

it doesn't recognize the trackpads either!

A memory test with Memtest ran for about 4.3 hours without any problems - i.e. without errors.

Now I don't know exactly what I could measure and where.

I have the schematics (and I suspect an outdated board view file?! Some chips are listed as 4 pin even though they are only 2 pin?!

I have a power supply with 85 watts (from Apple and it also works - other devices of the same model do not do faxes.

My idea would be to first take the other board that works with the i5 - 8GB and use this as a reference to measure? But... I think my thought would be stupid again because the boards have different equipment and therefore the measurements shouldn't actually be usable??

The device itself works "stubbornly" and often gets stuck in Mac installations - especially with OpenCore!!! I finally got macos monterey 12.7.6 installed for testing. But that was it.

It's somehow slow and sluggish to operate.

How would a “defective CPU” manifest itself? Somehow I suspect this.


Greetings from Germany !!!

[reformatt]

MAC's will throttle the CPU to the slowest speed if there is no trackpad connected (or it's not working). Usually you need to remove the battery to remove the trackpad on these old A1502 machines. MAC OS installation is painful when it's throttled and likely explains why it fails.

Try connecting another trackpad temporarily and see if it's just a faulty trackpad. They do get liquid damaged, or sometimes just fail.

[pb1911nt]

oh ok wow?! I'll test it after work. The battery has already been removed because it doesn't work. Would it work normally if no trackpad is connected?

[reformatt]

oh ok wow?! I'll test it after work. The battery has already been removed because it doesn't work. Would it work normally if no trackpad is connected?

The battery is glued in with some pretty strong adhesive. I use a stiff credit card with IPA, but newbs often pry the battery out, damaging the trackpad in the process. Or they damage the cable. One or the other.

MAC's will always throttle if there is any missing sensor data, and the trackpad contains one. So if it's missing or not working, this will result in a throttled CPU.