I thought I'd throw out some of my personal experiences in the last 12 months with Intel iMacs, 2.5" SATA SSD drives and Fusion drive data recoveries.
As a backgrounder, Apple never fitted a 2.5" SSD's to these iMacs. Apple's SSD option was a system of 32GB NVMe blade drive (NGFF connector) and Seagate 1TB 2.5" HDD, married together in software to become a Fusion drive. Non Fusion systems have just the 1TB Seagate HDD.
So, the most common reason an iMac comes across my bench is because it's either ridiculously slow, or it fails to boot at all. The most...
reformatt
Badcaps Legend
Last Activity: Today, 06:12 AM
Joined: 02-17-2020
Location: Noosaville
-
Intel iMacs, 3rd party SSD failures and Fusion setups
Last edited by reformatt; 12-18-2024, 10:37 PM. -
I did have an iMac once where I had 3 beeps. Initially thought it was RAM, but turned out to be a shorted PP3V3_S0 power rail from the headphone jack board. So check all your switched S0 power rails for shorts before blaming RAM itself.
These boards won't boot without all RAM IC's fitted and working. If known good RAM's and switched power rails check out, then this would be a PCH issue I would think. -
4 ohms on C9091 isn't good, that's your SSD 2.5V power rail. Usually if it's one of the decoupling caps (C9089 etc), it will read dead short. Non zero is often a NAND that's failed due to the overvoltage from the failed TPS61280 (can be one or more, or all of them). Remove U9080 and see if your PPBUS_G3H short is removed. Alternatively, use 1V voltage injection and thermal camera if you have one to pinpoint the issue.
BTW, the NAND's are combined in a RAID 0 stripe by the T2, so data definitely gone when this happens.Leave a comment:
-
Dead A1990/A2141 I immediately check for simultaneous shorts on PPBUS_G3H and either of the PP2V5 NAND power rails. TPS61280 failure is pretty common (U9080/U9580). This TI IC has killed many a Macbook over the years by pumping 12V straight into their SSD's. In true Apple fashion, they repeat the same Engineering mistakes over and over again, and they are still using this IC on the latest M4 Mac Mini removable SSD's. Built in obsolescence at it's finest.
With any luck, you just have a PPBUS short, and it's a decoupling cap on one of the chicken wings. Most common on A1990 is C9081....Leave a comment:
-
Working on a dump of a 2017 iMAC (820-00579 board) with a locked BIOS. It's the current version from Ventura (529.140.2.0) and showing that APFS driver not present. Just a cosmetic thing so not a biggie.
Also noted there is no Save As option. If you make a change (e.g. clear NVRAM) and don't save it, there is no option to Save, other than to go back in again and do the same action then hit save.
[ATTACH=JSON]{"data-align":"none","data-size":"full","title":"image.png","data-attachmentid":3526825}[/A...Leave a comment:
-
I just refurbished two 2015 A1398 with missing batteries. One was EMC 2909 (IG), the other EMC 2910 (DG). The IG machine will boot into MAC OS without battery, but will be throttled and slow. The DG machine will crash during boot as the peak current demand cannot be met with the charger alone. Actually as an aside, the DG machine did have a faulty trackpad and did boot to the desktop ok (minus trackpad and keyboard of course). These machines will pull up to 4 amps or more during boot, so your power supply must be able to at least deliver that.
Chime isn't always a reliable indication...Leave a comment:
-
Leave a comment:
-
Data recovery from Apple SATA SSD MZ-DPC512A/0A2
Customer brings in this severely liquid damaged 2012 Macbook Pro A1398. Primary thing he wants data off this SATA SSD he has fitted and it's not being detected on a spare motherboard. Other drives are ok.
Noted a small amount of corrosion on the SSD on one component, even though it was coated in that black glue. The component in question does read short to ground. Wondering if any one else has a working 512GB SATA SSD from a 2012 MBP (either A1425 or A1398) to verify I've got a bad cap. Or maybe some diode readings would help.... -
PQ101 or PQ102 will likely be shorted. Quite common after a main power rail short. BQ IC will disable charging in that event.Leave a comment:
-
Most common issues I see on old iMac boards are shorted caps. These are usually at the bottom end of the board, either in line or below the bottom of the screen (as the air is drawn up from the bottom by the fan, and dust/moisture accumulates mainly in this area). The headphone jack at the very bottom is also a common fault as PP3V3_S0 routes here and there's a decoupling cap on it that goes short.
Initially I eyeball each cap under the microscope in the bottom of the board (e.g. C3387, C3287, C7661 etc) and check if any sub-rails are shorted. You can run the board on the bench from...Leave a comment:
-
iCloud activation lock is linked to multiple hardware items on T2 and above, and not just linked to serial number. It was changed years ago by Apple due to some practices that China were using to bypass the locks on iPads.Leave a comment:
-
R8024 and R5400 are for current sense; it should just read as a short and aren't physical components. R8029, C8029 are NO STUFF in the schematic, so not fitted during production.
PP1V8_SUS is generated from U7800 (3 of 10), no where else. Check that resistance to ground at L8020 isn't short or low. Then check all your signals going in: PP3V3_S5, PP5V_PMICLDO, PM_SLP_SUS_L. Its a buck converter, so you also check the feedback components R8025, R8020, R8021, C8020. The PMIC shouldn't be underfilled, but if it got liquid damage under it, it may need to be removed and reballed....Leave a comment:
-
PP1V8_S0 is derived via a load switch from PP1V8_SUS, which in turn is generated by PMIC U7800. Enable is PM_SLP_SUS_L (measure at R1458), output is via L8020. Check for low ohms etc on the 1.8V lines, especially around touchbar connectors.Leave a comment:
-
[ATTACH=JSON]{"data-align":"none","data-size":"custom","height":"177","title":"image.png","width":"307","data-attachmentid":3509439}[/ATTACH]
Usually this data line is shorted after liquid damage to J8500. Should still boot, but you won't get an image. Very common fault....Leave a comment:
-
Leave a comment:
-
[ATTACH=JSON]{"data-align":"none","data-size":"custom","height":"130","title":"image.png","width":"233","data-attachmentid":3503854}[/ATTACH]
The gas gauge line is BATT_SWI and is used to communicate with the controller in the battery. Absence of data on this line causes a panic condition and a reboot is asserted because of it. Can be either from a bad connection, broken pin or faulty battery.
My recollection from when I was doing these that it would at least boot to...Leave a comment:
-
These batteries aren't intended to slide out. The battery is glued down, and the motherboard is then placed on top of the connector, and held down with adhesive. You either take it out or lift it up slightly with a pry tool to allow the battery to pop over the screw hole. Apple products are not designed to be repaired easily, and in fact come with a lot of booby traps for the uninitiated.
The reason it is boot looping as the iPad can't talk to the battery's gas gauge lines. Battery is either faulty or the pins on the motherboard side were damaged when you pulled the battery. On other...Leave a comment:
-
From experience with liquid damage on Apple boards, you need to examine every passive component with dull grey end caps, as the pad underneath is often corroded (or the connection is bad). Often get boards come back with intermittent issues unless you do that. If the damage is extensive like you say, I write them off as the repair will bounce back to you. I just remove and replace from a donor en masse but I don't waste too much time on them.
First thing for me would be to replace the LCD connector and backlight IC (U7701). The feedback pin is often corroded (pin 5).Leave a comment:
-
If the high side FET shorted, then you got 15V directly into the CPU. Pretty much game over at that point.Leave a comment:
-
Check the I2C SCL/SDA lines to the battery. Fan will run at 100% if missing. Have seen this with a liquid damaged battery flex cable but could also be the connector itself.
Fan will also run flat out if tach is missing. Use MAC Fans control or similar to see if there is a tach present.Leave a comment:
No activity results to display
Leave a comment: