This video is sponsored by JLCPCB.
https://jlcpcb.com/?from=ripfelix
This video is the first part of the repair of this console. This COK-001 motherboard had an A0403034 SYSCON errorcode indicating a bad GPU. Either the solder balls cracked or it's bumps failed.
I wanted to evaluate the utility of the pressure and heat tests on a PS3. These tests have been used to distinguish between BGA and Bump failures. Techs like Octal450 (Josh Davidson) have used it with great success on the XBOX 360, which suffers from a known BumpGate affected chipset. In his experience, if a console responds to the pressure test it confirms a BGA defect more often than not. In that case a Reball is a viable repair. On the other hand, if the pressure test does nothing, it does not rule out a BGA defect, but makes bumps more likely and therefor the proper repair would be to replace the GPU entirely.
The heat test on the other hand, is designed to raise the temperature of the underfill, a glue like substance under the die, above it's thermal glassification temperature. This essentially melts the underfill, making it malleable. Do not confuse this with melting solder. Solder cannot melt at these temps! The heat test allows the die to re-seat, unlocking pent up strain, and the bump cracks may be pressed back together. They do not melt back together! They're just touching, like pressing two wires together. It can make a temporary connection to simply confirm the bump failure.
If the heat test is successful after an unsuccessful pressure test, that is good evidence of a Bump failure instead of a BGA failure. This is not a definitive test methodology. It is qualitative. It gives you a more likely than not sort of confirmation.
However, just because the heat test can cause the crack to press back together, that doesn't mean it always will. It could re-seat in such a way that the crack is still open. Therefore, if it doesn't work, that doesn't rule out a bump defect. Because of this, these are meaningful only in case of a positive test result. A negative result does not rule anything out.
Example 1: Syscon error A0403034. You press on the chip and it boots up. When you release pressure it artifacts. Afterward you heat up the console and it does nothing different, still not working. (Pressure test +, heat test negative). Diagnosis, BGA defect. Repair = Reball or replace GPU.
Example 2: Syscon error A0403034. You press on the chip and it does nothing, no matter where you press. Afterward you heat up die and the console boots. (Pressure test -, heat test +). Diagnosis = Bump defect. Repair = replace GPU.
Example 3: Syscon error A0403034. You press on the chip and it boots up. When you release pressure it artifacts. Afterward you heat up die and the console boots. (Pressure test +, heat test +). Diagnosis = BGA Defect and potentially a Bump defect as well, but it could just be the heat warped the board and made the BGA connect. Repair = replace GPU to be safe. You could take a chance on a reball, but if there was a bump failure too, you won't know until it returns in a few months. If you're selling the console, that would really suck for the customer!
Example 4: Syscon error A0403034. You press on the chip and it does nothing, no matter where you press. Afterward you heat up die and still nothing. (Pressure test -, heat test -). Diagnosis = Not enough evidence. Repair = replace GPU to be safe.
0:00 Intro
2:20 Sponsor
3:39 BGA vs Bump Defects
8:29 Pressure Test
10:36 Heat Test
18:13 What a BGA Defect looks like
20:31 Results & Discussion
