| Electronics > Repair |
| What more i can do? |
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| Swake:
In a working machine no one is swapping out these DRAM SIMMs, so this bend pin is unlikely to be the root cause of the initial failures. But as these machines and boards are used in difficult environmental conditions maybe contact corrosion is at play here. Except for cleaning everything with a contact cleaner this is very difficult to diagnose. Are the boards also subject to mechanical stress, like shaking? In this case I would also visually check all solder joints. I assumed from previous posts that all failing boards are failing in the same way, that seems to point to a single type of failure, but maybe this is sand in the eyes and there are several different causes and potentially also boards with more than one issue. |
| Swake:
--- Quote ---I'm just haunted by... I am also still haunted by.... --- End quote --- Let me tell you that I'm also a bit haunted... by the OSC3 signal. It shows as 2 V, that seems very low for a 5 V system. Too low. But I'm no expert in this, I don't really know if 2 V would be enough or not to make it work. Is this OSC3 used for the Tornado chip? Is this Tornado chip running on 3 V or 3.3 V ? Then maybe the 2 V signal is barely good enough. We don't have the datasheet for the Tornado chip, this document can tell us if the 2 V is enough or not. I think it was measured with the scope, the scope has a 1 MOhm impedance input. Is this too much of a load for the crystal? Sooo many things we can still explore on this board. I wouldn't say it is a Christmas present but it comes close for people that like a little challenge :-DD |
| asis:
@Swake You yourself provided a photo Reply #510 on: Today , and the location of FRAM (FRAM = "SIM 2"). And the fact that the design uses a SIMM72 connector does not mean anything. The connector layout and functionality may differ from the standard applicable to SIMM72 DRAM ="SIM 1" For example: why does FRAM need RAS/CAS functions (pin's: 33,34, & 40~45)? |
| asis:
I have a plot of events developing over many years: During the operation period, equipment failures occurred. But in order not to cause downtime, entire controllers were replaced in time pressure. What was removed was put on the back burner, then fell into someone's hands and was randomly mixed up (PCB & FRAM, DRAM), so to speak, at the "repair" stage. In the end, all this stuff got to the respected 222Lab_Test222. And we are all writing this wonderful, exciting novel. We need to take a breath and start again. - Continue... |
| Swake:
Forget about OSC3 for the moment. Reason: It is a 2.4576 MHz Crystal and that frequency is a very standard one used for UART purposes. Probably nothing to do with the Wacom Tornado ship or anything that starts the board. |
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