| Electronics > Repair |
| Tektronix DPO4054 stucked at tektronix splash screen |
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| ApertureScience:
Also interesting function that tells a bit about the memory layout. Not sure why it seems to show gaps though... --- Code: ---ushort convByteIdxToGrpIdx(uint offset) { int local_20 [7]; local_20[0] = 0x10003; local_20[1] = 2; local_20[2] = 0x50007; local_20[3] = 0x40006; return *(ushort *)((int)local_20 + (offset & 7) * 2); } --- End code --- This looks weird, maybe some magic on the address bus. 0x10000 is very close to 2^16, implying some 16bit wide bus. Or.. I am totally wrong about my assumptions and everything is specified down to the SDRAM architecture to achieve the necessary acess times. |
| MarkF3837:
On my DPO4104, there is an opening in the bottom of the metal shield. Inside is a 2-row, 20-pin 1.27 mm pitch connector. With the 'scope upside down & facing away from you, the second pin from the left in the top row is the TxD pin (data from 'scope). The pin to its right is ground. I haven't searched for the RxD pin. Signal level is 3.3V. Data rate is 9600 bps. |
| Skyhi:
Hi all, just wanted to say I joined this forum because I was looking for pointers on repairing a DPO 4104. In my case re-flowing the BGA flash IC's U840, U832, U821 and U820 solved my 'stuck at boot' problem. I flooded them with flux and used a heater underneath and used a hand air station with a small noozle until I saw them bubble and 're-seat' themselves. If it happens again I plan on removing them and re-balling (with leaded solder of course). Been working great for a while now! :-+ Best regards, Will |
| analogRF:
--- Quote from: Skyhi on July 30, 2022, 03:42:06 pm ---Hi all, just wanted to say I joined this forum because I was looking for pointers on repairing a DPO 4104. In my case re-flowing the BGA flash IC's U840, U832, U821 and U820 solved my 'stuck at boot' problem. I flooded them with flux and used a heater underneath and used a hand air station with a small noozle until I saw them bubble and 're-seat' themselves. If it happens again I plan on removing them and re-balling (with leaded solder of course). Been working great for a while now! :-+ Best regards, Will --- End quote --- may I ask what temperature/air speed did you use? Did you also put the board on pre-heater? This is a huge and thick board, I am very reluctant (read scared :-//) to do reflowing |
| Skyhi:
I did use a pre-heater underneath the board - it is a fairly small hot air setup and it had it set all the way on for heat. As for the hand air station the nozzle I used was around 7mm in diameter - I had the heat to max and kept the air flow fairly low to keep things from blowing around. I also removed the backup battery before I started heating things just to make it a little safer. When I get back to work on Tuesday I will list the equipment that I used and give you a better idea of the airspeed I used. I had initially figured out something was up in that area of the board just by using my heat gun at home just on the top of the board while trying to power up the unit and it booted! But as soon as it cooled off again it would freeze as described. I don't normally like putting as much heat into the parts as I did but I figured the die in the packages where insulated by the plastic and I really did need to get them hot enough for the solder underneath to liquefy and re-harden to achieve a good connection after the process. |
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