| Electronics > Repair |
| Tektronix DPO4054 stucked at tektronix splash screen |
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| JohnPi:
Does anyone have a photo of where U308 is on the PCB ? |
| analogRF:
upper left corner, above the ADC clearly marked U380 what are the symptoms? that chip is not the only fault that prevents the scope to boot. actually when that chip is checked by the firmware, quite a bit must have fallen into its place already, PA Bus doesnt get accessed/checked until the scope software starts. Firmware must have been successful before that do you have splash acreen or no acreen at all? |
| JohnPi:
Actually it's a DPO 4104. The splash screen (and the fan) comes up within a second or so when powered up, but remains stuck there. I measured the power supply voltage; it was OK. |
| analogRF:
check all the voltages on the board, there are many DCDC converters, you need to check them all first but most probably they are ok :( yeah, unfortunately U380 is not the only thing that can cause this...serial debug console can tell you if it is the PA Bus that is causing this or not. If that's the case, then U380 is the culprit. YOu can also check it yourself if you have a high frequency FET probe and high freq scope or spectrum analyzer, that chip is a simple divide 4 IIRC have you tried to "force" the firmware via the USB stick (see the firmware installation manual)? use a USB stick that has LED showing data activity. If the USB at least gets accessed, I think you have passed a critical point and the scope software starts a little after that, so there is a chance that U380 is stopping it but if USB does not get accessed, the thing is stopping in earlier steps and has nothing to do with U380... |
| JohnPi:
I'll try the USB stick 1st. My SA goes to 1 GHz (my other scope is only ~ 200 MHz), I'l check if I can see anything with the SA. Where are the debug console pins ? |
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