Electronics > Repair
Siglent SDS1202x-E fried FAN driver transistor - SOLVED -
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tppc:
Hi everyone,

My SDS1202x-E is up and running again!  8)

While disconnecting the 12 pins power supply connector, I broke the SMD capacitor C176.
There was no visible damage, but in fact, it was actually shorted.
This did pull the stand-by power from 5V down to 1.25V (reference voltage of the 1117 LDO voltage regulator U17).
Thus preventing the mainboard to start.

 I replaced C176 since there was no marking, I chose a 10 µF MLCC SMD 1206 I happend to have in stock.
The scope starts nicely and the fan spins at its normal speed.

Damned, I though I had a valid reason to upgrade to the new SDS824X HD oscilloscope  :palm:
Not this time Marco, not this time!  :-//

Thanks to all contributors who helped me in any way.
CharlotteSwiss:
Okay. But have you replaced Q34? With what?
tppc:
Yes, I did replace Q34 with a 2N7002 (SOT23 SMD) MOSFET I had in stock.
I know, 2N7002 caracteristics are not even close to those of SPN3402.
However, it does the job (temporarily).
I ordered a kit of 40 SPN340x MOSFETS.
 
CharlotteSwiss:
Ok, so long live the 1202X-E
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