Core Tip: received today a fellow T61 IBM notebook standby machine; repair, the first observation of what are moving, visually dynamic power connector of the first P-channel MOS transistor, the upper and lower tube are moving too, Q34 and Q36 are replaced, power management DB4175 be replaced, I …
Today received a peer T61 IBM notebook standby machine; been repaired, the first observation of what are moving, visually dynamic power connector of the first P-channel MOS transistor, the upper and lower tubes are moving too , Q34 and Q36 are replaced, power management DB4175 also be replaced, I looked under powered on, no standby current, there – the thought is certainly open the main power supply did not come, and measured the Q34 control foot high, then down check him after several small components over the the DB4175 first 59 feet, that is here to open the main power supply, with the ball is a dozen high ping, open point bitmap ; This is T61 similar point, we will look at it
This is 59 feet of main voltage 20V, ah, thought the public point out how not standby it, the first 59 feet the VREGIN20 and back R522 connected voltage. Followed by investigation, trying to come up If the primary voltage coming, you should check the next level, 37 feet, he is no voltage, the problem is found along up the investigation, the first 37 feet are attached to the back of the R12O3. 10 ohm resistor www.nbdxs.com playing table under the value of 325, then change This should be good, energized measured or did not come out, depressed, is it connected to the line and 37 feet disconnected, has been here to check investigation did not detect anything out, well, first lay down the work, rest tomorrow, ah, still could not calm down, the next day I rest I come to work, must get him thinking about what should be public isoelectric point VREGIN20 this a problem, and open points bitmap, several points of the investigation and 59 feet connected to the back of the check suddenly found a no, R5
22 is not connected to the point
Turned and took the line to fly, Oh, actually bright, T61 IBM notebook standby maintenance troubleshooting, but have been thinking about how this point barrier will cause no current? After opened the drawing looked under the TH-DET signal is temperature control, strange, how thermostat will cause the current do?
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