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DFL-FRP PCB REPAIRING
http://forum.hddguru.com/viewtopic.php?f=24&t=36804
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Author:  fzabkar [ May 15th, 2018, 3:04 ]
Post subject:  Re: DFL-FRP PCB REPAIRING

IRFR4105, International Rectifier, HEXFET, N-ch, 55V, 27A, RDS(on) = 0.045 ohm, 68W, D-Pak:
http://www.irf.com/product-info/datasheets/data/irfr4105.pdf
https://www.infineon.com/dgdl/irfr4105z.pdf?fileId=5546d462533600a4015356321a6f20ec

@Abdul Rauf, ISTM that you should have found your problem by now. :o :?

Author:  mad4hdd [ May 15th, 2018, 4:13 ]
Post subject:  Re: DFL-FRP PCB REPAIRING

fzabkar wrote:
mad4hdd wrote:
Its good idea ..... . he can also add a resistor (limiter) +5 to Gate.

The logic board drives the power board directly, without limiting resistors. ISTM that R5 and R7 are sufficiently large so as to limit the base current into Q3 and Q6.


Right , i was considering to test with an external power supply (isolated or without logic bord ). now my question is , if there is no +5 on SATA control pin then? and even he jumper it SATA pin to Gate, how can he get difference ? he must need to check logic board or he can try with external supply . in that way he has to use current limiter . kind of step by step testing .

Author:  fzabkar [ May 15th, 2018, 4:39 ]
Post subject:  Re: DFL-FRP PCB REPAIRING

My jumper runs from the +5V supply (ie the drain of Q1) to the bases of Q3 and Q6 via the SATA control pin. :?

BTW, there was a small error in my diagram (wrong transistor numbering).

Code:
                      +5V        +12V           +5V
                       +          +              +
                       |          |              |
                      .-.        .-.             |
               R1/R?? | |        | | R2/R9       |
                      | |        | |             |
                      '-'        '-'             |
                       |          |         G    | D
                       +----.     +-----------||-+  Q1/Q7
                       |    |     |           ||<-  IRFR4105
                Q3/Q9  |    |     | Q2/Q8     ||-+
  SATA/IDE    ___    |/     |   |/               | S   F1/F3
  power  o---|___|---|      '---|                |       _
  on/off             |>         |>               '----o_/ \o---o +5V output
  from        R5/R10   |          |
  logic                |          |                   poly-    o
  PCB                  |          |                   switch   |
                      ===        ===                          ===
                      GND        GND                          GND

Author:  mad4hdd [ May 15th, 2018, 5:20 ]
Post subject:  Re: DFL-FRP PCB REPAIRING

[quote="fzabkar"]My jumper runs from the +5V supply (ie the drain of Q1) to the bases of Q3 and Q6 via the SATA control pin. :?

possibly one out of these R1,R2,R5 could be bad . i did not check your diagram before . i was assuming SATA logic pin direct to Q1 ( G ) and that was not even gate . that is drain lol . i never seen this device and i assumed only .
mr Fzabkar i have a question in my mind and would like to ask you ... do you have same device right now with you? i mean its not possible for anyone to draw diagram and check connections of components on base of only pic . at least for me its not possible . please can you share what is magic or you have it in your hand ?

Author:  fzabkar [ May 15th, 2018, 14:44 ]
Post subject:  Re: DFL-FRP PCB REPAIRING

@mad4hdd, the power switching circuit is trivial. For me, the OP's photos are all that are needed to produce a circuit diagram that is adequate for troubleshooting purposes.

I agree that the OP should start by confirming that the logic board produces a logic 1 (+5V or +3.3V ?) at the SATA control pin. Then the unit should be disassembled, a jumper added to the power board, and the voltages at the marked test points (transistor collectors) should be measured. To make troubleshooting even easier, the OP can compare the voltages against the working IDE channel.

It goes without saying that the jumper should be removed before the unit is reassembled, and the unit should not be operated with the jumper in place.

Author:  Abdul Rauf [ May 15th, 2018, 15:43 ]
Post subject:  Re: DFL-FRP PCB REPAIRING

We are accepting the help from dolphindata technical support Dept.l

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