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I have not got an oscilloscope but on a multimeter the pmslps4l (which becomes p5vs3_en) stays low . This signal feeds the S3 en signal for the 3v3 rail too . Bust mcp then. Which is bizarre as all this happened when I was working on the audio connectors with the board disassembled .

Thanks I wrongly assumed that active low in this case meant that the signal would pulse low and reset the MCP for turning on. The pwrbtn_l signal drops to 170mV or so when the pads are shorted.

Hello no luck getting the s3 rails up. seemingly the 3v3 and 5v s3_en lines come from the MCP and neither are high. also PM_RSM_RST_L is not going low. any suggestions for getting over this next hurdle are very welcome.

yes - I do have 3v3 at L7220! and the 1v05 s5 rail as well. that's really odd: I could swear that they were not there when I last tested - I wonder whether the board needed to be turned on to have the s5 rails and somehow I failed to touch the contacts correctly? anyway - great news. Now to...

it was the trackpad in the end. flex cable was fine. keyboard fine. no noticeable corrosion in the trackpad circuitry. but evidently something was wrong as the ONOFF line was not being brought low. but this is the board that keeps on giving! I've now tried two other trackpads in the device...

how can that be right? the keyboard connects into the trackpad, and the trackpad connects to the board. so if there is an issue on the trackpad board then that will affect the keyboard comms. as above - connector to smc_onoff_L is fine. cable tests fine too and of course I have tried...

I just tried the board in a new chassis and it worked fine. so either a keyboard problem or flex cable or trackpad. will narrow it down tomorrow.

Thanks The trace are fine. Each pin of the flex cable has continuity to its pair too . This is the second keyboard too.... kB connector is visually good under a microscope.

Resurrecting this thread, on R5115/6 I have the expected 3.42v/gnd on the pins. plugging in a keyboard and pressing the power button shows no change on SMC_onoff. is this a sure sign of a dead kb? manually shorting the pads caused a reboot. the board history is water (wine) damage around...

this board is back on the bench after the summer break. It's from my favourite workhorse of the last 9 years, so I'm keen to revive it. brief recap: board was working fine until I soldered the speakers back on to the board (the connector had ripped off years before). I must have knocked or...

Thanks for the reply. We all have to learn somewhere and this is one of those boards. Re the voltage on 3v42 - injecting 3.42v showed very low current draw and no heat in any of the circuits. If there was a short (and it's measuring 83 Ohm whereas on other boards the 3v42 to ground is much...

No idea. Something must have been conductive to cause the fried board. But when I measure the resistance across the remnants of the paint it is not conductive. I've removed all the paint from the board and lifted and cleaned all the components with trace of paint on them apart from the usb as...

I have an 820-3208a with paint spill in a bunch of places. Seems to have got everywhere and although it was non-conductive paint, the board had serious damage around the pp3v42_g3H area on both sides of the board. the stop mask has evaporated in a number of places; but I have rebuilt the whole...

U6410 is on the main board .

Duke - the flat cable is in for testing the green->orange. I am currently testing without any IO board, injecting voltage directly on the PPv5_S4RS3. the audio chip gets extremely hot. I will test U8080 again.

moving on from the misunderstanding issue, I powered the board up once again this morning and started testing the rails again. I no longer have pp5v_s0. pp3v3_s0 is present. as pp1v5_s0 and pp1v05_s0. vcore is not present. the dcin board gets very hot. 60 degrees generally although far...

pp5v_s4RS3, as referenced (incompletely) above. I am not testing it on J9500. As above I am testing it on the IO connector that one cannot access without removing the flat cable. J7000. It is supposed to be present on pin 3.

with the flat cable in situ I can see that the charger goes from green to orange. therefore am confident that I have a working SMC and 3v42 + PPBUS G3H are good. to test for S4R3 on the IO connector you have to disconnect the flat cable. so power off, disconnect flat cable, power on. test...

flat cable wasn't connected (can't get to the S4R3 pin on the IO connector with the flat cable on). tried a number of IO boards (three now). they all have green->orange but no fan spin. Test voltage on PP5v_S4R3 on the IO connector and the chip on IO board goes up in smoke. I can't work...

I had a rain damaged 820-3437b in the last few days. no obvious problems/corrosion on the board, there were some s0 rails present but no vcore and no fan spin. on testing I found that no pp5v_s4r3 was present on the dcin connector, so replaced that. Then U8080 got very very hot. Replacing...