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Apologies for the misunderstanding. Q3080 is not shorted to ground.

Yes you are correct. Pin1 is 3.3/3.5v Pin 2 is 0.08v L3095: Pin1+2 = 0.08v Both L3095 and Pin 2 of F7140 are 144 Ohm to ground.

Thanks for all your help. Removed Q7130 R7120 now OL R7150 now 30 ohm to ground. DCIN now 14.4v Solid. PPBUS_G3H 0.1V Solid. PP3V42_G3H 3.4v Solid.

R7120 is 35ohm to ground R7150 is 34ohm to ground

Ok, brand new, out of the packet U7100 but back to DCIN at the DCIN board pulsing between 0-3/6v then gives up after 10 seconds or so. No PPBUS_G3H.

Didn't see your message until this morning. U7090 Pin1 = 1.23v Pin2 = 3.4v Pin3 = 6.7v Pin4 = 3.2v Pin5 = GND Pin6 = 14.4v Pin7 = N/A Pin8 = 14.4v All tested from the pins of U7090 Can't see any broken or corroded traces around there. Looks ok, right? Edit: Realising that PP3V42 is back...

PPDCIN_G3H_ISOL is present at a solid 14.4v R7005 tests fine at 10ohm D7005 Pin 1 = 0.08v Pin 2 = 14.4v Pin 3 = 14.4v Resistance to ground after these components is around 150k ohm tested at all points they connect to.

U7100 is still off the board but... Resistance to ground on PP3V42_G3H on 2MΩ mode = .445 I don't want to second guess anything so I shall now put back U7100 to test U7090 voltages of pin 6 and 8? Even when DCIN is all over the place with U7100 back on?

Nope not present.

So I'm now on my 5th successful board repair. 1 easy and the rest have been hard but I'm making progress and confidence is building. So this board is liquid damaged. There was a short on PP3V42. There were also shorts when testing pins on U7100. Rookie mistake but I didn't note down the pins...

FIXED! Thanks to everyone that helped. Especially you, Jason. Much appreciated! That final post lead me right to the cause. I have learnt loads from this. Importantly, I have proved to myself that my soldering and hot air skills are up to the job. I still don't get any reading from testing...

Cheers, will do in the morning.

Although very much a beginner, I have used a multi meter many times before. I'm confident that I'm using the meter right and looking at the right thing on the board. I am definitely pushing the limits of my electronic knowledge though. Hence coming here. So I have traced out with my finger and...

Have always been testing from the pins. Just checked at higher zoom and no line breaks. Continuity confirms this also, tested between pins and pads and every combination.

Ok, so I retested the continuity. Same results. Pin 27 has continuity to C7020, C7022 and R7022 which tests correctly @ 10ohm Pin 28 has continuity to C7020, C7021 and R7021 which tests correctly @ 10ohm Pin 17 has continuity to C7050 and R7052 which tests @ 0.3ohm, schematic says 0...? Pin...

Tested again just now. No reading between Pins 17 and 18 or 27 and 28. So a break in the current sensing circuit then? Again, apologies for the balls up and appreciate the patience.

Sorry, my bad, lack of experience and lack of decent, unbroken sleep meant I ballsed up the terminology. Pins 27 and 28 have continuity to R7021 and R7022 are correct at 10ohm Pins 17 and 18 have continuity to R7051 (2.5ohm) and R7052 (0.3ohm) Any clues on ticking noise?

Thanks for the replies chaps. I've just had another go to be sure and it's definitely the same results as before. OL between those pins. I even changed the battery in the meter. So I understand the train of thought here, what will these results tell us? Any idea what the ticking noise is that I...

PPBUS_G3H = 3.6v while pulsing/ticking 11.65v when fan spinning PP3V42_G3H = 3.45v Constant U7000: Pin1 = 16.3v Constant - 0.1-0.2v drop when fan starts Pin2 = 16.3v Constant - 0.1-0.2v drop when fan starts Pin3 = 3.9v Constant - 0.1-0.2v drop when fan starts Pin4 = 3.42v Fan off, 0v Fan...

Thanks for the reply. Unless the donor U7000 is also faulty, no joy with replacement. Back to the same situation. Ticking persisted even with U7000 off the board. C7020 and C7050 don't test as shorted...