T61: No DC in light, no battery light, nothing.

[Bert Kwok]

I acquired a genuine 90W power brick because I foolishly metered the outside shell instead of the inside of the DC plug (I know, I know).
Anyway, I don`t want to junk this machine for the following reasons. Its more than up to the work I give to it. It has a T9300 and 8GB of quality DDR2, the clincher is that I have 3 9cell batteries, Lenovo batteries that cost me a fair amount.
It used to be a 6457-4UG, build date is 08/08 and I have owned it since new, still beating myself up for not extending the warranty after 3 years.
My wife told me it would not spark up and sure enough it will not. So the original cheapo 60W power brick that replaced my lost Lenovo brick is good for 20VDC. The newly acquired real McCoy 90W brick is good too.
I assume the fault will be fundamental, the DC charging circuit fuse, F2 if my initial searches are fruitful. I have not disassembled the beast yet but would appreciate some input. I lifted the keyboard to check if my missus was not telling me some important truth, no signs of spillage at all (i know, i know!).
I already have a 7A SM fuse that a kindly gent at a third party repairers de-soldered from a dead by spillage board for me today.
So for you T series owners am I barking up the right tree and for them that have replaced a DC in fuse, did something of a beyond economical repair nature cause it or did your laptop live happily ever after?

[RealBlackStuff]

Welcome to the forum.
Replacing a fuse is not the easiest, but certainly one of the cheaper repairs, IF that is the only problem.
Piggyback soldering it would be the way out.
What happens on only a (charged) battery (and no AC adapter)?

[Bert Kwok]

Thank you for the welcome Mr RBS! I have read many of your posts here in the past and gleaned much of use from this and the other place.
I don`t know for sure if any of my batts have any remaining charge. At times like this I wish I could rely on a second machine to check/charge them. If its the 7A fuse that serves the DC in I am hoping it serves the brick and the laptops own battery. I am two unlit LED`s short of any joy, the external power indicator and the (If memory serves correctly) bi-colour battery indicator, green for charged/orange for charging?
I have the gear and have soldered a few SM devices over time but admittedly it ain`t an easy task for the occasional job in ones home. The replacement fuse is about 3mm x 2mm. I would think to solder it on top of the existing fuse if indeed that has failed.
Now that I have the fuse I need to clear space and strip the machine. Looking at the Lenovo training vids it appears that nothing shy of a complete strip will reveal the fuses as they are on the underside.
I will be disappointed if the underlying cause of a fuse blow is failed regulators or other planar damage and doubt a repair would be economical. The existing planar should have been good for not having the nvidia problem as it was dated August 08 when I checked after installing a T9300 (on the GPU top).
If the planar is a gonna I will probably have to find an Intel GPU board, I would like the extra graphics power but can live without it.