Repair Question: Holiest Grail

[cakeworks]

Hello all... I think it has to have been months since I've come this way after finding mysself with less and less time for my passion for tone 

But the other day my mate handed me his broken 'Holiest Grail' by EHX and said 'I broke it, see what you can do with it'.
He then went on to explain that he bought it in America, and once home visited our local  (and stupid) music store to find an adapter for it for Aus.
They plugged something in and it made a pop sound (through the amp I believe) and now it works not at all.

I took off the back for a tentative look and the pcb looks like the underbelly of a small computer motherboard!

It freaked me out and made me cry like a little girl all the way home (here) to beseech those of you with more knowledge than I as to what it may be... and if it's fixable...

I did as much research I could as to possible adapters that may have been plugged into it... and i'm guessing either it was a holiER grail adapter (18V c) or perhaps a 9V with an AC output.

By the way it normally takes 9Vdc.

Could anyone shed any light on this for me please?

[GREEN FUZ]

First thing I`d do is look for any obviously burnt out components and replace them. You might get lucky and find that it needs minimal work.

[cakeworks]

Thank you green fuz,

I had a look and on reasonably close inspection i could find no burned components, bulging caps, or suspect joints...

Any other suggestions?

[MarcoMike]

maybe there is a protection diode at the DC input... that would be the one to check

[axg20202]

+1 My money is on that diode. A well-known music store near my home did the same thing with 3 Pulsar pedlas - I laughed so hard I nearly cried as they failed to learn from their mistake after breaking 2 pedals right in front of me. I can understand breaking one like this but to break 3? Haha! The boss strolled over and gave the pair of half-witted shop assistants a good bollocking for it. You just can't get the staff.

By the way, don't be tempted to just pull it out and jumper the pads - that diode did not die in vain.