Question Marantz PM66 SE keeps blowing fuse

Hello All,
Hope your all doing well in these troubled times. I have just joined this forum to try and get some help with my amp (Marantz PM66 SE). Sorry in advance for the long winded post.

After having stored my hifi in the attic (I know BIG MISTAKE, I won't even say "hindsight an amazing thing" as a little logical thought should have stopped me from storing it in such a varied temp environment) anyway... connected it up and it actually worked for a minute or two. Had music coming out of both speakers, however one side was very low regardless of volume level. I messed around with the speaker plugs and still no improvement. Eventually, it just muted....no sound at all 😳 . When switching the amp on I could hear a click but nowhere as pronounced(loud) as it should be. This is a hifi system that has more value to me then it's actual financial worth and as I'm stuck in lockdown I thought I'd have a go at fixing it myself. I've been reading up 🧐 on capacitors, transistors, resistors...etc I don't have a huge amount of money to throw at it but I will give it my best shot to bring it back to life. I am your below average self taught fixer-upper, I have a multimeter, soldering iron, and a hammer lol 🔨

So one day I decided to open the amp... there were no obvious signs of capacitor explosions, however one of the large capacitors was very slightly swollen from the top and both of these large capacitors had a resin of some sort around the base. The pcb (think this is the sound board), from underneath, showed signs of burn in certain spots but not under the large capacitors. I immediately thought the capacitors had leaked out from the base so proceeded to remove them from the board. Having removed one of the capacitors I realised that the resin was not the electrolyte from the capacitor, it was some sort of glue to hold the capacitor in place :facepalm:. Kind of panicked and soldered it back in place lol.

After inspecting the board I noticed that the solder connections holding the three pin small transistor (D1508) had come loose. Re-soldered these on both sides, reassembled the amp, switched the amp on and a few seconds later something started to smoke 🔥 quickly switched off 🥵 . Plucked up the courage to switch it back on and the fuse (T1.6A 250V) blew. Upon further inspection of the pcb board I noticed one of the metal oxide resistors was reading 255ohms when it should be 330ohms. I'm assuming this is what heated up and started to smoke (total guess).

This is where I am at, obviously I could do with some help and advice. I'm trying to learn as much as I can before switching the soldering iron on. Also I'm 100% certain the capacitors (ELNA 10000uF 56V) need replacing but have no idea where to buy them. Some UK ELNA stockiest don't have the 10000uF 56V, I have found an ELNA 10000uF 63V on aliexpress but I really want to try to buy from UK so any ideas where I might be able to get these capacitors from?

I read up and watched countless videos on testing transistors (mosfet) and capacitors, thinking of removing the three transistors and the large capacitors from both sides of the board for testing. I am struggling with the markings on transistors :

One is marked as follows : A1256N with a R under the A and 6C under the N
Another marked as : D1508 with 6C above the D
the third is marked as follows : C3182N with R under the C and 5L under the N

Taking the first one as an example ...Is this a A1256N transistor? All the literature I have read state there should be two letters before the digital code. Also what does the R and the 6C mean?
Once I have understood/identified the components I will remove them and test them. Can anyone give me some advice on how to test capacitors and the above transistors. Info on google is so contradictory..one person says do this yet another says do that 😵

Am I going about this correctly? is there anything else I should check before taking the board apart?
If you have got this far with my post then thank you for reading, if you can give me some advice (other then buy a new amp or pay someone to fix it) that would be much appreciated.

Thank you & stay safe

bass out
 

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