Bit of an update. I have checked the tracks on the board and some of the tracks have had repair work done and are a bit shabby, one even has a wire soldered to it and is soldered further down the track to make continuity. However, that same track is shorted to it's adjacent track where an attempt at repair work has been attempted. Hope everyone's following this lol.
    Anyway, one track is connected to the Collector of Q7 and the Base of the main output Q2. The other track is connected to the Ground wire terminal in which one of the filter caps connects to and the other end to R32. I'm pretty sure they are shorting to each other where the attempted repair is, as there are a few dodgy blobs of solder, but it's hard to see them touching even with a magnifying glass. How I've established a short between the two tracks is I did a resistance test between the two tracks and there is continuity. Am I correct in assuming there shouldn't be or are these connected to each other further down the line anyway? Either way I'm going to try and desolder the dodgy area to separate the tracks there. This just could be the whole problem! 

Hey no probs G1.
:tu:

Yeah probably. Sorry if I don't use the correct terminology here and there, I am  English and guess you good people are American? Therefore I may explain things a little differently. 

That's right Enzo, When I refer to the "main board", I mean the board with all the transistors on, Q1 to Q7 on the schematic. So I disconnected the wires that lead from the filter caps to the board (I de-soldered them at the board). The fuses didn't blow when I did this, so I'm pretty confident everything is good to that point at least.
      G1, I am confused why you say that "leads you to the opposite conclusion", as the fuses are before the caps, so if the caps were shorted, surely the fuses would still blow?   

Rightio Enzo, for now then,I will check all traces and solder joints on the power supply board and wait patiently for you or other replies. Thanks for checking in.

Help!!  :loco

Ok, thanks Enzo and Galaxiex, and indeed Fahey, I realise how the lamp works and that there is a lot less current going through the circuit, I was just concerned that it still may burn something out after a while. However if you boys say it's ok then I'm with you all the way and will defo use the lamp limiter. I really appreciate all help given here. I have the lamp limiter and am keen and ready to go!

 JM Fahey, you are right the numbered resistors are no use without schematic, doh sorry about that, I actually have the schem too and didn't think to put it up. Also thanks Jazz P Bass for posting it. Any ideas at all. Also yes JM Fahey I have read about the light bulb tester, I will build one, but am a little concerned that if I use it, there is still current getting to the rest of the board etc, wouldn't this still do some damage to components?

Hello everyone, this is my first post on here. Sorry for it being long winded, but I want to try to give you as much info as poss.
  I would appreciate some help/guidance for my HH MA 150. The problem is, it blows both fuses instantly. I have checked the output transistors, they are fine, and I even disconnected them from the main board in case they were shorting to the chassis some how, but fuses still blown. I am confident filter caps are good as I disconnected the power leads, (the wires from the caps to the main board) and this time the fuses didn't blow. So I assume everything upto there is fine. I then checked all components on the main board, There were many problems, most transistors were faulty,I replaced Q2,3,4,5,6,7 (  these were all faulty when checked out of board too), also many resistors were out of spec and there had been a burn out around  R 22,24,28, one of those 3 was totally burnt black but I can't remember which one. I replaced R4,13,19,20,22,24,26,27,28. I was confident the problem would now be solved, but no, the fuses still blown. I also checked all diodes and they are fine. Any help would be very much appreciated as I am now stumped.