I have changed the 4 output mosfets and everything now is working OK  Put in correct fuses also. Cost £10 in parts  Have ended up with some spares as well. Thanks everyone for your help. Michael.

Thanks Enzo,
                    I have ordered 4 output transistors. Will try them first. 

Hi,just wondering if the output trannies are shot and these are causing the fuses to blow. I have asked proel for a schem, but still waiting.
I am pretty good with multimeter reading schems ect.

Hi All,
         Our proel monitor keeps blowing all 4 internal fuses  The fuses are 4a on the high side and 2.5 on the low side. Can,t see anything burnt,so just wondered if anyone has any ideas. Michael.

Hi Folks, Can anyone tell me what Ic is in the input stage. Is it an LM 741. There does not seem to be a schematic available for these amps. I have hum from the amp output but nothing from the input. Seems to point the the opamp.Thanks.

Finally recapped my L5  Got the large caps from Mouser and the rest from Maplins here in the UK. I had to modify the large can caps as the screw contacts were out of line with the circuit board holes. I drilled two more holes in the board and carefully extended original holes with solder. Amp hopefully good for another 30 years. Big difference in sound quality,particulary the reverb. A big thanks for everyone who has given their opinions.

Hi just checked with Mouser,
                                          They stock a 75v 3000 mf cap Cat no 598DCM302U75AB2B I think they should fit ok as they are quite big. What do you think.  The rest of the caps i can get over here in the UK.

I have a Lab series L5 amp and would like to recap it. Anyone know where i can get the caps from,as no one in the uk seems to stock them. The two large 75v 3000mf are the ones i am haveing difficulty getting.