CTNovice
New Member
Hi guys,
I'm going to start off by saying that I am complete novice, and do not really have much experience in electronics repair. I am handy with a meter, have a decent soldering iron, and most importantly a can-do attitude.
Right, so I inherited a pair of 544's from my late father. Unfortunately one of them recently died on me, so I am wanting to have a go at repairing it. One of the output transistors for the mid/high section of the amp blew (TS444B) and I have discovered that the voltages in this section of the board are way off. I have attached a schematic, with the problem area outlined in red, and measured voltage written in, in red, as well.
While inputting my voltages on to the schematic, I did realise that the +5 supply is reading about 6v too high, so I will investigate that in the meantime. (hopefully I just wrote it down incorrectly)
For clarity, I have desoldered both output transistors (TS444A & B) so that I can test without continuously blowing the fuse. The measurements for those transistors are thus taken from their respective pads.
If anyone could shed some light, and/or point me in the right direction, it would be very much appreciated.
Happy to provide more info an measurements as required.
Thanks in advance and greetings from a not so sunny South Africa.
I'm going to start off by saying that I am complete novice, and do not really have much experience in electronics repair. I am handy with a meter, have a decent soldering iron, and most importantly a can-do attitude.
Right, so I inherited a pair of 544's from my late father. Unfortunately one of them recently died on me, so I am wanting to have a go at repairing it. One of the output transistors for the mid/high section of the amp blew (TS444B) and I have discovered that the voltages in this section of the board are way off. I have attached a schematic, with the problem area outlined in red, and measured voltage written in, in red, as well.
While inputting my voltages on to the schematic, I did realise that the +5 supply is reading about 6v too high, so I will investigate that in the meantime. (hopefully I just wrote it down incorrectly)
For clarity, I have desoldered both output transistors (TS444A & B) so that I can test without continuously blowing the fuse. The measurements for those transistors are thus taken from their respective pads.
If anyone could shed some light, and/or point me in the right direction, it would be very much appreciated.
Happy to provide more info an measurements as required.
Thanks in advance and greetings from a not so sunny South Africa.
