Discussion in 'Yamaha' started by rottalpha, Dec 11, 2017.
will scan it for ya
Those are nice heatsinks What will special permission cost me?
makes a good Sunday afternoon read,
or if you were to rebuild your B-1, this probably has more info than other places on the net....
I had a hard time finding info on B-1 rebuilds when I decideed to take on the "quickie"
I am thinking maybe you could find out for us if those C rank SK180s of yours need further matching
In the meantime, "technical" details of my patented heatsinks are somewhere on the first page of this thread, in my response to Bratwurst.
Thank you Pete,
Am waiting for some parts and should be firing up the beast soon.
I have just completed the power supply boards 1&2.
Will let you know how I go
I also had a faulty MPSU60 on the power supply board 2 which I replaced this with a MPSW92.
Had to cut the heatsink for it, it is not much space in there
that would work.
Well, the capacitor kit from Clinic is in. I have finished the power supply boards 1&2. A quick test and the-200 volt and +40 are showing up nice and steady on the power supply board #2. Also managed to adjust the 12v, -25 and +25 on power supply board #1. I have a weird issue though. When I turn off the power switch the amp stays on for few seconds. Then turns off. Not sure what to make of it.
I checked the switch and the connection with the UC-1 and found no issues.
That main caps kit sure looks nice.
I think you are on the right track with troubleshooting. I would look at the switch and the protection circuit, including that solenoid.
the question I have is how were you able to adjust the voltages if the power turns off so quickly??
FYI, I powered averything up with a DBT and a variac, all the way to the driver boards.
I think the power switch may be the culprit.
When I turn the power ON remains on, but when I turn the power OFF just lingers for a couple of seconds before the power cuts off.
The 3rd protection board is in, now the real fun begins...
Say a prayer or two first, then watch those test leads.
What's taking so long
Now I get to ask that question
Well, the protection test went well last night.
Just finished the filter board.
Used 2SC1815 and 2SA1015 to replace the C458 and A763 transistors. Still need to source the relay.
Also replaced some of the ceramic caps with silver mica.
Pondering now on the first drive board.
man that driver board looks roasted
There are 2 types driver boards out there in B-1's, the more common light coloured ones and the rarer dark coloured ones.
so he must have both, because look how light color is the one behind
Btw, there are at least 4 different B-1 iterations/updates faded on rear panel variations I seen so far
The photo was from late last night and lighting was not ideal.
VintAge is right, there are 2 type of boards and I am using a light one for the filter but dark green for the driver
Here is a better shot of the driver board.
Thank you Pete for your help with the heat sinks
to me your driver boards looked diferent from eachother. I do not think is the lighting and I am not looking at the filter board...I am looking at two B-1 driver boards.
Just an observation...
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