Tweet
Hey folks,
You may never get the unfortunate opportunity to work on on of these PA type units if you're lucky.
At first blush it appears that the 2 main filters are bulged out & that looks like a fairly straight forward repair...right?!
NOT!
The power supply/output board is attached to the heatsink assy via the power transistors (nothing too odd there), BUT the screws that attach to the heatsink screw into nuts that are in slots in the heatsink which slide side to side freely with no way to secure them where they're supposed to be to align with the transistors. Not a huge big deal as you can get them positioned by using a 90 degree tool of some sort in the slot.
Still it takes extra time to do this to the 6 heatsink mounted transistors.
The next ridiculous issue is attaching the cooling fan to the heatsink nuts in the heatsink slots. The nuts that mount the fan to the heatsink also hold the entire heatsink to the rear panel. IOW, you have to properly orient the 4 nuts in the slots in the heatsink while properly aligning the fan to the heatsink nuts AND poking the screws thru the rear panel holes.
Fortunately, there were marring marks where the screws poked thru to the nuts and made impressions on the heatsink.
I aligned the nut to those marks & lightly hot-glued them in place. Yeah I know, when the heatsink gets hot, so the hot glue...frankly at this point I really don't care! There's only a few small dabs of it.
Wish I had thought to take pix, but was trying my level best to fight my evil ideations of throwing it against the wall (;-).
So just be warned to add extra time to this repair over and above what you would regularly charge to replace 2 filter caps. It's a real PAIN!
Thanx, g
You may never get the unfortunate opportunity to work on on of these PA type units if you're lucky.
At first blush it appears that the 2 main filters are bulged out & that looks like a fairly straight forward repair...right?!
NOT!
The power supply/output board is attached to the heatsink assy via the power transistors (nothing too odd there), BUT the screws that attach to the heatsink screw into nuts that are in slots in the heatsink which slide side to side freely with no way to secure them where they're supposed to be to align with the transistors. Not a huge big deal as you can get them positioned by using a 90 degree tool of some sort in the slot.
Still it takes extra time to do this to the 6 heatsink mounted transistors.
The next ridiculous issue is attaching the cooling fan to the heatsink nuts in the heatsink slots. The nuts that mount the fan to the heatsink also hold the entire heatsink to the rear panel. IOW, you have to properly orient the 4 nuts in the slots in the heatsink while properly aligning the fan to the heatsink nuts AND poking the screws thru the rear panel holes.
Fortunately, there were marring marks where the screws poked thru to the nuts and made impressions on the heatsink.
I aligned the nut to those marks & lightly hot-glued them in place. Yeah I know, when the heatsink gets hot, so the hot glue...frankly at this point I really don't care! There's only a few small dabs of it.
Wish I had thought to take pix, but was trying my level best to fight my evil ideations of throwing it against the wall (;-).
So just be warned to add extra time to this repair over and above what you would regularly charge to replace 2 filter caps. It's a real PAIN!
Thanx, g