03-15-2014, 06:35 PM
Okay!
I spent all afternoon replacing electrolytics in the 440-T. You haven't lived until you have removed a Fisher preamp board (several wires and grounding points have to be removed, then you remove four screws and pull the board) and then reinstall it. Good thing my 440-T parts set arrived today (and it is a rather ratty unit, but the faceplate is in pretty good shape)...it helped me confirm that I reconnected everything correctly on that board. (I would have drawn a diagram otherwise, if I didn't have another set to go by.)
The control amplifier board can be serviced...carefully...without having to be removed. It had no less than eight 1 uF radial lead electrolytics, and all eight were leaking electrolyte to a greater or less degree.
It still plays after all that, but the right channel still sounds muddier than the left.
I did miss four electrolytics in the audio chain - two 16 uF units in the output section, and two 1 uF axial electrolytics on the control amplifier board. I forgot to order any 1 uF axials, but I have some 22 uF caps to replace the 16 uF caps.
There is one lousy 4 uF electrolytic on the IF board, and two electrolytics on the MPX board. The procedure for those two will be the same as for the preamp board - several wires will have to be disconnected, four screws removed, and then the board(s) physically removed for service.
I did some looking this afternoon, and did not see my old plastic hex alignment tools. I am wondering now if they got lost over the past two decades. That, frankly, is very likely.
Well, I can get some more when I order more parts.
I spent all afternoon replacing electrolytics in the 440-T. You haven't lived until you have removed a Fisher preamp board (several wires and grounding points have to be removed, then you remove four screws and pull the board) and then reinstall it. Good thing my 440-T parts set arrived today (and it is a rather ratty unit, but the faceplate is in pretty good shape)...it helped me confirm that I reconnected everything correctly on that board. (I would have drawn a diagram otherwise, if I didn't have another set to go by.)
The control amplifier board can be serviced...carefully...without having to be removed. It had no less than eight 1 uF radial lead electrolytics, and all eight were leaking electrolyte to a greater or less degree.
It still plays after all that, but the right channel still sounds muddier than the left.
I did miss four electrolytics in the audio chain - two 16 uF units in the output section, and two 1 uF axial electrolytics on the control amplifier board. I forgot to order any 1 uF axials, but I have some 22 uF caps to replace the 16 uF caps.
There is one lousy 4 uF electrolytic on the IF board, and two electrolytics on the MPX board. The procedure for those two will be the same as for the preamp board - several wires will have to be disconnected, four screws removed, and then the board(s) physically removed for service.
I did some looking this afternoon, and did not see my old plastic hex alignment tools. I am wondering now if they got lost over the past two decades. That, frankly, is very likely.
Well, I can get some more when I order more parts.