the part is C53 (.47uF-50V polarized) found between the collector and base of Q23 - part of the ASO in a KR-4070
(SM here on the AK)
I pulled a little aluminum electrolyte (this is on the 4070 in another thread that got seriously shorted out - it has all new silicon, caps and resistors) I replaced with the same, but 5-10 minutes into setting bias, a hum showed up and it shut down both channels.
trouble shooting found that .01 of a volt at a time the voltage for the differential inputs dropped and dropped (14v spec due to D1 Zener) and about 5.2v is goes fuzzy and by 5.1v its dark.
further trouble shooting, found that the base of Q23 was +rail which would turn it on, but the collector of Q24 was negative. This cap apparently went direct shorted, and its brand spanking new. granted, stuff can break, but before I put another one in (with ASO disabled it has been running outputs disabled, on drivers for hours to proof the system) I want to check the part number. consulting page 14 of the hymnal (aka SM) we find that C53 is kenwood part CE04AW1HR47M.
In the tuner for example, there are many of the same, but the part number (page 13 of same hymnal) is CE04AW1HR47CC.
I see that in the SM, the M suffix tends to mean 'mylar' but alas C31,32 are 1Uf 50V polarized and are C04AW1H1R0MCC. WTH?
am I dealing with typos or or there something special about this part?
also, WTH does C53 even do? In a similar location, on the screen print, is C52, which is a) not present and b) not in the parts list.
so obviously there are multiple revs in here (like R31-34 are used 220ohm, 5%, 1/4W) but I challenge you to find them in the SM or parts list. I wanted to know ifthey could be regular or fireproof, not finding any info, I erred on the side of safety...
thanks in advance....
(SM here on the AK)
I pulled a little aluminum electrolyte (this is on the 4070 in another thread that got seriously shorted out - it has all new silicon, caps and resistors) I replaced with the same, but 5-10 minutes into setting bias, a hum showed up and it shut down both channels.
trouble shooting found that .01 of a volt at a time the voltage for the differential inputs dropped and dropped (14v spec due to D1 Zener) and about 5.2v is goes fuzzy and by 5.1v its dark.
further trouble shooting, found that the base of Q23 was +rail which would turn it on, but the collector of Q24 was negative. This cap apparently went direct shorted, and its brand spanking new. granted, stuff can break, but before I put another one in (with ASO disabled it has been running outputs disabled, on drivers for hours to proof the system) I want to check the part number. consulting page 14 of the hymnal (aka SM) we find that C53 is kenwood part CE04AW1HR47M.
In the tuner for example, there are many of the same, but the part number (page 13 of same hymnal) is CE04AW1HR47CC.
I see that in the SM, the M suffix tends to mean 'mylar' but alas C31,32 are 1Uf 50V polarized and are C04AW1H1R0MCC. WTH?
am I dealing with typos or or there something special about this part?
also, WTH does C53 even do? In a similar location, on the screen print, is C52, which is a) not present and b) not in the parts list.
so obviously there are multiple revs in here (like R31-34 are used 220ohm, 5%, 1/4W) but I challenge you to find them in the SM or parts list. I wanted to know ifthey could be regular or fireproof, not finding any info, I erred on the side of safety...
thanks in advance....