Hello guys,
i could use some help on a marantz 2238bl that has no fm reception whatsoever, AM works though.
Someone worked on this before and I noticed that Q201 and Q206 had already been replaced with 2n5770 and bc549 respectively and q301 was replaced with a ksc1845. The only thing I get out of it is a whole lot of static.
I replaced all the electrolytics but although some were really in bad shape that didn't cure anything. I then swapped the whole front end with one from a Sony ST-313l that looks identical but still no improvement. I checked all the voltages and they look ok apart from Q301 that has 3.2V on its collector when it should be 0.7v.
Meters don't move at all, signal strength is at 1 and centre is a little off to the left. At some point I touched J109 with my scope (no signal on it at all but it made the meters moved and the static changed a bit. Next I actually attached J109 to the antenna input of my little sansui tu-505 and tuned it to a station, I got some buzzing from the marantz but could here the station very faintly in the background. When removing my scope i touched the metal shielding from the front end and the now the station sounded really clear, pretty strong and no more buzzing
. So to sum up my scope is connected to the shielding (no ground clip attached) and J109 is connected to the 75ohm antenna input of another tuner.
I know that's a lot of information but I wanted to be thorough, any suggestions would be very welcome.
i could use some help on a marantz 2238bl that has no fm reception whatsoever, AM works though.
Someone worked on this before and I noticed that Q201 and Q206 had already been replaced with 2n5770 and bc549 respectively and q301 was replaced with a ksc1845. The only thing I get out of it is a whole lot of static.
I replaced all the electrolytics but although some were really in bad shape that didn't cure anything. I then swapped the whole front end with one from a Sony ST-313l that looks identical but still no improvement. I checked all the voltages and they look ok apart from Q301 that has 3.2V on its collector when it should be 0.7v.
Meters don't move at all, signal strength is at 1 and centre is a little off to the left. At some point I touched J109 with my scope (no signal on it at all but it made the meters moved and the static changed a bit. Next I actually attached J109 to the antenna input of my little sansui tu-505 and tuned it to a station, I got some buzzing from the marantz but could here the station very faintly in the background. When removing my scope i touched the metal shielding from the front end and the now the station sounded really clear, pretty strong and no more buzzing
. So to sum up my scope is connected to the shielding (no ground clip attached) and J109 is connected to the 75ohm antenna input of another tuner. I know that's a lot of information but I wanted to be thorough, any suggestions would be very welcome.
. That does mean that it doesn't have quadradial jack.