Marantz 2500 o scope problems

[geigercountR]

I just got this lovely big receiver but it has a problem with the o scope. It seems like the scope works but only fills 1/2 of the CRT screen. I fiddled with the horizontal size and gain pots and cleaned them but it did not help any. Any of you experts have any ideas is it a bad board? I was looking into a 2110 tuner to use for parts but does the 2110 have any o scope boards that will fit the 2500 as I think the tube will fit but I think the tube is fine?

 

[jstang]

Is the scope trace properly formed...but just not the size or position?

I can only speak to the 4400....but one of my 4400s had a scope issue when I first got it.... but that was fixed by all the tirm pots on the scope board...

Do you have service manual for it? The 4400 service manual did a pretty good job of providing info to trouble shoot and adjust the scope.... at least enought to help me....

Watch out the high voltage can give you one hell of a shock....ask me how I know....

johnk

 

[geigercountR]

crt problem

Thanks John the trace looks ok to me but it is jammed into 1/2 of the screen. Maybe it is the tube! Which on has the high voltage on it so I can keep my tongue away from it?

 

[jstang]

Yea, good idea...keep your tongue away from it....watch out the high voltage can be found by other body part elsewhere in the chasis if you are not careful..:yes:.

 

[Musicalme]

You just got to be careful where you stick things

 

[Punker X]

Sounds a deflection transistor has gone out on the driver board. More than likely an open resistor or two. For piece of mind, all caps and diodes should be changed out in the High Voltage section of the power supply.

 

[jblmar]

You beat me to it Mike.

Ron

 

[geigercountR]

Hum

Thanks you guys, I am also getting a barely noticeable hum in the audio I guess thats also the electrolytic bad caps in the power supply?

 

[jblmar]

Thanks you guys, I am also getting a barely noticeable hum in the audio I guess thats also the electrolytic bad caps in the power supply?

With the volume turned all the way down?

If yes, it could also be a bad diode in the power supply.

Ron

 

[geigercountR]

Power Supply board!

Well I just pulled the power supply circuit board out and guess what I found? It looks like most all of the caps have been leaking and one transistor is blown on it! I think I just found most of my problems with the scope tube! Does any one know a good source for replacement caps? What's with the 3 lead caps as it has 2 big ones with 3 leads on them all the rest have only 2 leads one is a 2200 uF 50v and the other is a 470 uF 50v?