Marantz 2245 voltage adjustment problem

j802 still disconnected ?
smoke from where ?
this is most odd .
Sorry I was away for one day, but I am back to the problem.

r734 is still off.
I think the smoke is coming from h806 - because it is shorted again.
 
Last edited:
good idea .. might not be so good here but worth a try .. need to regroup and report back with present status as i may have missed something
To summ up what I have done so far:

P700
c713 changed with nichicon 100 mF/50V
h 705/706 replaced by 2sc2240
h707/708 replaced by 1n4148
h709 replaced with 2x 1n4148 in series
r734 currently off

P800
c801/802/803/804805/807/810 replaced by nichicons. Polarity double checked
h807 changed with zener 6.8v/0.5W
h806 changed with 2sc2240 - burns when relay clicks
r804 burned so replaced with 10ohm/0.5W
Relay contacts cleaned

DB test is ok
 
check h01 h802 h811 h812

measure ohms between j804 j805 .
measure ohms between j803 and j804
measure ohms between j803 and j805
measure ohms between j803 and h810 emitter .
 
check h01 h802 h811 h812

measure ohms between j804 j805 .
measure ohms between j803 and j804
measure ohms between j803 and j805
measure ohms between j803 and h810 emitter .

j804 j805 - 12.4
j803 j804 - 6.6
j803 j805 - 6.5
j803 e h810 - 0.5
All in ohms.

But these values are with a new 2240 and i have not powered it yet.
For h801/802/811/812 I cannot say for sure but I think they are ok. Will double check them and come back
 
Last edited:
did you remove the relay to clean it ? if so check for solder bridges . check for solder bridges anyway .
Thanks Pete!
I have not removed the relay.
Since I am not so experienced at soldering, can you pls give me tips on how to check for bad solder joints and bridges?
I am checking at the moment and took some pictures. If you see sth pls advise.

IMG_20180720_231538[1].jpg IMG_20180720_231548[1].jpg IMG_20180720_231604[1].jpg IMG_20180720_231604[1].jpg IMG_20180720_231614[1].jpg
 
3rd pic .. 3rd solder pad extreme left and 4th solder pad . follow to past centre of pic .looks like they are bridged together .
 
I wonder if I should replace h801/802/811/812/813 with 200v/1A. I saw in an article that they are commonly replaced, so tomorrow I might go and get some of this type?
 
wont harm to change those .. what i am struggling with is that transistor burning up when the relay clicks .. i cant help thinking its a coincidence and just takes same amount of time as relay timing . disconnect j802 until this is fixed . and thinking about it also disconnect j801 . this will narrow things down somewhat .
 
Back
Top Bottom