Marantz 4230 Repair Question

[Theoberheim]

OK, I just picked up a 4230 of the ol CL....everything worked fine at the gentleman's house. He had it hooked up to a nice set of Ohm Speakers:thmbsp: Everything worked, all lights worked, no scratchiness when tuning, it was perfect:yes: .

Now for the dumb-ass part....

I brought it home, hooked it up to my speakers, turned it on....and POOOF, all lights went out, and smoke was rising form the back of the unit.:tears:

I am trying to figure out what happened. I am an audiophile...not an electrician.
I am usually good at making sure that red goes to red, black goes to black....when hooking up speakers. To that end, if I reversed the red/black...would that fry my system like it did?

It may have been a problem with my power plug surging at the precise moment I turned the power on. I do not know.....

Does anyone know if I just blew the fuse? or am I completely jacked?

It is/was a nice one... a 4230 w/ wood box.....

 

[mikey3117]

I think I know what seller you are referring to... He listed a Marantz 2230 a few days ago for $53. I contacted him and he said it was in "good" condition. When I got there, it had a bent case with paint on it, deep scratches on the faceplate, filthy, etc. I passed... He had a pair of Ohm F's near his fireplace, and he was surprised that I knew what they were! He was a nice enough guy, but my impression was he tries to pass on equipment to the next guy at a profit without doing anything to the equipment when he takes it in! I at least clean them up, clean the controls, replace bulbs, etc...

Call Doug at Audio Specialties @ 503-257-3206. He will fix it for you reasonably! He's a great guy!

 

[Detailman]

Have you checked the fuses?
First thing to do.
sounds like something shorted out, hope you unplugged it quickly.

 

[jasong]

That's harsh. :\ Check the fuse first, but that generally doesn't sound good.

 

[Theoberheim]

mikey3117,

Yes, it was that guy. He had some nice Marantz units among others. A 2230 that was in absolute perfect condition. Still had the clear plastic covering over the faceplate. The Ohm speakers were absolutely amazing. I will definitely put those on the wish list.

At any rate, I called Doug. I will be bringing it by Saturday...If I cannot fix it up myself.

I did replace the fuse. It powered back up.....however, it did blow again.

At least I know that the unit is not dead. It did end up sideways during the car ride to my house. A wire might be making contact with something. I do not know. I will have to take it out of the box and see. If I cannot fix it... to Doug we go.

Thanks for the tips guys.

 

[HAL9000]

i just repaired mine.
it was in bad condition. very dirty.
one channel was blown out.
LOOK at the fuses!!!. is the 10A burned out. if yes...
one of you amplifiers is shot.





i replaced two power transistors.
two drivers
two pre drivers
1 diode
two emitter resistors.
one normal resistor.
and the capacitors

+- 1.5 hours of work

but i sounds great!!!

 

[jasong]

i just repaired mine.
it was in bad condition. very dirty.
one channel was blown out.
LOOK at the fuses!!!. is the 10A burned out. if yes...
one of you amplifiers is shot.

i replaced two power transistors.
two drivers
two pre drivers
1 diode
two emitter resistors.
one normal resistor.
and the capacitors

+- 1.5 hours of work

but i sounds great!!!

Hey HAL, I'm working on a 4230 now (waiting for some caps) that had a problem with stuttering distortion in the right rear channel. I have a thread up about it. Feel like having a look at the thread? I'd like to get your input on what else I need to look at and/or replace besides caps.

 

[morgan]

If the receiver had a 10 amp fuse installed, and it blew----------Lord knows what may be fried. I would guess that the line fuse must be much lower amperage than 10 amps!!

 

[Fred Longworth]

Shorted audio output transistors most likely.

Most common cause: tiny stands of speaker wire bridging across between the plus and minus leads of the speaker cable.

Fred Longworth

 

[jasong]

Shorted audio output transistors most likely.

Most common cause: tiny stands of speaker wire bridging across between the plus and minus leads of the speaker cable.

Fred Longworth

Hey Fred, I'd sure appreciate your two cents on my 4230 repair thread...

 

[HAL9000]

okee do this.

take some folie (metal paper) turn it around the fuse (blown doesn't matter)
set the 4230 on 4 channel mode.

NO SPEAKERS!!!! NO NO NO NO!!!!! SPEAKERs.
only headphone.

switch it on. and look wat is burning.
you should here a HUMM sounds at the broken amp...
(i think rear)

BE CAREFULL!!! . switch it on for a minuite.. :thumbsdn: :tresbon:


i didn't saw anything broken in my 4230.


OOH YES look at the power transistors C789. look for cracks!!!
if there is a crack!!. replace it immidiatly


jasong can you give me a link??

 

[HAL9000]

the result..

 

[jasong]

okee do this.

jasong can you give me a link??

Sure can!

http://audiokarma.org/forums/showthread.php?t=105031

 

[Theoberheim]

I purchased a few fuses. Powered up ok. However, I hooked it up to some speakers and tried it out. Rear Left and Right speakers were OK. Front Left was OK....but the Front Right had a bit of a hummmmm to it. I took it to Doug (thanks for the tip). Nice guy. He had all the lamps I needed to fix my Yamaha CR 1020... and my new Marantz Model 5220. I cant wait to get my quad system up and running.

 

[HAL9000]

i have the marantz 4400 and the 4230
i have had evereything of the quad line.

4220 4240 4270 4300(broken) 4400X6 times

 

[jasong]

i have the marantz 4400 and the 4230
i have had evereything of the quad line.

4220 4240 4270 4300(broken) 4400X6 times

I must say I'm jealous of your 4400s. :\

...do they all have decoders?

 

[Fred Longworth]

Warning!!!!!

DO NOT -- I REPEAT -- DO NOT DO THE TINFOIL AROUND THE FUSE THING THAT HAL9000 IS SUGGESTING!!!!!!!!!

If you have shorted output transistors, this will cause the problem to spread to more components than are currently damaged. It may blow out the rectifier bridge. Moreover, if the bridge goes, it may damage the power transformer.

CAUTION!

Fred Longworth

 

[HAL9000]

I must say I'm jealous of your 4400s. :\

...do they all have decoders?

no, i have all the decoders here.
SQ1 SQ2 SQ2A+B and a demulator CD400D

but i allmost never use it..


i've sold all the green scopes 4400s
i have only one blue 4400. in top condition.

i working on a 4300. he want 400,- euro's for it.
it looks great . functions 100%.
still it is expensive..

 

[HAL9000]

DO NOT -- I REPEAT -- DO NOT DO THE TINFOIL AROUND THE FUSE THING THAT HAL9000 IS SUGGESTING!!!!!!!!!

If you have shorted output transistors, this will cause the problem to spread to more components than are currently damaged. It may blow out the rectifier bridge. Moreover, if the bridge goes, it may damage the power transformer.

CAUTION!

Fred Longworth

ofcourse not.
both ways of the output transistor are secured by resistors.
they will burn..

i have repaired over 12 quad receivers.
marantz 4220 4230X2 4240X2 4270X3 4400X4

the 4220 4230 4240 is low voltage.
you can easily look WHAT is buring. and asses the problem then..
:thmbsp:

 

[kcollins4]

Never bypass a fuse, especially one that is known to be blowing!