Marantz SR5300

[limcc]

Got an old Marantz SR5300 receiver. It will switch off almost immediately after I switch on with remote controller. The LED is solid red and not blinking. I remove all add on cards and left only the main board, still the amp switch off. by removing the 2 ribbon cables, the amp stay on with display and I'm able to switch inputs, of course, theres no input but I can hear a click between inputs.

I suspect its the transistor that cause the problem but I really don't know how to check. they are SPA16P and SPA16N, I'm noob in transistor, could anyone guide me how to check for fault?

This is the Amp board
http://postimg.org/image/pupfigfn9/full/
This is Schematic
http://postimg.org/image/nbxhkt4r7/full/
Click the link for 3.5k RES, if image won't load, please see the attachment, they are only 2k res.

[Khron]

Re: Marantz SR5300

Step one: plug only one of the two ribbons at once time - that way, you can isolate on which "side" the problem is
Step two: after you find out which side is the "bad" one, try measuring the DC voltage between each output of the "bad" ribbon (see the right edge of the schematic) and a ground point. Sounds like there might be too much DC offset, which trips the protection.

[limcc]

Re: Marantz SR5300

I tried that before, either one will trip the amp to switch off.
I will try measuring the DC voltage, what value should I get from them?

[Khron]

Re: Marantz SR5300

Ideally, 0V; practically, under 50mV should be ok. But if it's enough to trip the protection, it may well be more than that.

In fact, nevermind that - i just took a closer look at the schematic, and it seems the amp supply rails are also in that pair of connectors, as well as the protection signal.

What i would do at this point, would be to try to follow the tracks for the B+ and B- rails. In a fortunate case, each of those would go through some of those wire jumpers on top - that would make the isolating of each channel, a lot easier If that's not an option, i'd start cutting tracks To re-join them, it should be enough to scrape off some of the solder-mask on both sides of the cut, and make a solder-bridge (if it's stubborn, stick a piece of not-that-thin wire into the solder).

The idea behind the jumper-removal/track-cutting is to have only ONE amp channel being hooked up to the power supply, at one time. Time-consuming, yes, but it's the option that needs the least amount of guesswork, and should give the clearest results

[limcc]

Re: Marantz SR5300

That looks like some major work for me. XD

I will give it a try, nothing to lose if I mess it up anyway.

Thanks for the replies, appreciated

[limcc]

Re: Marantz SR5300

Ideally, 0V; practically, under 50mV should be ok. But if it's enough to trip the protection, it may well be more than that.

In fact, nevermind that - i just took a closer look at the schematic, and it seems the amp supply rails are also in that pair of connectors, as well as the protection signal.

What i would do at this point, would be to try to follow the tracks for the B+ and B- rails. In a fortunate case, each of those would go through some of those wire jumpers on top - that would make the isolating of each channel, a lot easier If that's not an option, i'd start cutting tracks To re-join them, it should be enough to scrape off some of the solder-mask on both sides of the cut, and make a solder-bridge (if it's stubborn, stick a piece of not-that-thin wire into the solder).

The idea behind the jumper-removal/track-cutting is to have only ONE amp channel being hooked up to the power supply, at one time. Time-consuming, yes, but it's the option that needs the least amount of guesswork, and should give the clearest results

Follow up on my finding, gonna need your expertise again.

I took everything apart again. with all cables connected except the 2 ribbon cables, I inserted the card one by one, seems like some cards need other to be install before the amp will switch on. like the digital I/O card alone will prevent switch on unless the analog I/O card is also inserted. all went well until the video I/O cards--both S-Video and Composite--inserted, the amp would switch off. I then reconnect the ribbon cables, this time, only the right cable will trip.

So now the issue might be the faulty video cards causing the PSU to go crazy and shorted the output transistors. I don't need the video I/O but I guess the output transistors would not work unless all of them are connected. maybe because I had break the output circuit by removing one of the ribbon cable.

I only need a stereo output actually, although 4/5 ch would be great. I'm thinking how can I use the existing transistors to replace the faulty one and live with whatever ch have left. I mean, how to skip/bypass/re-route the channel without a transistor present?

[Khron]

Re: Marantz SR5300

Does the receiver work with the video i/o cards removed?

[limcc]

Re: Marantz SR5300

Does the receiver work with the video i/o cards removed?

It does, but due to the one of ribbon cable was removed, the Amp card wouldn't work so no output to speaker.

The good news is I finally make it work by re-solder one of the transistor--an IC, Linear Regulator, KIA7905PI. It was loose, turn out to be bad soldering/connect, this might had shorted the Video boards.

With the videos boards removed and that 7905 transistor re-solder, it finally work! I'm keeping my fingers crossed, hope it stay that way until I find a reason to upgrade.

Thanks again for the replies.

[Khron]

Re: Marantz SR5300

Oh Well, glad you managed to track down the culprit Cheers

[retiredcaps]

Re: Marantz SR5300

The good news is I finally make it work by re-solder one of the transistor--an IC, Linear Regulator, KIA7905PI. It was loose, turn out to be bad soldering/connect, this might had shorted the Video boards.

MaxxArcade is a member here and he does a lot of amplifier repairs/restoration and he finds a lot of bad solder joints.

http://www.youtube.com/watch?v=k0emWl8OxrA

Check out his youtube channel.

http://www.youtube.com/user/Maxxarcade

PS. I always wanted a Marantz, but never bought one.

[budm]

Re: Marantz SR5300

I would suggest that inspect the other solder joints for small ring develop around the joints, this is very common failure I saw since the 70's when I was working for the warranty station for FISHER, MARANTZ, SANSUI, PIONEER, PHILIPS, RCA, ZENITH, MAGNAVOX, and SONY. I never seen their board with nice shiny joints, there are always dull looking. The problem is still existing today.
http://s807.photobucket.com/user/bud...?sort=3&page=1

[limcc]

Re: Marantz SR5300

MaxxArcade is a member here and he does a lot of amplifier repairs/restoration and he finds a lot of bad solder joints.

http://www.youtube.com/watch?v=k0emWl8OxrA

Check out his youtube channel.

http://www.youtube.com/user/Maxxarcade

PS. I always wanted a Marantz, but never bought one.

WOW! Didn't expect the Pre/Power from HK can have such a shabby job in soldering.
MaxxArcade is a true expert, Hes way above my noob level. I'm like a elementary student watching a lecture by a professor.

I would suggest that inspect the other solder joints for small ring develop around the joints, this is very common failure I saw since the 70's when I was working for the warranty station for FISHER, MARANTZ, SANSUI, PIONEER, PHILIPS, RCA, ZENITH, MAGNAVOX, and SONY. I never seen their board with nice shiny joints, there are always dull looking. The problem is still existing today.
http://s807.photobucket.com/user/bud...?sort=3&page=1

Seems like most big brands with mass production lines are affected. and I thought they made better electronic stuff back then. then again, at least there's a way to fix if they gone bad, unlike the LSI circuit boards today.

======================================

BTW, I wonder if you guys can identify this cap(I think) for me.

Its a cap inside an old tuner power unit. Not really using it frequently, now its mainly a digital clock in bedroom.

[Khron]

Re: Marantz SR5300

That cap(?) should have some markings / writing on one of the flat sides. Any chance you could snap a shot from a more useful angle?

[limcc]

Re: Marantz SR5300

I will try to de-solder it and see if theres marking.
This thing is quite old, from 1990, I hope its still in one piece after I remove it. lol.

[limcc]

Re: Marantz SR5300

Looks like the cap lookalike is encase in silicone/rubber, shield from transformer heat?

edited:
ok, remove the rubber cover. I have no idea what is this.
Please guide me, like how to read the marking. also the black rectangular box which I guess its a transformer.

[Khron]

Re: Marantz SR5300

Get that rubber boot off it and see what the markings say

[limcc]

Re: Marantz SR5300

Get that rubber boot off it and see what the markings say

Done, Sir, please see my edited post.

[Khron]

Re: Marantz SR5300

If there's no markings on its back, then the "103" would be 10nF ("10" and 3 zeroes after that; 10000pF = 10nF). A quick google search of "KC103P" shows that it's supposedly a Murata 10nF 400v ceramic cap.

... Or you could've checked the schematic in the service manual

[budm]

Re: Marantz SR5300

http://www.surplus-electronics-sales...products_id=54

[limcc]

Re: Marantz SR5300

If there's no markings on its back, then the "103" would be 10nF ("10" and 3 zeroes after that; 10000pF = 10nF). A quick google search of "KC103P" shows that it's supposedly a Murata 10nF 400v ceramic cap.

... Or you could've checked the schematic in the service manual

That should be the one. other than the safety cert, KC103P is the only other marking, nothing at the back. Can't seems to find loose quantity on this cap, the only one listed on ebay is 25 QTY. I wonder if I can replace it with other make with "103" rating?

http://www.surplus-electronics-sales...products_id=54

Thanks, I suppose these website required min quantity and usually in dozens to hundreds. add in postage, it may cost more than my >20 years old tuner itself.

hope to find it in my local shop.