• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Real Quick Question

I do not have a scope, I barely have a soldering station and 2 Millimeters. I have no formal training and have been working on this stuff for only 10 years now.

I googled protection relay for a Sanyo 2033 and it shows a picture of a relay with a clear plastic window but there is not one in this stereo.

I can not find a place to buy the service manual.
 
Last edited:
You should really be troubleshooting the actual problem instead of just changing parts. You need the service manual / schematic and a signal tracer or oscilloscope. There are some people who are skilled at troubleshooting without a schematic, but not me. I need a map to go by. I am just a hobbyist, not a professional technician. I have bought service manuals for all of my equipment.
 
I do not have that set of skills so I just have to install parts. Besides the parts are relatively inexpensive.

I changed the one main transistor and my next step is to change all the smaller ones.
 
Hey pioneer pro, did you clean all the switches? I don't recall you posting that.

I re-read your symptoms and it sure seems like a dirty contact or switch.

Is the left channel dead also?

There is a way to test the stk power packs but that would require reading the data sheet.

Before changing out transistors, I'd clean contacts and post symptoms again.

If the left channel is dead, post the voltage at each stk pin. Be careful not to short anything.
 
rickl said:
Hey pioneer pro, did you clean all the switches? I don't recall you posting that.

I re-read your symptoms and it sure seems like a dirty contact or switch.
Click to expand...
rickl

Yes, All Pots and Switches were cleaned and exercised.
One channel was dead while the other was crackley but they are both crackeling now.
I can't find the service manual anywhere.

I can do that and get back to you guys. Thank You
 
PioneerPro said:
I can't find the service manual anywhere.
Click to expand...

If you didn't want to buy a service manual, maybe the sanyo 2016 manual can help. It might be close.

Great news both channels are kind of working.

Did you compare the voltages with the stk datasheet?

It might point to a hint of the problem.
 
Last edited:
rickl said:
If you didn't want to buy a service manual, maybe the sanyo 2016 manual can help. It might be close.
Click to expand...
rickl,

The 2016 and 2030 are not similar based on internal photos on-line.
I can't even find a place to buy the service manual, no one carries it.
After changing the Caps on the main board both channels now put out sound.
Once again I will get my voltages and post them.

Thank You
 
redk9258 said:
There is a service manual for sale in ebay right now.
Click to expand...
Oh nice, $65.00 for a copy of the original. Very Very fair, I think I will buy two. Soon I will have $200 into this Sanyo that is worth $150.00

Here are my main board voltage readings from left to right. See photo for reference.

Yellow - 27 AC
Yellow - 27 AC
White - 0
Blue Black .062 DC or 14.8 AC
Black Black .034 DC or 7.68 AC
Blue Black .003 DC or .002 AC ???
White .035 DC or .001 AC ???
White Red .035 DC or 7.73 AC
Red .062 DC or 14.82 AC

Either this stupid receiver is ****ing with me or all of the sudden I can not read a Multimeter. I do not understand how these readings can be close to correct and everything but sound is working on this receiver.
 

Attachments

  • 1c837cd3-6910-42fe-a10b-95396c1b4c9b.jpg
    1c837cd3-6910-42fe-a10b-95396c1b4c9b.jpg
    127.2 KB · Views: 6
Someone mentioned that I should buy the Service Manual and if I do I should post it here to help others in the future.

Is there a specific place that these manuals are posted or are they just posted in certain threads about that make and model on those receivers?
 
whoaru99 said:
Except that the more you muck about unnecessarily, the more risk there is to unintentionally make it worse. There are many examples of good intentions gone bad in the AK annals.
Click to expand...
whoaru99,

You are absolutely correct but the only other option I am left with is to not fix it which means throwing it away, or I can find a shop that can fix it, but in my case there are none in Central Iowa and the value of the unit is not worth the repair costs.

This is where Audiokarma and the entire electronics repair community come into play.
 
I'd try to diagnose the problem first. Replacing parts and parts without any plan or goal, is not a good idea. You will end with dozens of parts you can't trust anymore. You can trust original parts, even if not working, they are fit the right way and PCB traces are not damaged or shorted. After an intervention, all kind of problems can show up, broken PCB traces, broken wires when moving the boards, parts installed backwards, replacement transistors with different pinout, and so.

I'd build, at least , a signal tracer, and try to follow the signal, sending it to a 2nd amplifier or powered speaker: (DC blocking capacitor can be 100V)

Also, following the signal path from the input connectors, painting the pcb traces with a marker, all the way to the function selector, tape montior switches, volume pot and so , is a good idea.
sonda_audio-2.jpg

sonda-foto_P1090325.jpg
 
I replaced all the small transistors in the main board and once again it made no difference.

One A733 replaced with a KSA992
Six A640 replaced with KSA992
One A1017 replaced with KSA1013
Two C2363 replaced with KSC2383
Six C945 replaced with KSC1815

All ten of these factory and replacement transistors are ECB Pinout.

I had all of these on hand from previous other jobs. No cracks in the solder, no broken traces, no disconnected wires no blown fuses, and all Caps and Transistors properly installed.

On to the last possibility in the main board and that would be the two main output transistors which are irreplaceable. By the way, one side heats up faster than the other side.

I am a firm believer that the most obvious problem is usually the correct problem that needs to be repaired. Many of you have worked on this receiver and have encountered this issue but for some reason no one recalls the fix. Once again the sound only comes on at the higher volumes and is staticy and crackly, the words are audible and unable to listen to and enjoy.

Thank You
 
Last edited:
elnaldo said:
I'd try to diagnose the problem first. Replacing parts and parts without any plan or goal, is not a good idea. You will end with dozens of parts you can't trust anymore. You can trust original parts, even if not working, they are fit the right way and PCB traces are not damaged or shorted.
Click to expand...

The problem existed before I started working on the receiver and it still exists so it would not be a new possible problem such as a loose wire or cracked trace etc.
 
Not sure what is where in this one . . . Are the main filter caps on the board or elsewhere, and have you checked those? A lot of times, if values have drifted apart, as the power supply drains, the difference in the pos and neg rails builds and can cause a thump.
 
PioneerPro said:
The problem existed before I started working on the receiver and it still exists so it would not be a new possible problem such as a loose wire or cracked trace etc.
Click to expand...
Anyway, replacing a lot of parts without a diagnosis can introduce more variables and more things you can't trust. The proper way to solve a problem is to trace the fail and narrow the problem to a small area. As you say, you already replaced many parts and the problem is still there. There are many ways to trace a fail. I'd start checking voltages and tracing the signal with a probe, sending it to a 2nd amplifier.
 
You must log in or register to reply here.
Back
Top Bottom