Help with my Marantz 2600

zeprok123

zeprok123

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After buying this Marantz I had a local tech replace the fan, cord and clean it up.
It was working when it was returned to me and tech also mentioned the dual filter
caps don't have lots of life left. He wasn't able to address the issue of the tube not
focusing correctly that I mentioned. Hard to believe that was almost 20 years ago and I haven't used it since.
Recently I went ahead and replaced all P800 caps with same value that were on board voltages were increased.
Also the 3 regulator transistors Q801,803,805 were replaced with mje15032G
Parts were purchased as a kit and I believe they are good as I've bought other kits from same seller

100 watt Dim bulb test failed as bulb stays bright and pulses a bit and no relay click.
One video suggested removing wires j806 & j807 to isolate the amp boards of which I tried
and still no change. Bulb bright no click.
I removed the J801 wire harness from the P800 board and I heard the soft start click and bulb dimmed
a bit but no speaker relay click. I believe the j801 harness carries voltage to the tube filament and lamps.

Any thoughts would be appreciated
 
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Most likely it wants way more power to start up than a 100-Watt bulb will pass through without severe Voltage drop.

I don't understand, you have a Marantz 2600 receiver and no Variac to do things properly? This dim bulb testing is more akin to and old Philco stand up radio from the 30s or a five tube Zenith.

Find a friend who can help you out here and do it right. Most people would recommend like me to use it first before replacing parts to see what is really needed.
 
Jose Jimenez said:
Most likely it wants way more power to start up than a 100-Watt bulb will pass through without severe Voltage drop.

I don't understand, you have a Marantz 2600 receiver and no Variac to do things properly? This dim bulb testing is more akin to and old Philco stand up radio from the 30s or a five tube Zenith.

Find a friend who can help you out here and do it right. Most people would recommend like me to use it first before replacing parts to see what is really needed.
Click to expand...
Tried a 150 also same result. I have a variac just feel safer with the dim bulb. It's in not working condition now so listening is not an option yet. thanks
 
txturbo said:
Did it work before you did this?
Click to expand...
Yes but I used it only briefly and that was almost 20 years ago and at that time the filter caps I was told were going to not last much longer. I've double checked my work and when I replaced transistors I used new mica and thermal paste. I had to do some trace work but everything tests out ok with the multi meter.
 

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Use the Variac you have and bring up the Voltage to 30-35 Volts and start taking readings around the power supply and scale them to 120V operation. If the R801 resistor is between two capacitors and one side is 180V normally, you would see around 45 to 50V. The same goes for the 576V line. That is part of the scope section. I believe there is around +/- 92V on the large power supply capacitors. Scale them down also. You can measure them this way because they are part of an unregulated circuit. There may be a few more. I need to get back to making dinner.
 
What's the best way to measure at the purple wire for the 576V line and what's for dinner? I measured from one side of R801 and only got like
.50v then later checked and nothing. This is with variac at 30V
 
Just looking where to stick the probes as I know this is most likely beyond what I should be attempting but I've thought that before about
similar gear and somehow it worked out. If I can make someone chuckle along the way then all the better.
 
I have a cup, so I am ready to dig in. Look at the circuit board P800. We can start with the first four terminals on the six-way connector. There are three fuses. Check them all to make certain none are open. Next, let's go to the windings. The first at the top of the connector is a single leg off the transformer (for -576V). The second is common to all the windings. The third and fourth supply full wave rectification that the common is the center tap (for +180V). If the probe common is placed at the second terminal and you measure at the fuses or terminal before the diodes, you will see alternating current. So, between terminals 2 and 1, and the 2 to 3 and 2 to 4, you can increase slowly the Variac Voltage and see higher AC readings at these points. Don't go to high on the Variac, 30 is a good point to stop.

Before I go any further and you understand, let me know. Then we can move on and check the diodes and some of the capacitors. If you also want me to discuss this troubleshooting at a lower or higher dialog, I can do that also. You initially mentioned an issue with the scope, so I thought this a good place to start.
 
Jose Jimenez said:
I have a cup, so I am ready to dig in. Look at the circuit board P800. We can start with the first four terminals on the six-way connector. There are three fuses. Check them all to make certain none are open. Next, let's go to the windings. The first at the top of the connector is a single leg off the transformer (for -576V). The second is common to all the windings. The third and fourth supply full wave rectification that the common is the center tap (for +180V). If the probe common is placed at the second terminal and you measure at the fuses or terminal before the diodes, you will see alternating current. So, between terminals 2 and 1, and the 2 to 3 and 2 to 4, you can increase slowly the Variac Voltage and see higher AC readings at these points. Don't go to high on the Variac, 30 is a good point to stop.

Before I go any further and you understand, let me know. Then we can move on and check the diodes and some of the capacitors. If you also want me to discuss this troubleshooting at a lower or higher dialog, I can do that also. You initially mentioned an issue with the scope, so I thought this a good place to start.
Click to expand...
All fuses on the P800 are good. Just to make sure I am to remove the six-way connector and use + probe inserted into 1st terminal (purple wire -576) and - probe
inserted into the center tap? Same with the others? Thanks
 
Aren't they green, gray, blue, brown, for the first four? Then yellow, purple.

Q808 and Q809, the two diodes on the +180V circuit go to blue, brown, correct?
 
OH BOY! I see that now. I read the first two paragraphs so let me read into it a little. You understand what we are trying to accomplish, correct? The yellow is the ground from what I read. So it like upside down from what I initially gather? We'll get it though.

With the two connectors supplying the P800 board from the transformer, you can check those Voltages at 6-way the connector with the YELLOW as common. Is it easy to disconnect the connections to the power amplifiers to play it safe?
 
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I need to start making dinner so I will check in once in a while for the next hour. The rest will be simmering time!!! :) So I can read what you found out. Remember the ratio of line Voltage to the output of the transformer.
 
So I am using the yellow for my negative probe inside the plastic connector when checking each of the oscilloscope
connections with pos probe correct? Purple -576, Brown 180, Blue 180
 
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