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Marantz 4300 Filter Cap Question

Richs_Trains

Richs_Trains

Well-Known Member
Hey guys,

Trying to re-cap my newly aqquired 4300, the existing filter caps are 20000uf 50v and the closest I could find that would fit was a 22000uf 50v. Is it okay to increase the filter cap to 22000? Just want to make sure before I change them out. As always ... Thanks Rich
 
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I used Nichicon Gold Tunes, rated at 22,000uF at 63V which are the same exact size as the stock caps and they worked great. I got them from AK vendor Parts Connexion - good people.
 
rBuckner said:
I used Nichicon Gold Tunes, rated at 22,000uF at 63V
Click to expand...

Randy, I got Nichion gold tune 22000uf 50v that are the correct size also, from Mouser. Now I just need to figure the best way to replace them.

Quick question... I have re-capped the left amp and the power suppyl, set the power supply voltage and the bias and dc for the left channel. The right channel is missing the p-700 board, the outputs and heatsink are there, but whoever worked on this before did not put the board back. I am able to power on and get audio from the left channel but it takes a good 30 seconds before the relay kicks in. It always kicks in and it sounds solid, it just seems to take much longer than any other Marantz I own (except maybe my 250M which takes a long time also), is this normal? Would not having the right channel P-700 installed make a difference? I am getting a P-700 from an AK member sometime in the next few days, so I guess I'll find out then. Any insight would be most helpful. Thanks Rich

4300_1_Pro.jpg 4300_2.jpg 4300_3.jpg
 
Relay should chime in within 8 seconds max. If not there could be something not up to par in the protection circuit.

On a side note, I'm pretty sure there are two 458 transistors tucked behind that black plate on the 700 board. You'll want to get those out of there!
 
petehall347 said:
monitor dc before relay . if in order check the timing cap in protect circuit .
Click to expand...

Pete, I am really a novice at this, where would I find the 'timing cap' and where are the 458 transistors that bryans12v speaks of. What would be the proper replacement for the 458 transistors, should I find them. Thanks Rich
 
start with checking each speaker output for dc voltage right after the relay clicks in .. the relay will click in below a certain voltage so if it is a dc problem you should catch it while its still dropping .
i am at a loss finding a schematic for protect circuit right now .
 
Okay, I found the 458's (H711/H712) look pretty difficult for me to get to without hurting something. Can't find anything on the 'timing cap'.
 
I wouldn't worry about the 458s just yet. When the time comes they can be swapped with the KSC1845FTU.

Let's nail down the relay issue. I don't have the schematic yet but the timing cap should be in series with a resistor on the base of one of the transistors on the power supply board I believe. I would heed peterhalls advice and monitor the DC to see if this is your issue before pulling anything. It would have to be monitored before the relay though until it opens then you can check at the speaker terminals.

I'll dig up the schematics here..
 
I would first make sure you've got power supply and rail voltages that are correct. Then make sure dc isn't where it shouldn't be and that the protection circuit is actually working properly.

Next make sure that 2x4 switch on the back panel is clean and moving freely. It looks like the timing cap should be C807 a 10uf 50v and it's probably well done. The power supply on all these 4270, 4300, 4400 should be the first thing to get reworked. Check all the resistors and diodes on PN01. Then backtrack from pin 5 of J801.
 
bryans12v said:
timing cap should be C807 a 10uf 50v and it's probably well done.
Click to expand...

I have already re-capped P-800 and that includes C807, but I have not changed out the 1000uf 63v axial that is on the underside. The power supply was a little high 35.7v, but iyt adjusted to 35v and held steady. I will try to check the DC at the relay and speaker outs. To check DC before the relay, where should I connect? Also, just something I noticed, once the relay clicks in, if I turn it off and wait a few seconds and turn it back on, the delay is about 8 seconds. I do not have the second P-700 board yet, and will probably wait to see if I get both channels before I go further.
 
Wow, Marantz trying to confuse a nooby, J036 pins are odd numbers only! Glad I referenced the SM before attempting to adjust the power amp!
 
When I check JN01 (I only have the left channel still), it is all over the map for a few seconds, the settles into 20mv counts down rapidly to about 8mv, fluctuates there 8-12mv, then relay kicks in at 8mv after 32 seconds. After the relay kicks in JN01 slowly decreases and then fluctuates between 3.0 and 4.0mv and seems to be mostly about 3.3mv. After about 5 minute it is down to 2.3mv on JN01.
 
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