Re: Need ESR values for 8200uf 50v cap
So two questions :
1) Is the esr expect to be higher or lower than that when measured at 100hz?
2) If that specific cap, as an example, read 0.08 ohms (twice the maximum), would it technically be considered "bad" or just out of ideal spec? I've posts where people consider anything above 1 ohm to be really "bad"....
jimkarl
Member
Last Activity: 05-23-2017, 08:47 PM
Joined: 07-21-2014
Location: baltimore md
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Re: Need ESR values for 8200uf 50v cap
They are marked Rotel with 9341 but my question is more general then specific to these.Leave a comment:
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Need ESR values for 8200uf 50v cap
Looking at power supply caps in in Rotel amp.
What is considered a good or ok ESR value for a 8200uf 50v Cap?
What would be consider a marginal or bad value?
All the esr charts I can find peter out at 4700uf.... -
Re: Troubleshoot Sanyo DCX-3300ka Amp section
Been a while for this post, but my IC501 finally came in. Replaced it and same problem. Hum (only) in left channel.
IC 501 pin readings
Pin Voltage
1 0
2 45.6
3 45.7
4 45
5 N/A
6 N/A
7 45
8 44
9 44
10 45
Triple checked the caps on that channel - all are good and I even swapped out the output ones just in case. Also triple checked the resistors. measured the TR501 transistor that feeds Pin 8. B= 12.4, C=24, E = 11.9 all similar...Last edited by jimkarl; 01-19-2016, 07:13 PM.Leave a comment:
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Re: Marantz NR1501 HDMI Board CHK CPU Error
How did you replace this C1604 capacitor? It's a ridiculously tiny surface mount. For a layman that's never dealt with surface mount component replacement, how would I go about getting that off the board and putting a a regular size 100uf cap down?...Leave a comment:
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Re: Marantz NR1501 HDMI Board CHK CPU Error
Does anyone have a service manual for this unit? I have one flashing in standby. Push the power button then flashes fast 5 times then back to a slow flashLeave a comment:
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Re: Troubleshoot Sanyo DCX-3300ka Amp section
even though I had checked C517 previously, I pulled as you suggest just to triple check - no change. Definitely a short in the chip.
No obviously substitutions as far as the sanyo pages tell me (whereas other STK model did have replacements. Pulled the chip apart but fair to say "no user serviceable parts here - unless you are working under a microscope LOL.
I have an overseas source a little cheaper then the one on ebay, but still will be in for $20 ($10 part , $10 shipping). I just...Leave a comment:
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Re: Troubleshoot Sanyo DCX-3300ka Amp section
You meant between pins 2 & 3 right?...Leave a comment:
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Re: Troubleshoot Sanyo DCX-3300ka Amp section
It's showing a short. that's in circuit of course, but the other channel IC in circuit doesn't show a short....Leave a comment:
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Re: Troubleshoot Sanyo DCX-3300ka Amp section
Since there's audio going into the chip, and none at either speaker or the headphone jack (which immediately follows, not seeing how the switch could play a role....Leave a comment:
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Re: Troubleshoot Sanyo DCX-3300ka Amp section
I purchased the entire service manual. Nothing more relative to the circuit. Just typical board layouts, parts list, tuner stringing etc. . Between pin 2 and WHAT? You left the 2nd pin # out to check against....Leave a comment:
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Re: Troubleshoot Sanyo DCX-3300ka Amp section
Unfortunately no detailed breakdown for the IC other than it's an STK-023. Nor datasheet to be found on the internet anywhere, including the manufactures I could find that still can source the obsolete part. How ridiculous is that?...Leave a comment:
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Troubleshoot Sanyo DCX-3300ka Amp section
Have a Vintage sanyo receiver with no audio/channel hum on left front channel. Traced goo audio from the preamp board to the amp board. Amp board schematic attached. Pin Voltages on the main Amp IC are (with right channel included as a comparison):
Pin L R
1 GND GND
2 45.8 22.9 Pin to 1000uf coupling cap
3 46.3 46.3
4 45.8 35.1
5 N/A
6 N/A
7 10.1 23
8 45.8 23
9 18.9 22.9
10 44.5 44.5
Good audio and voltage (12V) at the TR5 emitter output. But on the other side of C503 at input pin 8 of IC501 (STK... -
Re: kenwood TK-40 Output problem - need help with circuit debug
Got it. Already printed out the datasheet with the new pin outs.Leave a comment:
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Re: kenwood TK-40 Output problem - need help with circuit debug
Correct - I backwards got them....Leave a comment:
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Re: kenwood TK-40 Output problem - need help with circuit debug
I'm not seeing BC556 readily available on ebay in NPN format, so I guess I'll go with the 546 for those. For the germanium replacement I'll get BC546 PNP as you suggested. (though now I think they may be ok but I'm going to replace anyway since they are already out.)
R17/R18 are not fitted. Only 4 of the six listed .47 resistors are present. Those two that are missing are just a direct line back to the power supply main cap. I'm sure it was just another slight schematic variation. There seem to be several......Last edited by jimkarl; 04-27-2015, 10:41 PM.Leave a comment:
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Re: kenwood TK-40 Output problem - need help with circuit debug
Pulled Q3/Q5 and they both register as dead on my BK transistor tester. Checked Q2 but looked good so I put it back. Then checked Q4/Q6 Transistor tester and it registered it (strangely on two different b/c/e combinations) so not 100% sure they were good or not. These are PNP. Diode test with a multimeter shows only .174 on a couple combinations in one direction, which seems quite low? Also showed leaky on the transistor tester.
Did a quick goggle search for 2sc538A replacement and shows BC107/A157. A157...Leave a comment:
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Re: kenwood TK-40 Output problem - need help with circuit debug
OK - Replaced Q1 in the power supply sections and D4 on the Main Amp board - both broken due to my clumsiness. Did a complete re-measure all over and have the attached results. What I find interesting is the consistent 0volts across Left channel Q2e/Q4c and Right channel q7e/Q6c respectively. (Also Q9b&e which they all tie to) Are Q2/Q7 dead and emitters fried? Too low base voltage to turn them on? Something wrong in the Q9 circuit portion that they both tie to?
I can pull them and test but figured I'd ask...Leave a comment:
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Re: kenwood TK-40 Output problem - need help with circuit debug
Also you said "check R8" you mean for accurate value, or to note voltage? Just want to be clear.Leave a comment:
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Re: kenwood TK-40 Output problem - need help with circuit debug
Idle current setting circuit? do you mean the D2/D4 Diode that broke?Leave a comment:
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