5T-31 thermistors replacement help
- Thread starter N_Soph
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I got a Kenwood Ka-7002 and want to restore it. Most of the transistors on LC of the amp totally dead as well as the output transistors and some burnt resistors. I replace most of them but still need to replace one burnt out 5T-31. I keep searching and could not find the sub. for it or work around. The pre-amp work fine. I could use the preamp with other power amp for now.
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I think those are 5 ohm thermistors. Take a resistance reading from the good one to confirm.
Maybe this would work? https://www.digikey.com/en/products/detail/bourns-inc/BN-LG05Y5R0MYB/19241371
Maybe this would work? https://www.digikey.com/en/products/detail/bourns-inc/BN-LG05Y5R0MYB/19241371
I measure it one of them more than 100 ohm so it should be no good anymore. I will order it and try out.
No, I bought it like this way. The seller said LC had 45 volt DC on the speaker terminal. RC has 150 mV on speaker terminal. These components (red circle) were shot. VR4 was not working so it killed the output.
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ConradH
Lunatic Member
5 ohms seems an odd value for anything but a line inrush thermistor. It's in parallel with a 500 ohm adjustment pot so again, 5 ohms seems odd. What does it look like and is it purposely in contact with anything?
See post #11 here- Kenwood KA-6100 BIAS issues
See post #11 here- Kenwood KA-6100 BIAS issues
It touches KSA566 metal case. This picture shows it on the right channel. On the RC, both KSA566 and KSC680 still survice but on the LC both KSA566 and KSC680 dead.
I will replace them with MJE15033/MJE15032.
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It is a good new. If you found it, could you measure the resistance. Mine is over 100 ohm.
I found a picture of KA-7002 Amp board but it is different from my X07-0027-00.
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eizner23
Super Member
here is a 80 and 120 ohm NTC bias-compensation thermistor with approx same diameter https://www.mouser.com/en/ProductDetail/TDK/B57236S0800M000
Thanks, I got both channel going now with DC offset within 4 mV (SM allows 0-100 mV). Look at the relay, it is wired normally close circuit so when turn the unit on the relay does not kick in. I don't here the click. But if the circuit got upset (high voltage) the relay engaged which is opposite to other. Is it only for KA-7002?
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One channel got no sound last night which is on the bad thermal resistors. I swaps the thermal resistor from other channel and got the sound back. Measure both of 5T-31, it is 0.980 Kohm. Should this one be a good try for (NTCLE100E3102HB0A) 594-NTCL100E3102HB0A
It is just +46 volt and -46 Volt
eizner23
Super Member
Major sag...I would pull the outputs and remeasure.
Both channels have new MJ21194G/MJ21193G installed and MJE15033/MJE15032
