Recent content by paul_ral

Hi! I bought it from German ebay, I knew it is defective but i will try to repair. I think it is a rare piece of Pioneer tube tuners. I tested and it works only in mono mode. I search in MPX module and I found that 38KHz coil is damaged, all wires are cut inside and have no continuity. It is...

Hi! I bought it from German ebay, I knew it is defective but i will try to repair. I think it is a rare piece of Pioneer tuners. I tested and it works only in mono mode. I search in MPX module and I found that 38KHz coil is damaged, all wires are cut inside and have no continuity. It is...

Thank you sir!

Old thread but I need some infos about VR3 and VR4 trimmers. I have one SX-990 with damaged amp board, the previous tech tried to made a recap. I made another board and put new parts on it. According the schematic VR3(4) are 50 ohms but I have 500 ohms as old trimmers. Looking on post no 103 it...

I have -5V in TS403 base only, I must have -8 according the schematic. In DBT mode I have the right voltage. I ll check for a leakage in ac detect circuit.

Few milivolts. But I notice that big cans were replaced with 5pins Kemet at 24.000uf and the solders are not very good. The original filter caps are screws connected. Could be this an issue?

I replaced two 2SC1815 (no leakage) with new KSC1815 and no effect. It is still stuck in protection.

So, I put R411 back and I replaced 2TS403 (2SD545) with KSC1616A. Same behaviour, clicks on DBT and stay in ptotect mode without DBT. No DC Out voltages in both cases.

This will be my homework for tomorrow. Thank you, I let you know!

With R411 lifted relay click but only with speaker selector on A or B position. Power amp disengage after 4-5seconds from turn off

Yes

R412 is ok, around 1Mohm. I will try with R411. Thank you

On DBT all values are as in Service manual and the relay click. Without DBT no relay click, I have 56V on R413, resistor is good, 47kohms. The voltages on transistors are TS405: E=0, C=55V, B=-0.5V TS404: E=-0.5V, C=55V, B=0V TS403: E=0V, C=0V, B=-5V TS402, TS401 all pins 0V tested all resistors...

I have a beautiful 22AH380 on my bench with 22AH180 tuner and 22AH280 preamplifier, so entire Black Tulip line. I recapped all but I have a problem with power amp. As I said before, it was recapped, I changed two power outputs (2SD732 leakage). I can adjust DC out voltage and BIAS voltagen as in...

https://www.tme.eu/ro/en/details/ck-4857/ceramic-screwdrivers-trimmers/c-k/t4857/