Pioneer amplifier A-205 Relay not clicking after a mistake i made

[redwire]

MEASURE the +/-15V rails and see if they are close, to tell if the regulator is still working. I think it's Q321/Q322 etc.
There is another +15V reg for the LEDs but you said they are working. If you keep getting zero then your multimeter ground might be wrong place?

[GraphicMan]

btw i did actually test the +15 on the connector and it is still zero with and without connect it to the button panel, always zero, is there any explanation for this?!

[GraphicMan]

update:
i just made a test on the original good resistor , i tried to blow it and it did not blow even at past 0.5A (about 2.5v or so) so over 1 watt
i did the same with the new ones, same performance, nothing happened (they both get hot to the touch at these ratings)

so i just replaced the 2 resistors, the relay kicked in, the amp worked and produced normal sound, the loundness also worked with its led, i can feel its normal slight effect on sound, so far so good,

does that mean that the 15v regulator is good? i think it is the one with a small heatsink very close to the mains, plz confirm
thanks a lot for your help, u guys are brilliant and so good

[GraphicMan]

Just look at the schematic and trace it. The +15V regulator isn't on this board PA board. Just test the two voltages at the connector...
You looking at the wrong page 19 again. On the schematic the two resistors are We got the info from looking at it like this:

thanks a lot , i found the page, is that the part number for the resistor f4r7j ?
i just got back from the market , the best i could find is 1/8watt 5.6 ohms, i barely found any 1/8 watt version, people also dont know much about fusible resistors, plz confirm the part number and if i can use the 5.6 ohms ones i got or not, ppl here say they use they tiny resistors at that low ohms as fuse anyways but i dont trust their knowledge
is it possible to make a test on one of them and see if they will burn or not at a specific mA ?

i already tested at the connector as u know, and there is only -15v, or did u mean to test after replacing the resistors?
can u plz point out to me where i can find the regulators u mentioned before?
thanks

[CapLeaker]

shorting the leads gave me 0.4 ~ 0.5 ohms, so it looks like the resistor is off, the unit is about 24 years old but rarely used
i have already tested q321 outside the pcb and it is good (is not that the regulator u mean?)
if the the regulator is gone then the resistors cant be a fusible i think, however the resistors really look like normal ones, they dont have the extra while band, what kind of amps should it blow at, i can make a test on the semi good one and see when it will fail with my volt station? i also need to know how to determine them fusible or not when i buy them to make sure, i looked that up and could not find an answer, plz let me know

attached page 19 from the service manual i have, it is terrible pdf, can u share the one you are looking at? i could not find any other better version, it is the only available one
thanks guys so much

Just look at the schematic and trace it. The +15V regulator isn't on this board PA board. Just test the two voltages at the connector...
You looking at the wrong page 19 again. On the schematic the two resistors are We got the info from looking at it like this:

[GraphicMan]

Short your meter probes together in resistance mode, you are likely measuring a couple ohms of lead resistance when checking R368 (4.7Ω). The values are marked on the schematic,I would just replace both 4.7Ω resistors

shorting the leads gave me 0.4 ~ 0.5 ohms, so it looks like the resistor is off, the unit is about 24 years old but rarely used
i have already tested q321 outside the pcb and it is good (is not that the regulator u mean?)
if the the regulator is gone then the resistors cant be a fusible i think, however the resistors really look like normal ones, they dont have the extra while band, what kind of amps should it blow at, i can make a test on the semi good one and see when it will fail with my volt station? i also need to know how to determine them fusible or not when i buy them to make sure, i looked that up and could not find an answer, plz let me know

attached page 19 from the service manual i have, it is terrible pdf, can u share the one you are looking at? i could not find any other better version, it is the only available one
thanks guys so much

[R_J]

Short your meter probes together in resistance mode, you are likely measuring a couple ohms of lead resistance when checking R368 (4.7Ω). The values are marked on the schematic,I would just replace both 4.7Ω resistors

[CapLeaker]

agreed , i will also measure the one giving me 8.8 ohms and let u know
how did u guys know the original value without seeing the color code which i did see and it is gold gold , violet and yellow (4.7 ohms)
i could not find it even on the service manual
another question, what if i did not find that fusible resistors, what can i use as a replacement?
thanks

The value of the resistor is in the manual. You just need to know how to read it. R367 & R368 RD1/8mmf4r7j is on the bottom of page 19 in the service manual. 4R7 = 4.7 Ohms. Plus it has to be a low ohms resistor in that location. So 4.7 Ohms sounds about right and it isn't an odd value resistor either. The RD1/8 is the wattage, so this is a pretty small resistor like the small ones in your post #5. The resistor is fusible because, if you bridge the connection instead of using the resistor, probably you burn up more chit you'd like to hear.

"i got it out and it is 8.6 ohms using 2 DMM, it has the same color code as its sister , should be 4.7 ohms,
now what?"

Now you need to find two replacement 4.7Ohm resistors 1/8 watt and replace it. Now if you lucky the +15v should be on one side of the resistor still there, it just didn't pass through because the resistor was basically open. If you are not lucky the +15V regulator failed and it needs to be replaced as well.

[GraphicMan]

i got it out and it is 8.6 ohms using 2 DMM, it has the same color code as its sister , should be 4.7 ohms,
now what?

[GraphicMan]

Lift a leg on both of the resistors and take an ohms reading. A 4.7ohm resistor reading 8.8 ohms is out of spec! A 4.7ohm resistor reading mega ohms is basically open. So both need replacing if that's the case.
A component is best tested out if circuit.

agreed , i will also measure the one giving me 8.8 ohms and let u know
how did u guys know the original value without seeing the color code which i did see and it is gold gold , violet and yellow (4.7 ohms)
i could not find it even on the service manual
another question, what if i did not find that fusible resistors, what can i use as a replacement?
thanks

[CapLeaker]

Lift a leg on both of the resistors and take an ohms reading. A 4.7ohm resistor reading 8.8 ohms is out of spec! A 4.7ohm resistor reading mega ohms is basically open. So both need replacing if that's the case.
A component is best tested out if circuit.

[GraphicMan]

Look at these resistors on the other side. I think R368 is 4.7Ω 1/4W fusible and is open, so the -15V rail would be gone.

yeah man i got the 367 out and it is giving me mega ohms!
shall i just replace it and test or there might be other issues?
thank u so much, u r really good

[GraphicMan]

Look at these resistors on the other side. I think R368 is 4.7Ω 1/4W fusible and is open, so the -15V rail would be gone.

btw the +15v is the missing, -15v is there as mentioned before

[GraphicMan]

I see many cracked (rings) solder joints that need to be fixed.

not as bad as it look but i can reflow all that once i get to the fault

[GraphicMan]

Look at these resistors on the other side. I think R368 is 4.7Ω 1/4W fusible and is open, so the -15V rail would be gone.

R368 = read 8.8 ohms
R367 when positive lead is on left, negative on right = short, when flipped the leads = open
shall i pull it out and test out?
many thanks for ur help

[redwire]

Look at these resistors on the other side. I think R368 is 4.7Ω 1/4W fusible and is open, so the -15V rail would be gone.

[CapLeaker]

Here is another high quality large pic for the whole pcb, hope that helps

I see many cracked (rings) solder joints that need to be fixed.

[GraphicMan]

Here is another high quality large pic for the whole pcb, hope that helps

[GraphicMan]

the Q321 was giving me some readings when tested on board, but one reading was suspicions so i thought i pull it out and test it, it looks like it is using old school base collector emmiter, the base was not in the middle, according to that it is testing ok 0.615 voltage drop on both E and C and nothing in reverse , also nothing between C and E, i am assuming it is good
i did not find R367 , just 367 and it actually giving me 34 vDC ! probably some caps are still charged, it is also giving me continuity, attached close up pics for the pcb, what do u think boss?

[redwire]

There are two +15V regulators. One is for the LEDs.
Check Q321 and R367 is 4.7R fusible, probably blown.