Dim Bulb Test on Pioneer Amp - Goes on slightly then out?!

[H2ohm]

Hi All!

I build my first anything today - the Dim Bulb Tester and it works.

Other than still trying to find the right switch and figuring out the 3, 12 pin configuration 3P4T (which one is pin 1 and or pin A), I think my relays are fine as I measured ohms across the coils.

Anyway ---

I have tracked down two resistors in my Speaker Assembly for my Pioneer A-676 amp, they are R901 and R902; 100 ohm 1W each.

When I plugged in my amp to the Dim Bulb Tester, the bulb started to come on then it died out (150W bulb).

Would this be those shorted resistors?

I did lots of checking around the circuit board and even those SCR's for the 2 channels and they were reading 0.5 ohms so I think that means they are good. There are two green SCR's and two Black SCR's. I did this with the power off or course.

The power circuit board I checked the diodes and the resistors, caps I have no RSE yet to measure caps in circuit. They are all fine and the fuses are fine (getting newer ones as there is a slight discoloration on them on one half of the spring part that they are made of).

Very new to this and seek help from my fellow members who may offer assistance please!

Lastly, can I temporarily tie the leads of the good resistors over the bad ones to see if that will turn on my relays?

Thanks in advance!

 

[zebulon1]

The DBT will light brightly when a short is present in the set. Bright is bad. Dim is good.
When operating properly, when the power is applied with the set on DBT, the bulb will shine for a brief moment and dim to almost a glow. If a short is present in the set it stay bright.
What are you working on?

 

[H2ohm]

Thank you Zebulon - congrats to LV Knights too!

I am working on a Pioneer A-676. I was told to use deoxit and work it into the spearker switch, I did but stupid me I was doing it with the amp on and listening to the clicks to the relays! LOL Then they quit! The switch is in pieces a pain to get that out without the best component holder/puller when desoldering! LOL

So, I ordered a new switch but the pins A,B,C are more towards the center and mine is closer to pins 1-12. I went all over and I am out of luck. But, what I was thinking was running jumpers from this switch to the switch PCB and mount the switch in such a was to make it stable for use.

The amp is great the sound is very nice. What happened it got slight damage (my fault in shipping) and I am trying to fix the broken MC (j-b weld with do that) plastic around the switch - easy for that. But, the A+B would not work when I received it back just the A. Speaker B would work but I had to slightly turn it towards A+B.

My mistake for sure but a good time to learn but I got $50 into this (wrong parts ordered trail and error)! LOL

The hifiengine schematic does not label the pins but I sort of figured where the A+B is by following the the circuit, the trick is, what position is A+B: Pin C? Where Pin A is for speaker position A and pin B for B I am assuming!

Thank you for inquiring!