no i conn the right+ to left - together hooked it up to the red multi conn. the black to the rca it read 10.5 i just testedthe output side that run to the speaker conn. was zero (onthe left of the picture WHAT IS THE B+ TERMINAL
The B+ terminal is the terminal you connect to the positive terminal of the battery. Measure the resistance between the B+ terminal and the shield.
There's no reason to connect the L- and R+ together. If you measure the resistance between them, you'll find that they are directly connected (internally).
There's no reason to connect the L- and R+ together. If you measure the resistance between them, you'll find that they are directly connected (internally).
where can i get this resistor. I like the cart info i will us it, im going to buildone with a street bike motor thanks alot
You need to measure the resistance between the B+ and shield to confirm that the transformer is shorted. If it's not shorted, you may not need the resistor.
As a side note, it would be better to measure the resistance between B+ and the non-bridging speaker terminals but there seemed to be a bit of confusion there so I suggested using the shield.
As a side note, it would be better to measure the resistance between B+ and the non-bridging speaker terminals but there seemed to be a bit of confusion there so I suggested using the shield.
If that's the case, the transformer isn't shorted unless the short is intermittant.
It's strange that you didn't get any reading. I would have expected a changing reading as the filter capacitors charged.
Measure the resistance between the chassis ground terminal and the L-/R+ terminals. You should read ~270 ohms.
It's strange that you didn't get any reading. I would have expected a changing reading as the filter capacitors charged.
Measure the resistance between the chassis ground terminal and the L-/R+ terminals. You should read ~270 ohms.
lets strart over the info i gave u was with a limited power supply i just hooked a car battery and it burned two small resistors next totwo blue ones. gold brown black brown and a small gold brown brown green resistor then blew the fuse as soon as the green light came on.
sorry man i did not mean to waste your time i was using a battery charger that was putting out 7.58 volts thats why it didnt blow the fuse and no ohm read. but it did not blow the resistor when i hooked it up in the car sorry for my ignorence
Did you have the 10 amp fuse in series with the B+ line?
Was the bottom cover clamped down on the transistors tightly when you powered it up?
Was the bottom cover clamped down on the transistors tightly when you powered it up?
Well... We have to find the defective output transistors. I didn't think any were defective before because it was not blowing fuses. It seemed like something else. When you powered it up without the cover, the outputs overheated and failed (or so it seems).
Measure the resistance between legs 2 and 3 of the transistors nearest the burned resistors. Do the same thing for the other 3 output transistors on the same side of the heatsink. 3 are likely to be 2N6488s. If so, the other 3 will be 2N6491s. The output transistors will be connected to the large resistors (leg 3 to the resistor).
Check the output transistors on the other side of the sink also. Hopefully, they survived.
If you find 1 (or more) that appear shorted, pull them from the board and re-check them. You need to be careful. These boards are somewhat fragile and the pads will lift/delaminate easily.
Measure the resistance between legs 2 and 3 of the transistors nearest the burned resistors. Do the same thing for the other 3 output transistors on the same side of the heatsink. 3 are likely to be 2N6488s. If so, the other 3 will be 2N6491s. The output transistors will be connected to the large resistors (leg 3 to the resistor).
Check the output transistors on the other side of the sink also. Hopefully, they survived.
If you find 1 (or more) that appear shorted, pull them from the board and re-check them. You need to be careful. These boards are somewhat fragile and the pads will lift/delaminate easily.
these resistors are connected to block half circle resistor same circuit as transitors. i checked the transistors and they read 1.5 ohms and decending the third one pin 2 3 read 100 ohms the fourth read .01 all the transistors seem ok it is the small resistors that are conn to KMPSA06 black
The 3 legged D shaped devices are small transistors (probably MPSA06/MPSA56).
There should be 6 total outputs transistors per channel. You only found 4?
Measure the resistance on the transistors again. Place one meter lead on the center leg of the output transistor and the other meter lead alternately on the other 2 legs of the transistor. Any that read near 0 ohms either way need to be pulled and rechecked. If you pull them, keep track of the locations of the 6488s and the 6491s.
Do you have a good soldering iron?
There should be 6 total outputs transistors per channel. You only found 4?
Measure the resistance on the transistors again. Place one meter lead on the center leg of the output transistor and the other meter lead alternately on the other 2 legs of the transistor. Any that read near 0 ohms either way need to be pulled and rechecked. If you pull them, keep track of the locations of the 6488s and the 6491s.
Do you have a good soldering iron?
it has 12 large transistors on each side and a bunch of little transistors the reading i got from the little ones that are circuited to the resistors are0.5 on each side on both The large resistors look good and i checked them
the 6488 three on each side read .06 .07 / .06 .07/ 99.8 198.( the side of the small burned resistors
the 6488 three on each side read .06 .07 / .06 .07/ 99.8 198.( the side of the small burned resistors
I'm concerned about the ones marked 2N6488 and 2N6491. Does your amp have those part numbers? They would be connected to the large resistors. Although we will have to check the driver transistors (D shaped) later, you must find and remove the blown output transistors first. Then you can check the drivers.
There will be one extra 6488 on one side and one extra 6491 on the other side. They will not be connected to a large resistor like the output transistors. The IRFZ44s in the power supply are not a concern at this time.
There will be one extra 6488 on one side and one extra 6491 on the other side. They will not be connected to a large resistor like the output transistors. The IRFZ44s in the power supply are not a concern at this time.
it has three 2n6491 on each side near the rca's the three next to those are 2n 6488 those are the ones i just gave you a reading on and an extra 7915CT next to the 6488 on each side of the transistor the other side was simular.
im gonna replace the burned resistors then start over withthe bottom on are they 1/2 or 1/4 watt
im gonna replace the burned resistors then start over withthe bottom on are they 1/2 or 1/4 watt
Ok, they are using an IC regulator (7815/7915) instead of a discrete regulator. The 'extra' 6488 and the extra 6491 would have been used in place of the IC regulators.
Replacing the resistors alone won't repair it. The resistors burned when something else failed (probably the output transistors).
You must find the shorted transistors.
Replacing the resistors alone won't repair it. The resistors burned when something else failed (probably the output transistors).
You must find the shorted transistors.
There doesn't have to be a particular resistance value between the legs. When transistors fail, they generally short (0 ohms). You're looking for transistors that have ~0 ohms between the legs.
Compare the side with the burned resistors to the side without burned resistors to see how they compare.
Measure the resistance between legs 2 and 3 of each of the 12 output transistors and post the values for each. To reduce the confusion, post the circuit board designation for the transistor then the resistance.
For example:
Q10 -- 200 ohms
Q11 -- 200 ohms
Q12 -- 200 ohms
Q13 -- 1 ohm
Q14 -- 1.2 ohms
Q15 -- 1.2 ohms
The resistance between legs 2 and 3 of the good transistors is likely going to be a rising value until the meter goes to OL.
Compare the side with the burned resistors to the side without burned resistors to see how they compare.
Measure the resistance between legs 2 and 3 of each of the 12 output transistors and post the values for each. To reduce the confusion, post the circuit board designation for the transistor then the resistance.
For example:
Q10 -- 200 ohms
Q11 -- 200 ohms
Q12 -- 200 ohms
Q13 -- 1 ohm
Q14 -- 1.2 ohms
Q15 -- 1.2 ohms
The resistance between legs 2 and 3 of the good transistors is likely going to be a rising value until the meter goes to OL.
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