blown two zx 700.5s and two deq 9200a

[Perry Babin]

Give me the DC voltage on all 16 pins of the TL494. Place the black meter probe on chassis ground. Place the red meter probe on the point where you need to measure the voltage.


Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:

[rolexcomm]

[QUOTE=Perry Babin;1963701]Give me the DC voltage on all 16 pins of the TL494. Place the black meter probe on chassis ground. Place the red meter probe on the point where you need to measure the voltage.


Pin 1: 0.0
Pin 2: 0.0
Pin 3: .25
Pin 4: 13.0
Pin 5: 5.0
Pin 6: 5.0
Pin 7: 5.0
Pin 8: 0
Pin 9: .25
Pin 10: 0
Pin 11: 13.7
Pin 12: 1.5
Pin 13: .25
Pin 14: .68
Pin 15: 5.0
Pin 16: .6

Now I put the black meter on the ground termina, the terminal on the amp labled ground was not giving me anything. But later found a different ground terminal that worked fine.

[Perry Babin]

Are you saying that placing the black probe on the large ground terminal of the amp didn't produce any voltage readings?

The voltages aren't correct. I think I know what they are except for 11 which may have been 3.7 (actually pin 6). Look at the following drawing and re-post the numbers.
http://www.bcae1.com/temp/tl494pinconfiguration01.jpg

[rolexcomm]

I think I might have did the pins backwards. I couldn't figure out number 1.

[rolexcomm]

No, I used a ground terminal on the board that didn't have voltage, but i did use the large terminal. Then I found another ground terminal on the board that was ok and checked out. You say chasis ground and I am a car man so that tells me to look for something other than the supply side or hookups. Anyways, the tl494 does not have a dimple on it. and yes the 11 is 3.7 sorry bout the mixup.

[Perry Babin]

Chassis ground terminal = terminal you connect to the chassis of the vehicle.

Give me the DC voltage on the 5 pins of the vertical board. Left to right, looking at component side of the board.


Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:

[rolexcomm]

[QUOTE=Perry Babin;1963756]Chassis ground terminal = terminal you connect to the chassis of the vehicle.

Give me the DC voltage on the 5 pins of the vertical board. Left to right, looking at component side of the board.


Pin 1: 13.66
Pin 2: 0
Pin 3: 5.0
Pin 4: 257.2mv
Pin 5: 13.9

[Perry Babin]

That's not what it should be. I'll have to get back in the shop to check something before I can tell you what to do next.

[rolexcomm]

Originally Posted by Perry Babin

That's not what it should be. I'll have to get back in the shop to check something before I can tell you what to do next.

Have you had a chance to check this out?

[Perry Babin]

Give me the DC voltage on all 14 pins of the LM339. Place the black meter probe on chassis ground. Place the red meter probe on the point where you need to measure the voltage. Be careful. Don't allow your probe to slip and short between the pins of the IC. If the probes aren't sharp, sharpen them. Have the transistors clamped and either a 10 amp fuse or a 2 ohm current limiting resistor in series with the B+ line.

LM339
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14: