hello guys,
i'm new here, not afford in repair caramp but i have already repaired many weird thigs : phones, tv,.... bga and microsoldering too
but carmap is a new world, already repaired some but i don't understand this issue with a rockford 1501 old stuff.
when powered, red led is ok, not protect mode but i have no output sound . and the board does a acute noise, continuously.
the fets are all goods, no short , no excessive heat
i test voltages on sg3526 and that's not good but don't understand where i have to start checking more, this is the voltages :
1/ 5
2/ 0.5
3/ 4.2
4/ 4.7
5/ 4.99
6/ 0
7/ 0
8/ 0
9/ 3.6
10/ 2.1
11/ 0
12/ 5
13/ 0
14/ 7.5
15/ 0
16/ 0
17/ 7.5
18/ 5
so i have not enough current on VCC ? no out A and B, no SD and no -E
can you help me please ?
thank you
i'm new here, not afford in repair caramp but i have already repaired many weird thigs : phones, tv,.... bga and microsoldering too
but carmap is a new world, already repaired some but i don't understand this issue with a rockford 1501 old stuff.
when powered, red led is ok, not protect mode but i have no output sound . and the board does a acute noise, continuously.
the fets are all goods, no short , no excessive heat
i test voltages on sg3526 and that's not good but don't understand where i have to start checking more, this is the voltages :
1/ 5
2/ 0.5
3/ 4.2
4/ 4.7
5/ 4.99
6/ 0
7/ 0
8/ 0
9/ 3.6
10/ 2.1
11/ 0
12/ 5
13/ 0
14/ 7.5
15/ 0
16/ 0
17/ 7.5
18/ 5
so i have not enough current on VCC ? no out A and B, no SD and no -E
can you help me please ?
thank you
With the black probe on the ground terminal, what's the DC voltage on the B+ and remote terminals?
hi
mea culpa, i have not onject enought voltage at B+ you right.
so with the right current (12V 2amp) : got these voltages , think it's good :
1/ 5
2/ 3.3
3/ 4.2
4/ 4.7
5/ 4.99
6/ 0
7/ 0
8/ 4,4
9/ 3.6
10/ 2.1
11/ 0
12/ 5
13/ 5,6
14/ 13,4
15/ 0
16/ 5,7
17/ 13,4
18/ 5
the power supply give 2amp .
at this point mesures ont fets are :
fets on the TC1 to TC18 line : left pin : -9V, center pin : 130V !!!, right pin : 0V
fets on the other side TC19 and upper : left pin : 60V, center pin 123V and right pin : 60V
not used to caramp but 130V seems impresssive no ?
mea culpa, i have not onject enought voltage at B+ you right.
so with the right current (12V 2amp) : got these voltages , think it's good :
1/ 5
2/ 3.3
3/ 4.2
4/ 4.7
5/ 4.99
6/ 0
7/ 0
8/ 4,4
9/ 3.6
10/ 2.1
11/ 0
12/ 5
13/ 5,6
14/ 13,4
15/ 0
16/ 5,7
17/ 13,4
18/ 5
the power supply give 2amp .
at this point mesures ont fets are :
fets on the TC1 to TC18 line : left pin : -9V, center pin : 130V !!!, right pin : 0V
fets on the other side TC19 and upper : left pin : 60V, center pin 123V and right pin : 60V
not used to caramp but 130V seems impresssive no ?
You need to use the circuit board designations on the board, not the MEHSA insulator.
To measure the rail voltage, you have to measure directly across the red and black twisted wires.
To measure the rail voltage, you have to measure directly across the red and black twisted wires.
ok, thanks, this caramp are very different than tv or other to repair. need to learn
so the big twister wires are at 123V red probe on red wire, black probe on black wire. stable.
so the big twister wires are at 123V red probe on red wire, black probe on black wire. stable.
Conform that terminals 1 and 7 of U21 are low.
What is the DC voltage on terminal 1 of the LM339?
What is the DC voltage on terminal 1 of the LM339?
here are voltages on lm339
1/ 4
2/ 4.4
3/ 11.7
4/ 0
5/ 1.7
6/ 0
7/ 5
8/ 1.6
9/ 1.6
10/ 5
11/ 6.5
12/ 0
13/ 4.4
14/ 0
thank you
1/ 4
2/ 4.4
3/ 11.7
4/ 0
5/ 1.7
6/ 0
7/ 5
8/ 1.6
9/ 1.6
10/ 5
11/ 6.5
12/ 0
13/ 4.4
14/ 0
thank you
Re-check the voltage on pin 17 of the SG3526 and the voltage on pin 2 of the LM339.
Are they still the same as the posted numbers?
Are they still the same as the posted numbers?
My mistake. I meant pin 3 of the 339 and pin 17 of the 3526.
They should be about the same. Being that far off seemed to indicate that the power supply wasn't running when you measured the voltage on the 339.
They should be about the same. Being that far off seemed to indicate that the power supply wasn't running when you measured the voltage on the 339.
Do you now see my problem? How can you get different readings from two points that are directly connected.
The voltage was different because the conditions in the amp were different.
I need consistency/accuracy with the readings that you give.
Power the amp up and measure the DC voltage on those two pins again. If they are essentially identical, repost the DC voltage for both ICs.
The voltage was different because the conditions in the amp were different.
I need consistency/accuracy with the readings that you give.
Power the amp up and measure the DC voltage on those two pins again. If they are essentially identical, repost the DC voltage for both ICs.
hello
so Pin3 and Pin17 are exactly the same in fact, 12.8V
if i mesure voltages on fets and rectifier can it help you ?
so Pin3 and Pin17 are exactly the same in fact, 12.8V
if i mesure voltages on fets and rectifier can it help you ?
The list of voltages that you posted were of no use because the voltage on 339-3 and 3526-17 were not the same. Repost the list of voltages on both ICs. Check the 3/17 voltage before and after measuring the voltage to confirm that 3 and 17 are very nearly identical the entire time that you're measuring the voltage.
Please (and this applies to anyone who needs repair help) use your sig line to list all equipment you have, editing it as equipment changes. Include the model numbers.
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Oscilloscope (yes or no)
Multimeter(s)
Type of signal source (grounded RCA shields preferred).
Soldering iron
Desoldering pump
Power supply
2 ohm current limiting resistor (hollow cylindrical ceramic 100w preferred)
Please (and this applies to anyone who needs repair help) use your sig line to list all equipment you have, editing it as equipment changes. Include the model numbers.
Top of page, menu USER CP >> EDIT SIGNATURE
Oscilloscope (yes or no)
Multimeter(s)
Type of signal source (grounded RCA shields preferred).
Soldering iron
Desoldering pump
Power supply
2 ohm current limiting resistor (hollow cylindrical ceramic 100w preferred)
hello, sorry but i haven't got the time to do some tests.
so i put 12,2v with external power supply, 2amps
no audio input to do the tests
sg chip :
1/ 5
2/ 3.1
3/ 4.4
4/ 4.7
5/ 4.99
6/ 0
7/ 0
8/ 4.4
9/ 3.6
10/ 2
11/ 0
12/ 4.7
13/ 5.3
14/ 13
15/ 0
16/ 5.4
17/ 12.95
18/ 5
on lm339 got :
1/ 4.4
2/ 4.4
3/ 13.3
4/ 0
5/ 1.7
6/ 3.4
7/ 5
8/ 1.07
9/1.07
10/ 5
11/ 6.5
12/ 0
13/ 4.4
14/ 0
take first on sg then on lm339 at the same sequence of test.
but maybe i find something, on testing u7 and U8 (don't know what this guys does but there are both lm6171 )
u8 : -in 6.4V , +in 0v, v- -9.6v, v+ 9.7V, output _8V (maybe ok no ?)
u7 : -in 0V, +in 0V, v- -9.6V, v+ 9.7V, output 1V
so test u17 : output at -1V, _in and +in at 0V. V- at -9,6 and v+ 9.7v
maybe it can help.
don't know if output of u17 and U7 are normal here
thank you
so i put 12,2v with external power supply, 2amps
no audio input to do the tests
sg chip :
1/ 5
2/ 3.1
3/ 4.4
4/ 4.7
5/ 4.99
6/ 0
7/ 0
8/ 4.4
9/ 3.6
10/ 2
11/ 0
12/ 4.7
13/ 5.3
14/ 13
15/ 0
16/ 5.4
17/ 12.95
18/ 5
on lm339 got :
1/ 4.4
2/ 4.4
3/ 13.3
4/ 0
5/ 1.7
6/ 3.4
7/ 5
8/ 1.07
9/1.07
10/ 5
11/ 6.5
12/ 0
13/ 4.4
14/ 0
take first on sg then on lm339 at the same sequence of test.
but maybe i find something, on testing u7 and U8 (don't know what this guys does but there are both lm6171 )
u8 : -in 6.4V , +in 0v, v- -9.6v, v+ 9.7V, output _8V (maybe ok no ?)
u7 : -in 0V, +in 0V, v- -9.6V, v+ 9.7V, output 1V
so test u17 : output at -1V, _in and +in at 0V. V- at -9,6 and v+ 9.7v
maybe it can help.
don't know if output of u17 and U7 are normal here
thank you
Please (and this applies to anyone who needs repair help) use your sig line to list all equipment you have, editing it as equipment changes. Include the model numbers.
Top of page, menu USER CP >> EDIT SIGNATURE
Oscilloscope (yes or no)
Multimeter(s)
Type of signal source (grounded RCA shields preferred).
Soldering iron
Desoldering pump
Power supply
2 ohm current limiting resistor (hollow cylindrical ceramic 100w preferred)
Top of page, menu USER CP >> EDIT SIGNATURE
Oscilloscope (yes or no)
Multimeter(s)
Type of signal source (grounded RCA shields preferred).
Soldering iron
Desoldering pump
Power supply
2 ohm current limiting resistor (hollow cylindrical ceramic 100w preferred)