Hi,
Have a trigger problem with a 2213 tektronix.

In auto and line trigger i have a baseline. In norm not. Also ext. trigger fails (signal from function generator 4v pp and ch1 on 1v/div)

cannot get still image to see frequency, amplitude is ok. with signal on one of the channels, trig in auto i can almost get still image if freq is low enough with var hold-off. trig-level does nothing. Also the trigger led never blinks.

Checked all p.s. voltages. Are ok (no ripples), but according to service manual there should be some specific resistance on the voltages. These are way too low in my scope:
8.6v 114 ohm at tp500= 58 ohm
+8.6v 95 ohm at W975 = 16 ohm
+5v 330 ohm at W985 = 16 ohm
+30v 905 ohm at W965 = 16 ohm
+100v 12.5 kohm at W966 = 16 ohm

so i guess something is wrong somewhere. checked the big capacitors in the p.s, for 30V and +8.6V, both were in spec.

Are these resistance values in the manual a good reference for finding the faulty area?

regards, tjeenz

I would start by looking at TP444 (middle of schematic 4) which should
be a duplicate of the trigger input signal as selected by the source
and coupling controls. At the very least, there should be a 60Hz sine
wave at that point when the trigger source is set to line.

Then I would check pin 2 of U460B which should be a duplicate of the
tri.gger level voltage as set by the trigger level control. In Auto
mode this voltage will be between the peak levels of the trigger
signal but in normal mode, it should be between +0.65V and -0.65V.

It would be nice to have a nicer scan of the service manual. I
extracted and cleaned up schematic 4 from the one available online:



On Tue, 18 Sep 2012 11:00:41 -0000, "tjeenz" <tjeenz@...> wrote:

Hi,
Have a trigger problem with a 2213 tektronix.

In auto and line trigger i have a baseline. In norm not. Also ext. trigger fails (signal from function generator 4v pp and ch1 on 1v/div)

cannot get still image to see frequency, amplitude is ok. with signal on one of the channels, trig in auto i can almost get still image if freq is low enough with var hold-off. trig-level does nothing. Also the trigger led never blinks.

Checked all p.s. voltages. Are ok (no ripples), but according to service manual there should be some specific resistance on the voltages. These are way too low in my scope:
8.6v 114 ohm at tp500= 58 ohm
+8.6v 95 ohm at W975 = 16 ohm
+5v 330 ohm at W985 = 16 ohm
+30v 905 ohm at W965 = 16 ohm
+100v 12.5 kohm at W966 = 16 ohm

so i guess something is wrong somewhere. checked the big capacitors in the p.s, for 30V and +8.6V, both were in spec.

Are these resistance values in the manual a good reference for finding the faulty area?

regards, tjeenz

hi David,
thx for the tip! i will check this as soon as possible (couple days out of town). i check tp444 before with ext. trigger and that was very small compared to the input signal. don't know the exact amplitude but much lower.
probably back on saturday. tjeenz.

--- In TekScopes@..., David <davidwhess@> wrote:

I would start by looking at TP444 (middle of schematic 4) which should
be a duplicate of the trigger input signal as selected by the source
and coupling controls. At the very least, there should be a 60Hz sine
wave at that point when the trigger source is set to line.

Then I would check pin 2 of U460B which should be a duplicate of the
tri.gger level voltage as set by the trigger level control. In Auto
mode this voltage will be between the peak levels of the trigger
signal but in normal mode, it should be between +0.65V and -0.65V.

It would be nice to have a nicer scan of the service manual. I
extracted and cleaned up schematic 4 from the one available online:



On Tue, 18 Sep 2012 11:00:41 -0000, "tjeenz" <tjeenz@> wrote:

Hi,
Have a trigger problem with a 2213 tektronix.

In auto and line trigger i have a baseline. In norm not. Also ext. trigger fails (signal from function generator 4v pp and ch1 on 1v/div)

cannot get still image to see frequency, amplitude is ok. with signal on one of the channels, trig in auto i can almost get still image if freq is low enough with var hold-off. trig-level does nothing. Also the trigger led never blinks.

Checked all p.s. voltages. Are ok (no ripples), but according to service manual there should be some specific resistance on the voltages. These are way too low in my scope:
8.6v 114 ohm at tp500= 58 ohm
+8.6v 95 ohm at W975 = 16 ohm
+5v 330 ohm at W985 = 16 ohm
+30v 905 ohm at W965 = 16 ohm
+100v 12.5 kohm at W966 = 16 ohm

so i guess something is wrong somewhere. checked the big capacitors in the p.s, for 30V and +8.6V, both were in spec.

Are these resistance values in the manual a good reference for finding the faulty area?

regards, tjeenz

Hi David, still out there?

back from trip...
I checked tp444:
with trig on "line" i have a sinus with about 0.5V tt

if i connect a 4V top-top sinus at ch1 with trig on "int" i have 150mV sinus on tp444 (very small)

U460B, pin 2:
norm: there is indeed a +0.65 - -0.65V which can be controlled by the trig-lev. pot.
auto: sinus 50 mV (again with 4V tt at ch1). which seems very small...

in all situations the display does not show a "still" image.

tjeenz


--- In TekScopes@..., "tjeenz" <tjeenz@...> wrote:

hi David,
thx for the tip! i will check this as soon as possible (couple days out of town). i check tp444 before with ext. trigger and that was very small compared to the input signal. don't know the exact amplitude but much lower.
probably back on saturday. tjeenz.

--- In TekScopes@..., David <davidwhess@> wrote:

I would start by looking at TP444 (middle of schematic 4) which should
be a duplicate of the trigger input signal as selected by the source
and coupling controls. At the very least, there should be a 60Hz sine
wave at that point when the trigger source is set to line.

Then I would check pin 2 of U460B which should be a duplicate of the
tri.gger level voltage as set by the trigger level control. In Auto
mode this voltage will be between the peak levels of the trigger
signal but in normal mode, it should be between +0.65V and -0.65V.

It would be nice to have a nicer scan of the service manual. I
extracted and cleaned up schematic 4 from the one available online:



On Tue, 18 Sep 2012 11:00:41 -0000, "tjeenz" <tjeenz@> wrote:

Hi,
Have a trigger problem with a 2213 tektronix.

In auto and line trigger i have a baseline. In norm not. Also ext. trigger fails (signal from function generator 4v pp and ch1 on 1v/div)

cannot get still image to see frequency, amplitude is ok. with signal on one of the channels, trig in auto i can almost get still image if freq is low enough with var hold-off. trig-level does nothing. Also the trigger led never blinks.

Checked all p.s. voltages. Are ok (no ripples), but according to service manual there should be some specific resistance on the voltages. These are way too low in my scope:
8.6v 114 ohm at tp500= 58 ohm
+8.6v 95 ohm at W975 = 16 ohm
+5v 330 ohm at W985 = 16 ohm
+30v 905 ohm at W965 = 16 ohm
+100v 12.5 kohm at W966 = 16 ohm

so i guess something is wrong somewhere. checked the big capacitors in the p.s, for 30V and +8.6V, both were in spec.

Are these resistance values in the manual a good reference for finding the faulty area?

regards, tjeenz

That narrows the problem down to some point at or after transistor
array U460. The good news is that the 2213 does not use a custom
trigger IC so if the problem can be found, it should be relatively
easy to fix.

With the trigger set to LINE and AUTO, adjust the LEVEL to midway and
measure pin 10 of U480C and pin 7 of U480B. With both SLOPE settings,
there should be at least a 300mV to 400mV square wave on each pin.

If there is, then check pin 2 of U480A. It should have a 300mV to
400mV square wave.

On Sun, 23 Sep 2012 10:51:11 -0000, "tjeenz" <tjeenz@...> wrote:

Hi David, still out there?

back from trip...
I checked tp444:
with trig on "line" i have a sinus with about 0.5V tt

if i connect a 4V top-top sinus at ch1 with trig on "int" i have 150mV sinus on tp444 (very small)

U460B, pin 2:
norm: there is indeed a +0.65 - -0.65V which can be controlled by the trig-lev. pot.
auto: sinus 50 mV (again with 4V tt at ch1). which seems very small...

in all situations the display does not show a "still" image.

tjeenz


--- In TekScopes@..., "tjeenz" <tjeenz@> wrote:

hi David,
thx for the tip! i will check this as soon as possible (couple days out of town). i check tp444 before with ext. trigger and that was very small compared to the input signal. don't know the exact amplitude but much lower.
probably back on saturday. tjeenz.

--- In TekScopes@..., David <davidwhess@> wrote:

I would start by looking at TP444 (middle of schematic 4) which should
be a duplicate of the trigger input signal as selected by the source
and coupling controls. At the very least, there should be a 60Hz sine
wave at that point when the trigger source is set to line.

Then I would check pin 2 of U460B which should be a duplicate of the
tri.gger level voltage as set by the trigger level control. In Auto
mode this voltage will be between the peak levels of the trigger
signal but in normal mode, it should be between +0.65V and -0.65V.

It would be nice to have a nicer scan of the service manual. I
extracted and cleaned up schematic 4 from the one available online:



On Tue, 18 Sep 2012 11:00:41 -0000, "tjeenz" <tjeenz@> wrote:

Hi,
Have a trigger problem with a 2213 tektronix.

In auto and line trigger i have a baseline. In norm not. Also ext. trigger fails (signal from function generator 4v pp and ch1 on 1v/div)

cannot get still image to see frequency, amplitude is ok. with signal on one of the channels, trig in auto i can almost get still image if freq is low enough with var hold-off. trig-level does nothing. Also the trigger led never blinks.

Checked all p.s. voltages. Are ok (no ripples), but according to service manual there should be some specific resistance on the voltages. These are way too low in my scope:
8.6v 114 ohm at tp500= 58 ohm
+8.6v 95 ohm at W975 = 16 ohm
+5v 330 ohm at W985 = 16 ohm
+30v 905 ohm at W965 = 16 ohm
+100v 12.5 kohm at W966 = 16 ohm

so i guess something is wrong somewhere. checked the big capacitors in the p.s, for 30V and +8.6V, both were in spec.

Are these resistance values in the manual a good reference for finding the faulty area?

regards, tjeenz

Hi David,

no square wave on the pins 10 and 7, both slopes.... it just measures a +4V dc, at both pins. Does it mean my U460 has died?

T.

--- In TekScopes@..., David <davidwhess@...> wrote:

That narrows the problem down to some point at or after transistor
array U460. The good news is that the 2213 does not use a custom
trigger IC so if the problem can be found, it should be relatively
easy to fix.

With the trigger set to LINE and AUTO, adjust the LEVEL to midway and
measure pin 10 of U480C and pin 7 of U480B. With both SLOPE settings,
there should be at least a 300mV to 400mV square wave on each pin.

If there is, then check pin 2 of U480A. It should have a 300mV to
400mV square wave.

On Sun, 23 Sep 2012 10:51:11 -0000, "tjeenz" <tjeenz@...> wrote:

Hi David, still out there?

back from trip...
I checked tp444:
with trig on "line" i have a sinus with about 0.5V tt

if i connect a 4V top-top sinus at ch1 with trig on "int" i have 150mV sinus on tp444 (very small)

U460B, pin 2:
norm: there is indeed a +0.65 - -0.65V which can be controlled by the trig-lev. pot.
auto: sinus 50 mV (again with 4V tt at ch1). which seems very small...

in all situations the display does not show a "still" image.

tjeenz


--- In TekScopes@..., "tjeenz" <tjeenz@> wrote:

hi David,
thx for the tip! i will check this as soon as possible (couple days out of town). i check tp444 before with ext. trigger and that was very small compared to the input signal. don't know the exact amplitude but much lower.
probably back on saturday. tjeenz.

--- In TekScopes@..., David <davidwhess@> wrote:

I would start by looking at TP444 (middle of schematic 4) which should
be a duplicate of the trigger input signal as selected by the source
and coupling controls. At the very least, there should be a 60Hz sine
wave at that point when the trigger source is set to line.

Then I would check pin 2 of U460B which should be a duplicate of the
tri.gger level voltage as set by the trigger level control. In Auto
mode this voltage will be between the peak levels of the trigger
signal but in normal mode, it should be between +0.65V and -0.65V.

It would be nice to have a nicer scan of the service manual. I
extracted and cleaned up schematic 4 from the one available online:



On Tue, 18 Sep 2012 11:00:41 -0000, "tjeenz" <tjeenz@> wrote:

Hi,
Have a trigger problem with a 2213 tektronix.

In auto and line trigger i have a baseline. In norm not. Also ext. trigger fails (signal from function generator 4v pp and ch1 on 1v/div)

cannot get still image to see frequency, amplitude is ok. with signal on one of the channels, trig in auto i can almost get still image if freq is low enough with var hold-off. trig-level does nothing. Also the trigger led never blinks.

Checked all p.s. voltages. Are ok (no ripples), but according to service manual there should be some specific resistance on the voltages. These are way too low in my scope:
8.6v 114 ohm at tp500= 58 ohm
+8.6v 95 ohm at W975 = 16 ohm
+5v 330 ohm at W985 = 16 ohm
+30v 905 ohm at W965 = 16 ohm
+100v 12.5 kohm at W966 = 16 ohm

so i guess something is wrong somewhere. checked the big capacitors in the p.s, for 30V and +8.6V, both were in spec.

Are these resistance values in the manual a good reference for finding the faulty area?

regards, tjeenz

U460 is not necessarily bad but if it is, the CA3102 transistor array
is not expensive or difficult to acquire. If U480 is bad, the 10102
ECL Quad 2-input NOR gate is readily available.

4 volts at both pin 10 of U480C and pin 7 of U480B is consistent with
a logical high for a 10102 when operated at PECL levels but one pin of
that pair should be low.

Check the voltage at pin 3 or 9 of U460. R456 might be open so check
its resistance.

Check pin 8 or 1 of U460 which should be 2.2 volts.

Check pin 11 or 4 of U460. It should be either 2.4 volts or 2.0 volts
depending on the trigger slope setting.

If U460 is socketted, then you could pull it and check the transistor
junctions with the diode test function on your multimeter.

On Mon, 24 Sep 2012 02:58:59 -0000, "tjeenz" <tjeenz@...> wrote:

Hi David,

no square wave on the pins 10 and 7, both slopes.... it just measures a +4V dc, at both pins. Does it mean my U460 has died?

T.

--- In TekScopes@..., David <davidwhess@> wrote:

That narrows the problem down to some point at or after transistor
array U460. The good news is that the 2213 does not use a custom
trigger IC so if the problem can be found, it should be relatively
easy to fix.

With the trigger set to LINE and AUTO, adjust the LEVEL to midway and
measure pin 10 of U480C and pin 7 of U480B. With both SLOPE settings,
there should be at least a 300mV to 400mV square wave on each pin.

If there is, then check pin 2 of U480A. It should have a 300mV to
400mV square wave.

On Sun, 23 Sep 2012 10:51:11 -0000, "tjeenz" <tjeenz@> wrote:

Hi David, still out there?

back from trip...
I checked tp444:
with trig on "line" i have a sinus with about 0.5V tt

if i connect a 4V top-top sinus at ch1 with trig on "int" i have 150mV sinus on tp444 (very small)

U460B, pin 2:
norm: there is indeed a +0.65 - -0.65V which can be controlled by the trig-lev. pot.
auto: sinus 50 mV (again with 4V tt at ch1). which seems very small...

in all situations the display does not show a "still" image.

tjeenz


--- In TekScopes@..., "tjeenz" <tjeenz@> wrote:

hi David,
thx for the tip! i will check this as soon as possible (couple days out of town). i check tp444 before with ext. trigger and that was very small compared to the input signal. don't know the exact amplitude but much lower.
probably back on saturday. tjeenz.

--- In TekScopes@..., David <davidwhess@> wrote:

I would start by looking at TP444 (middle of schematic 4) which should
be a duplicate of the trigger input signal as selected by the source
and coupling controls. At the very least, there should be a 60Hz sine
wave at that point when the trigger source is set to line.

Then I would check pin 2 of U460B which should be a duplicate of the
tri.gger level voltage as set by the trigger level control. In Auto
mode this voltage will be between the peak levels of the trigger
signal but in normal mode, it should be between +0.65V and -0.65V.

It would be nice to have a nicer scan of the service manual. I
extracted and cleaned up schematic 4 from the one available online:



On Tue, 18 Sep 2012 11:00:41 -0000, "tjeenz" <tjeenz@> wrote:

Hi,
Have a trigger problem with a 2213 tektronix.

In auto and line trigger i have a baseline. In norm not. Also ext. trigger fails (signal from function generator 4v pp and ch1 on 1v/div)

cannot get still image to see frequency, amplitude is ok. with signal on one of the channels, trig in auto i can almost get still image if freq is low enough with var hold-off. trig-level does nothing. Also the trigger led never blinks.

Checked all p.s. voltages. Are ok (no ripples), but according to service manual there should be some specific resistance on the voltages. These are way too low in my scope:
8.6v 114 ohm at tp500= 58 ohm
+8.6v 95 ohm at W975 = 16 ohm
+5v 330 ohm at W985 = 16 ohm
+30v 905 ohm at W965 = 16 ohm
+100v 12.5 kohm at W966 = 16 ohm

so i guess something is wrong somewhere. checked the big capacitors in the p.s, for 30V and +8.6V, both were in spec.

Are these resistance values in the manual a good reference for finding the faulty area?

regards, tjeenz

Hi,
Voltage U460 pin3 and 9 is -8.6V, R456 is ok.
pin 1 and 8 are 3.5V not 2.2
pin 4 and 11 check out ok, 2 and 2.4V dependent on the slope setting.

u460 is unfortunately not on a socket.

To access u460 and area, i see i have to remove some components. I will start on that a.s.a.p. but a question: some loose contact in the timebase switch. sometimes it generates only half screen image when i move with that knob. is that the pot-meter in the middle?

T.



--- In TekScopes@..., David <davidwhess@> wrote:

U460 is not necessarily bad but if it is, the CA3102 transistor array
is not expensive or difficult to acquire. If U480 is bad, the 10102
ECL Quad 2-input NOR gate is readily available.

4 volts at both pin 10 of U480C and pin 7 of U480B is consistent with
a logical high for a 10102 when operated at PECL levels but one pin of
that pair should be low.

Check the voltage at pin 3 or 9 of U460. R456 might be open so check
its resistance.

Check pin 8 or 1 of U460 which should be 2.2 volts.

Check pin 11 or 4 of U460. It should be either 2.4 volts or 2.0 volts
depending on the trigger slope setting.

If U460 is socketted, then you could pull it and check the transistor
junctions with the diode test function on your multimeter.

On Mon, 24 Sep 2012 02:58:59 -0000, "tjeenz" <tjeenz@> wrote:

Hi David,

no square wave on the pins 10 and 7, both slopes.... it just measures a +4V dc, at both pins. Does it mean my U460 has died?

T.

--- In TekScopes@..., David <davidwhess@> wrote:

That narrows the problem down to some point at or after transistor
array U460. The good news is that the 2213 does not use a custom
trigger IC so if the problem can be found, it should be relatively
easy to fix.

With the trigger set to LINE and AUTO, adjust the LEVEL to midway and
measure pin 10 of U480C and pin 7 of U480B. With both SLOPE settings,
there should be at least a 300mV to 400mV square wave on each pin.

If there is, then check pin 2 of U480A. It should have a 300mV to
400mV square wave.

On Sun, 23 Sep 2012 10:51:11 -0000, "tjeenz" <tjeenz@> wrote:

Hi David, still out there?

back from trip...
I checked tp444:
with trig on "line" i have a sinus with about 0.5V tt

if i connect a 4V top-top sinus at ch1 with trig on "int" i have 150mV sinus on tp444 (very small)

U460B, pin 2:
norm: there is indeed a +0.65 - -0.65V which can be controlled by the trig-lev. pot.
auto: sinus 50 mV (again with 4V tt at ch1). which seems very small...

in all situations the display does not show a "still" image.

tjeenz


--- In TekScopes@..., "tjeenz" <tjeenz@> wrote:

hi David,
thx for the tip! i will check this as soon as possible (couple days out of town). i check tp444 before with ext. trigger and that was very small compared to the input signal. don't know the exact amplitude but much lower.
probably back on saturday. tjeenz.

--- In TekScopes@..., David <davidwhess@> wrote:

I would start by looking at TP444 (middle of schematic 4) which should
be a duplicate of the trigger input signal as selected by the source
and coupling controls. At the very least, there should be a 60Hz sine
wave at that point when the trigger source is set to line.

Then I would check pin 2 of U460B which should be a duplicate of the
tri.gger level voltage as set by the trigger level control. In Auto
mode this voltage will be between the peak levels of the trigger
signal but in normal mode, it should be between +0.65V and -0.65V.

It would be nice to have a nicer scan of the service manual. I
extracted and cleaned up schematic 4 from the one available online:



On Tue, 18 Sep 2012 11:00:41 -0000, "tjeenz" <tjeenz@> wrote:

Hi,
Have a trigger problem with a 2213 tektronix.

In auto and line trigger i have a baseline. In norm not. Also ext. trigger fails (signal from function generator 4v pp and ch1 on 1v/div)

cannot get still image to see frequency, amplitude is ok. with signal on one of the channels, trig in auto i can almost get still image if freq is low enough with var hold-off. trig-level does nothing. Also the trigger led never blinks.

Checked all p.s. voltages. Are ok (no ripples), but according to service manual there should be some specific resistance on the voltages. These are way too low in my scope:
8.6v 114 ohm at tp500= 58 ohm
+8.6v 95 ohm at W975 = 16 ohm
+5v 330 ohm at W985 = 16 ohm
+30v 905 ohm at W965 = 16 ohm
+100v 12.5 kohm at W966 = 16 ohm

so i guess something is wrong somewhere. checked the big capacitors in the p.s, for 30V and +8.6V, both were in spec.

Are these resistance values in the manual a good reference for finding the faulty area?

regards, tjeenz

On Mon, 24 Sep 2012 10:43:12 -0000, "tjeenz" <tjeenz@...> wrote:

I removed u460. (ca3102 from rca). it is broken (20ohm between 1 and 14 in both directions)
also i found a diode connected on the top to pin 12. i couldn't detect pin 12 in the schematics... now start looking for a ca3102

On Mon, 24 Sep 2012 08:50:17 -0000, "tjeenz" <tjeenz@...> wrote:

Voltage U460 pin3 and 9 is -8.6V, R456 is ok.
pin 1 and 8 are 3.5V not 2.2

That fits with pin 1 being 3.5 volts instead of 2.2 volts. The low
resistance between the collector and base is pulling that node up via
the high output of U480C.

Pin 2 and pin 10 at about 0.0 volts while pin 3 is -8.6 volts suggests
that the emitters of U460E and U460B is open as well.

Pin 12 and pin 5 are connected internally to the substrate. The
CA3102 is built on a junction isolated process so the substrate
connects to each transistor via a diode which is reverse biased to
provide isolation.

u460 is unfortunately not on a socket.

When replacing U460, I would cut the collet pins out of an IC socket
and individually install them into the PC board to make a low profile
socket for the new IC.

To access u460 and area, i see i have to remove some components. I will start on that a.s.a.p. but a question: some loose contact in the timebase switch. sometimes it generates only half screen image when i move with that knob. is that the pot-meter in the middle?

From what I remember of the 2213, the timebase switch uses a different
and unreliable design from the other 22xx series oscilloscopes.
Someone else may have suggestions for repairing it.

On Mon, 24 Sep 2012 10:43:12 -0000, "tjeenz" <tjeenz@...> wrote:

I removed u460. (ca3102 from rca). it is broken (20ohm between 1 and 14 in both directions)
also i found a diode connected on the top to pin 12. i couldn't detect pin 12 in the schematics... now start looking for a ca3102

On Mon, 24 Sep 2012 08:50:17 -0000, "tjeenz" <tjeenz@...> wrote:

Voltage U460 pin3 and 9 is -8.6V, R456 is ok.
pin 1 and 8 are 3.5V not 2.2

That fits with pin 1 being 3.5 volts instead of 2.2 volts. The low
resistance between the collector and base is pulling that node up via
the high output of U480C.

Pin 2 and pin 10 at about 0.0 volts while pin 3 is -8.6 volts suggests
that the emitters of U460E and U460B is open as well.

Pin 12 and pin 5 are connected internally to the substrate. The
CA3102 is built on a junction isolated process so the substrate
connects to each transistor via a diode which is reverse biased to
provide isolation.

u460 is unfortunately not on a socket.

When replacing U460, I would cut the collet pins out of an IC socket
and individually install them into the PC board to make a low profile
socket for the new IC.

To access u460 and area, i see i have to remove some components. I will start on that a.s.a.p. but a question: some loose contact in the timebase switch. sometimes it generates only half screen image when i move with that knob. is that the pot-meter in the middle?

From what I remember of the 2213, the timebase switch uses a different
and unreliable design from the other 22xx series oscilloscopes.
Someone else may have suggestions for repairing it.

----- Original Message -----

From: tjeenz

To: TekScopes@...

Sent: Saturday, September 29, 2012 2:34 AM

Subject: [TekScopes] Re: 2213 no trigger

?

Hi David,

After waiting for one week for the ca3102, I found out it is not available here (thailand, bangkok area). I checked the internet but come out at companies who want to have minimum order of 150usd.
amazon lists them for 8 usd and shipping around 20 usd. maybe you know of a cheaper seller/location?

tjeenz.

--- In TekScopes@..., David wrote:
>
> On Mon, 24 Sep 2012 10:43:12 -0000, "tjeenz" wrote:
>
> >I removed u460. (ca3102 from rca). it is broken (20ohm between 1 and 14 in both directions)
> >also i found a diode connected on the top to pin 12. i couldn't detect pin 12 in the schematics... now start looking for a ca3102
>
> On Mon, 24 Sep 2012 08:50:17 -0000, "tjeenz" wrote:
>
> >> Voltage U460 pin3 and 9 is -8.6V, R456 is ok.
> >> pin 1 and 8 are 3.5V not 2.2
>
> That fits with pin 1 being 3.5 volts instead of 2.2 volts. The low
> resistance between the collector and base is pulling that node up via
> the high output of U480C.
>
> Pin 2 and pin 10 at about 0.0 volts while pin 3 is -8.6 volts suggests
> that the emitters of U460E and U460B is open as well.
>
> Pin 12 and pin 5 are connected internally to the substrate. The
> CA3102 is built on a junction isolated process so the substrate
> connects to each transistor via a diode which is reverse biased to
> provide isolation.
>
> >> u460 is unfortunately not on a socket.
>
> When replacing U460, I would cut the collet pins out of an IC socket
> and individually install them into the PC board to make a low profile
> socket for the new IC.
>
>
>
> >> To access u460 and area, i see i have to remove some components. I will start on that a.s.a.p. but a question: some loose contact in the timebase switch. sometimes it generates only half screen image when i move with that knob. is that the pot-meter in the middle?
>
> From what I remember of the 2213, the timebase switch uses a different
> and unreliable design from the other 22xx series oscilloscopes.
> Someone else may have suggestions for repairing it.
>

There are two Chinese sellers on eBay who say they have the CA3102.
Another thought... the 2213A, 2215A, 2235, etc. all have three of those CA3102 chips on the mainboard.
Is there any chance of someone in your part of the world having a broken 22xx with some CA3102?
The part is not worth much, but the shipping to Thailand costs a lot.
tom jobe...



----- Original Message -----
From: tjeenz
To: TekScopes@...
Sent: Saturday, September 29, 2012 2:34 AM
Subject: [TekScopes] Re: 2213 no trigger



Hi David,

After waiting for one week for the ca3102, I found out it is not available here (thailand, bangkok area). I checked the internet but come out at companies who want to have minimum order of 150usd.
amazon lists them for 8 usd and shipping around 20 usd. maybe you know of a cheaper seller/location?

tjeenz.

--- In TekScopes@..., David <davidwhess@> wrote:
>
> On Mon, 24 Sep 2012 10:43:12 -0000, "tjeenz" <tjeenz@> wrote:
>
> >I removed u460. (ca3102 from rca). it is broken (20ohm between 1 and 14 in both directions)
> >also i found a diode connected on the top to pin 12. i couldn't detect pin 12 in the schematics... now start looking for a ca3102
>
> On Mon, 24 Sep 2012 08:50:17 -0000, "tjeenz" <tjeenz@> wrote:
>
> >> Voltage U460 pin3 and 9 is -8.6V, R456 is ok.
> >> pin 1 and 8 are 3.5V not 2.2
>
> That fits with pin 1 being 3.5 volts instead of 2.2 volts. The low
> resistance between the collector and base is pulling that node up via
> the high output of U480C.
>
> Pin 2 and pin 10 at about 0.0 volts while pin 3 is -8.6 volts suggests
> that the emitters of U460E and U460B is open as well.
>
> Pin 12 and pin 5 are connected internally to the substrate. The
> CA3102 is built on a junction isolated process so the substrate
> connects to each transistor via a diode which is reverse biased to
> provide isolation.
>
> >> u460 is unfortunately not on a socket.
>
> When replacing U460, I would cut the collet pins out of an IC socket
> and individually install them into the PC board to make a low profile
> socket for the new IC.
>
>
>
> >> To access u460 and area, i see i have to remove some components. I will start on that a.s.a.p. but a question: some loose contact in the timebase switch. sometimes it generates only half screen image when i move with that knob. is that the pot-meter in the middle?
>
> From what I remember of the 2213, the timebase switch uses a different
> and unreliable design from the other 22xx series oscilloscopes.
> Someone else may have suggestions for repairing it.
>