Henry Kolesnik wrote:

All the center segments stay bright, no blinking.

OK, what is it you wish to blank then? I owned a FRG-7700 for several years.
What exactly do you mean by 'center segments'?


tnx

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

The freqency /time display doesn't blank any of the center segments on
either time or frequency function. Any suggestions on a fix appreciated.
The serial number is 59,800 and I wonder if anyone can tell me if this is
an
early or late model?
tnx

Blank or blink?



--

73
Hank WD5JFR

It's a five digit display made of seven segment digits. The center or "G"
segment doesn't blank when zero is displayed so zero looks like an eight.
It has leading zero suppression and instead of the zero being totally
suppressed the center segment appears as a minus sign.

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

All the center segments stay bright, no blinking.

OK, what is it you wish to blank then? I owned a FRG-7700 for several
years.
What exactly do you mean by 'center segments'?


tnx

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

The freqency /time display doesn't blank any of the center segments on
either time or frequency function. Any suggestions on a fix
appreciated.
The serial number is 59,800 and I wonder if anyone can tell me if this
is
an
early or late model?
tnx

Blank or blink?



--

73
Hank WD5JFR

Henry Kolesnik wrote:

It's a five digit display made of seven segment digits. The center or "G"
segment doesn't blank when zero is displayed so zero looks like an eight.
It has leading zero suppression and instead of the zero being totally
suppressed the center segment appears as a minus sign.

OK, I understand Hank. Sorry, I never encountered that problem. I'm certain
someone will be able to help you out.



--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

All the center segments stay bright, no blinking.

OK, what is it you wish to blank then? I owned a FRG-7700 for several
years.
What exactly do you mean by 'center segments'?


tnx

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

The freqency /time display doesn't blank any of the center segments on
either time or frequency function. Any suggestions on a fix
appreciated.
The serial number is 59,800 and I wonder if anyone can tell me if this
is
an
early or late model?
tnx

Blank or blink?



--

73
Hank WD5JFR

"Henry Kolesnik" wrote in message
m...
It's a five digit display made of seven segment digits. The center or "G"
segment doesn't blank when zero is displayed so zero looks like an eight.
It has leading zero suppression and instead of the zero being totally
suppressed the center segment appears as a minus sign.

--

73
Hank WD5JFR

It sounds like a short in the display board. Did it get dropped? Or maybe a
soda spill?


B.H.

Check the segment transistors position Q1052-Q1056 (2sa733a-q)

One of them will probably be shorted. The signals for the transistors are
coming from ic msm5524 controlling the frequency and time display.

Greetings Peter

"Henry Kolesnik" schreef in bericht
m...
It's a five digit display made of seven segment digits. The center or "G"
segment doesn't blank when zero is displayed so zero looks like an eight.
It has leading zero suppression and instead of the zero being totally
suppressed the center segment appears as a minus sign.

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

All the center segments stay bright, no blinking.

OK, what is it you wish to blank then? I owned a FRG-7700 for several
years.
What exactly do you mean by 'center segments'?


tnx

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

The freqency /time display doesn't blank any of the center segments
on
either time or frequency function. Any suggestions on a fix
appreciated.
The serial number is 59,800 and I wonder if anyone can tell me if
this is
an
early or late model?
tnx

Blank or blink?



--

73
Hank WD5JFR

Peter
Thanks for the tip but I had previously checked the voltages on the
transistors you mention and all are B +4.44, E +4.58 and C -22.4 volts. I
discounted them as being the problem because there's only five and there are
seven segments. My guess is that these transistors are the individual digit
drivers as there are five digits and the segments are muxed from the
msm5524. If I look closely at the copy of a copy many times over of the
schematic I can see where a prevoius owner made notes indicating that the
center segment is driven by pin 25. Any more tips appreciated. As you can
tell I'm out of my league with this kind of stuff.

--

73
Hank WD5JFR
"eddumweer" wrote in message
...
Check the segment transistors position Q1052-Q1056 (2sa733a-q)

One of them will probably be shorted. The signals for the transistors are
coming from ic msm5524 controlling the frequency and time display.

Greetings Peter

"Henry Kolesnik" schreef in bericht
m...
It's a five digit display made of seven segment digits. The center or
"G" segment doesn't blank when zero is displayed so zero looks like an
eight. It has leading zero suppression and instead of the zero being
totally suppressed the center segment appears as a minus sign.

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

All the center segments stay bright, no blinking.

OK, what is it you wish to blank then? I owned a FRG-7700 for several
years.
What exactly do you mean by 'center segments'?


tnx

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

The freqency /time display doesn't blank any of the center segments
on
either time or frequency function. Any suggestions on a fix
appreciated.
The serial number is 59,800 and I wonder if anyone can tell me if
this is
an
early or late model?
tnx

Blank or blink?



--

73
Hank WD5JFR

Henry Kolesnik wrote:

Peter
Thanks for the tip but I had previously checked the voltages on the
transistors you mention and all are B +4.44, E +4.58 and C -22.4 volts. I
discounted them as being the problem because there's only five and there are
seven segments. My guess is that these transistors are the individual digit
drivers as there are five digits and the segments are muxed from the
msm5524. If I look closely at the copy of a copy many times over of the
schematic I can see where a prevoius owner made notes indicating that the
center segment is driven by pin 25. Any more tips appreciated. As you can
tell I'm out of my league with this kind of stuff.


This web page:

http://www.crocuta.com/FRG7700/html/page20.html

indicates the segments are controlled by Q1052 - Q1058 (2SA733A-Q)

So there should be seven transistors there.

If the transistor isn't identified in the schematic, you can narrow down the segment to one of two by tuning to all 1's and then all 2's. 2 segments will have the -25 voltage on them for both tests. You may be able to get a better handle on which of the
two is bad by tuning to 15,555 - the segment that consistently reads the full -25 (or -22.5) is probably the bad one.

I'm not familiar with your radio - just basic trouble shooting.

--

73
Hank WD5JFR
"eddumweer" wrote in message
...
Check the segment transistors position Q1052-Q1056 (2sa733a-q)

One of them will probably be shorted. The signals for the transistors are
coming from ic msm5524 controlling the frequency and time display.

Greetings Peter

"Henry Kolesnik" schreef in bericht
m...
It's a five digit display made of seven segment digits. The center or
"G" segment doesn't blank when zero is displayed so zero looks like an
eight. It has leading zero suppression and instead of the zero being
totally suppressed the center segment appears as a minus sign.

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

All the center segments stay bright, no blinking.

OK, what is it you wish to blank then? I owned a FRG-7700 for several
years.
What exactly do you mean by 'center segments'?


tnx

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

The freqency /time display doesn't blank any of the center segments
on
either time or frequency function. Any suggestions on a fix
appreciated.
The serial number is 59,800 and I wonder if anyone can tell me if
this is
an
early or late model?
tnx

Blank or blink?



--

73
Hank WD5JFR

I fired up the scope and had nice patterns on MSM5524 pins 26 thru 31 about
20 volt PP but pin 25 had about 3volts PP . Later I pulled the chip and
bent pin 25 out and plugged it back and voila, no center segment, anytime.
While the chip was out I checked the pull down resistors and they're all
about 100K ohms. Pin 25 which controls the center segment appears to be the
problem. Now what I need to know is the the IC or could it be something
else?
tnx

--

73
Hank WD5JFR

"Mark S. Holden" wrote in message
...
Henry Kolesnik wrote:

Peter
Thanks for the tip but I had previously checked the voltages on the
transistors you mention and all are B +4.44, E +4.58 and C -22.4 volts.
I
discounted them as being the problem because there's only five and there
are
seven segments. My guess is that these transistors are the individual
digit
drivers as there are five digits and the segments are muxed from the
msm5524. If I look closely at the copy of a copy many times over of the
schematic I can see where a prevoius owner made notes indicating that the
center segment is driven by pin 25. Any more tips appreciated. As you
can
tell I'm out of my league with this kind of stuff.


This web page:

http://www.crocuta.com/FRG7700/html/page20.html

indicates the segments are controlled by Q1052 - Q1058 (2SA733A-Q)

So there should be seven transistors there.

If the transistor isn't identified in the schematic, you can narrow down
the segment to one of two by tuning to all 1's and then all 2's. 2
segments will have the -25 voltage on them for both tests. You may be
able to get a better handle on which of the
two is bad by tuning to 15,555 - the segment that consistently reads the
full -25 (or -22.5) is probably the bad one.

I'm not familiar with your radio - just basic trouble shooting.

--

73
Hank WD5JFR
"eddumweer" wrote in message
...
Check the segment transistors position Q1052-Q1056 (2sa733a-q)

One of them will probably be shorted. The signals for the transistors
are
coming from ic msm5524 controlling the frequency and time display.

Greetings Peter

"Henry Kolesnik" schreef in bericht
m...
It's a five digit display made of seven segment digits. The center or
"G" segment doesn't blank when zero is displayed so zero looks like an
eight. It has leading zero suppression and instead of the zero being
totally suppressed the center segment appears as a minus sign.

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

All the center segments stay bright, no blinking.

OK, what is it you wish to blank then? I owned a FRG-7700 for several
years.
What exactly do you mean by 'center segments'?


tnx

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

The freqency /time display doesn't blank any of the center
segments
on
either time or frequency function. Any suggestions on a fix
appreciated.
The serial number is 59,800 and I wonder if anyone can tell me if
this is
an
early or late model?
tnx

Blank or blink?



--

73
Hank WD5JFR

Henry Kolesnik wrote:
I fired up the scope and had nice patterns on MSM5524 pins 26 thru 31 about
20 volt PP but pin 25 had about 3volts PP . Later I pulled the chip and
bent pin 25 out and plugged it back and voila, no center segment, anytime.
While the chip was out I checked the pull down resistors and they're all
about 100K ohms. Pin 25 which controls the center segment appears to be the
problem. Now what I need to know is the the IC or could it be something
else?
tnx


I presume this is a new acquisition for you.

You've mentioned the previous owner had a note on the schematic
indicating pin 25 controlled that segment.

Sounds to me like he found the problem, and decided it would be easier
to sell with a segment always on than always off.

Murphy's law says since the MSM5524 is out of production and relatively
hard to find it's the most likely problem. (besides, it's the display
driver)

Here's an auction for one I found as part of an unsuccessful search for
a data sheet:

http://search.auctions.shopping.yahoo.com/search?desc=MSM5524+&auccat=23761&st=auct&f=&apg=1 &nm=1&acc=sg&alocale=0sg&sb=desc

You may be able to find a better price.

I only have a bad pdf of it, so that could be the problem.

Indeed check if there are 7 of the same type of transistor there and you can
try it on 2 way's. You can change them one with another or if it is a
leddisplay get the suspected transistor out of it then it must go dark. If
the problem is from pin 25 then check with an oscilloscoop if it's switching
right, looking to another pin with the same function for another segment.

Good luck PP

"Henry Kolesnik" schreef in bericht
m...
Peter
Thanks for the tip but I had previously checked the voltages on the
transistors you mention and all are B +4.44, E +4.58 and C -22.4 volts. I
discounted them as being the problem because there's only five and there
are seven segments. My guess is that these transistors are the individual
digit drivers as there are five digits and the segments are muxed from the
msm5524. If I look closely at the copy of a copy many times over of the
schematic I can see where a prevoius owner made notes indicating that the
center segment is driven by pin 25. Any more tips appreciated. As you
can tell I'm out of my league with this kind of stuff.

--

73
Hank WD5JFR
"eddumweer" wrote in message
...
Check the segment transistors position Q1052-Q1056 (2sa733a-q)

One of them will probably be shorted. The signals for the transistors are
coming from ic msm5524 controlling the frequency and time display.

Greetings Peter

"Henry Kolesnik" schreef in bericht
m...
It's a five digit display made of seven segment digits. The center or
"G" segment doesn't blank when zero is displayed so zero looks like an
eight. It has leading zero suppression and instead of the zero being
totally suppressed the center segment appears as a minus sign.

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

All the center segments stay bright, no blinking.

OK, what is it you wish to blank then? I owned a FRG-7700 for several
years.
What exactly do you mean by 'center segments'?


tnx

--

73
Hank WD5JFR
"dxAce" wrote in message
...


Henry Kolesnik wrote:

The freqency /time display doesn't blank any of the center segments
on
either time or frequency function. Any suggestions on a fix
appreciated.
The serial number is 59,800 and I wonder if anyone can tell me if
this is
an
early or late model?
tnx

Blank or blink?



--

73
Hank WD5JFR