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-   -   Yaesu FRG-7700 display ??? (https://www.radiobanter.com/equipment/20678-yaesu-frg-7700-display.html)

Mark S. Holden January 3rd 05 10:19 PM

dxAce wrote:

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'?


I think his problem is a 0 looks the same as an 8 and a 7 looks like a
backwards F - the middle horizontal bar is lit all the time.


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




dxAce January 3rd 05 10:22 PM



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




dxAce January 3rd 05 10:22 PM



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




Brian Hill January 3rd 05 11:26 PM


"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.



Brian Hill January 3rd 05 11:26 PM


"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.



James Sweet January 4th 05 02:57 AM


"Henry Kolesnik" wrote in message
m...
All the center segments stay bright, no blinking.
tnx



If I understand you right, it sounds like you have a shorted transistor
driving either the rows or columns of the multiplexed display.



James Sweet January 4th 05 02:57 AM


"Henry Kolesnik" wrote in message
m...
All the center segments stay bright, no blinking.
tnx



If I understand you right, it sounds like you have a shorted transistor
driving either the rows or columns of the multiplexed display.



eddumweer January 4th 05 09:57 AM

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 January 4th 05 05:02 PM

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









Mark S. Holden January 4th 05 05:26 PM

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








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