Re my previous post - and helpful answers.
[CTC 169 OnScreen Display Problem ]

Chassis is CTC 169AJ
Problem is most likely Horizontal Sync Buffer transistor - Q4402, listed
in the manual as "Stock Number 215495"

Anyone know how to find specs on this, what to replace it with, or where
to get an exact replacement?

TIA - Matt Baum

Order from www.tritronicsinc.com


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Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)

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"Matt Baum" wrote in message
...
Re my previous post - and helpful answers.
[CTC 169 OnScreen Display Problem ]

Chassis is CTC 169AJ
Problem is most likely Horizontal Sync Buffer transistor - Q4402, listed
in the manual as "Stock Number 215495"

Anyone know how to find specs on this, what to replace it with, or where
to get an exact replacement?

TIA - Matt Baum

You are aware this is a surface mount miniture transistor mounted on the bottom
of the board? It's a standard NPN surface mount transistor, comes 5 in a pack
available from any RCA distributer. It takes a small iron and steady hand to
replace.
Ron

Chassis is CTC 169AJ
Problem is most likely Horizontal Sync Buffer transistor - Q4402, listed
in the manual as "Stock Number 215495"

Anyone know how to find specs on this, what to replace it with, or where
to get an exact replacement?

TIA - Matt Baum

Thanks Ron -
Yes, from the manual it is an NPN SMT device.

I primarily want to know if I need anything with high gain; fast speed;
or anything else critical.
It looks like a simple emitter follower - with nothing special going on,
but I would like to be prepared properly with the right new part before
tearing the thing apart.

Any further ideas?

Matt

RonKZ650 wrote:
You are aware this is a surface mount miniture transistor mounted on the bottom
of the board? It's a standard NPN surface mount transistor, comes 5 in a pack
available from any RCA distributer. It takes a small iron and steady hand to
replace.
Ron


Chassis is CTC 169AJ
Problem is most likely Horizontal Sync Buffer transistor - Q4402, listed
in the manual as "Stock Number 215495"

Anyone know how to find specs on this, what to replace it with, or where
to get an exact replacement?

TIA - Matt Baum

This again!

I finally got the transistor & replaced it.
Results same as before - OnScreenDisplay doesn't sync horizontally;
all else seems OK.

Since I now have the set apart, I checked the waveforms.
H pulses OK at base and emitter of Q4402 look just like what the manual
shows. Also waveform right at pin 23 of the micro is OK.

Micro pins 25 &26 (the passive components of the PLL) don't look so
great, but there are no manual waveforms to compare them with.
Any ideas - anybody??