RCA TV CTC169(BG5) Wont come out of standby - Ticking sound

Hi all-

I have an RCA 35" direct view TV. It wont come out of standby.
When the power button is pressed a ticking sound is heard - only while the button is pressed.

Upon inspection, R4001 (1.8 15W) resistor was found to have
cracked solder joints. RT 4201 was replaced because it came apart.
CR4120 was replaced because it was physically blown.

CR4118 was replaced, along with C4102 (2.2@100V)
and C4108 (replaced with 47uf@100V) in an attempt tp fix this problem.

Standby voltage is 143V at TP 4101, and +15 standby is 12.7V at TP4103.
When power button is pressed, both voltages drop (143 down to 110, 127. drops to 10V).

Problem remains - wont come out of standby, ticking sound when power button is pressed.

Appreciate any help

Thanks
Mark

 

[Jason D.]

On Mon, 22 Sep 2003 00:12:25 GMT, <mtreager@dontspammeyahoo.com>
wrote:

Hi all-

I have an RCA 35" direct view TV. It wont come out of standby.
When the power button is pressed a ticking sound is heard - only while the button is pressed.

Upon inspection, R4001 (1.8 15W) resistor was found to have
cracked solder joints. RT 4201 was replaced because it came apart.
CR4120 was replaced because it was physically blown.

This is very clear case that it might had surge or horizontal circuit
blew in turn blew the SMPS.

CR4118 was replaced, along with C4102 (2.2@100V)
and C4108 (replaced with 47uf@100V) in an attempt tp fix this problem.

There are four electrolytic capacitors in SMPS, missed 15uF 100V and
470uF 35V replace them, change 47uF to 39uF 100V this helps the SMPS
to run cooler, was running change during CTC169 production. This cap
is in series from SMPS IC to this base of SMPS Q4101 transistor.

Standby voltage is 143V at TP 4101, and +15 standby is 12.7V at TP4103.
When power button is pressed, both voltages drop (143 down to 110, 127. drops to 10V).

Both volts are good in standby. But you still have a problem in run
mode. Unsolder collector of the HOT (Q4401) and try again. If TV
stays on without ticking, this means either flyback transformer,
focus/G2 screen block or tube is bad.

Carefully decide if this set is worth fixing because most of them I
fixed in 35" size like this tube were usually used up and new tube for
this is over 1,400. New set is best.

The flyback is about $120 retail.

Decide real carefully.

Cheers,

Wizard

 

Thank you Wizard for the help.

I had intended on replacing C4104, but the shop had the wrong part in the kit -
(he had 22uf@16V). I'll get the correct part. I'll also pick up the other cap, C4118 (470uf@35v).

After replacing the 2 caps, I'll try pulling the collector on the HOT.

BTW, What would happen if C4112 or T4101 was fried? I did see a puff of smoke from that area.

I agree with your assessment about fixing it...need a couple more months before the new TV is possible...
.....The set was running fine, just wouldnt turn on the next morning! I'd like to fix it if possible.

Thanks again, Mark

Hi all-

I have an RCA 35" direct view TV. It wont come out of standby.
When the power button is pressed a ticking sound is heard - only while the button is pressed.

Upon inspection, R4001 (1.8 15W) resistor was found to have
cracked solder joints. RT 4201 was replaced because it came apart.
CR4120 was replaced because it was physically blown.

This is very clear case that it might had surge or horizontal circuit
blew in turn blew the SMPS.

CR4118 was replaced, along with C4102 (2.2@100V)
and C4108 (replaced with 47uf@100V) in an attempt tp fix this problem.

There are four electrolytic capacitors in SMPS, missed 15uF 100V and
470uF 35V replace them, change 47uF to 39uF 100V this helps the SMPS
to run cooler, was running change during CTC169 production. This cap
is in series from SMPS IC to this base of SMPS Q4101 transistor.

Standby voltage is 143V at TP 4101, and +15 standby is 12.7V at TP4103.
When power button is pressed, both voltages drop (143 down to 110, 127. drops to 10V).

Both volts are good in standby. But you still have a problem in run
mode. Unsolder collector of the HOT (Q4401) and try again. If TV
stays on without ticking, this means either flyback transformer,
focus/G2 screen block or tube is bad.

Carefully decide if this set is worth fixing because most of them I
fixed in 35" size like this tube were usually used up and new tube for
this is over 1,400. New set is best.

The flyback is about $120 retail.

Decide real carefully.

Cheers,

Wizard

 

[Jason D.]

Thank you Wizard for the help.

Mark,

I had intended on replacing C4104, but the shop had the wrong part in the kit -
(he had 22uf@16V). I'll get the correct part. I'll also pick up the other cap, C4118 (470uf@35v).

After replacing the 2 caps, I'll try pulling the collector on the HOT.

BTW, What would happen if C4112 or T4101 was fried? I did see a puff of smoke from that area.

I'll look at junk chassis and tell you about it tomorrow night.

Cheers,

Wizard

 

An update:

I have replaced 3 of the 4 caps in the SMPS (did not replace the 15uF). Same problem, won't come out of standby.
Voltages drop when power button is pressed, and there is a ticking sound when the power
button is pressed.

I took the collector off of Q4101, and the PS is dead. I took the collector off of Q4101 HOT and SMVS voltages were there (12.7 / 142V).

Looking for the next step. Not ready to scrap the set....yet....

Thanks in advance, wspecially to Wizard.

Mark

Thank you Wizard for the help.

Mark,

I had intended on replacing C4104, but the shop had the wrong part in the kit -
(he had 22uf@16V). I'll get the correct part. I'll also pick up the other cap, C4118 (470uf@35v).

After replacing the 2 caps, I'll try pulling the collector on the HOT.

BTW, What would happen if C4112 or T4101 was fried? I did see a puff of smoke from that area.

I'll look at junk chassis and tell you about it tomorrow night.

Cheers,

Wizard




**********End Of Post*************
On Mon, 22 Sep 2003 00:12:25 GMT, <mtreager@dontspammeyahoo.com>
wrote:

Hi all-

I have an RCA 35" direct view TV. It wont come out of standby.
When the power button is pressed a ticking sound is heard - only while the button is pressed.

Upon inspection, R4001 (1.8 15W) resistor was found to have
cracked solder joints. RT 4201 was replaced because it came apart.
CR4120 was replaced because it was physically blown.

This is very clear case that it might had surge or horizontal circuit
blew in turn blew the SMPS.

CR4118 was replaced, along with C4102 (2.2@100V)
and C4108 (replaced with 47uf@100V) in an attempt tp fix this problem.

There are four electrolytic capacitors in SMPS, missed 15uF 100V and
470uF 35V replace them, change 47uF to 39uF 100V this helps the SMPS
to run cooler, was running change during CTC169 production. This cap
is in series from SMPS IC to this base of SMPS Q4101 transistor.

Standby voltage is 143V at TP 4101, and +15 standby is 12.7V at TP4103.
When power button is pressed, both voltages drop (143 down to 110, 127. drops to 10V).

Both volts are good in standby. But you still have a problem in run
mode. Unsolder collector of the HOT (Q4401) and try again. If TV
stays on without ticking, this means either flyback transformer,
focus/G2 screen block or tube is bad.

Carefully decide if this set is worth fixing because most of them I
fixed in 35" size like this tube were usually used up and new tube for
this is over 1,400. New set is best.

The flyback is about $120 retail.

Decide real carefully.

Cheers,

Wizard


**********End Of Post*************

 

[john]

Does this set have the seperate Screen and Focus block ?

kip

--
"Watch the return E-Mail addy its false"

 

[RonKZ650]

I'd replace the 15uf. Use a 22uf if you don't have the 15 handy. If that
doesn't help, check the horiz drive transistor Q4302. You've already checked
for good 13v standby voltage at CR4118, It's notorious for causing start up
problems.