[TechAssist] Re: Projo RCA CTC169 Dead with wrong standby voltages
- From: <damon101@xxxxxxxxxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Sun, 6 Mar 2005 09:09:22 -0500
> > BTW when you push the on button you can see the front led give a slight
> > single blink.
Most common failure for this symptom is the HV Splitter....will cause a
single blink. Disconnect the HV anode wire, TRY to put it in a glass
jar.....I just pull it out, tuck it under the wood slot/holes under the CRTs
and.......most of the time you'll hear it fire up ok.....BUT in the last 6-9
months I've turned it on and I see arcing by the speakers (as tho the wood
has become conductive!!) Thank-you RCA for the light show my customer gets
to see......
But you did mention this too:
> > Regulated B+ is too high I think ...The meter does not like the signal
> > at TP4101 some times 197V sometimes 1.97V??
I have had that......the voltages float up/down/all around......constant or
near constant fluctuation.....sometimes it will kinda pause at one voltage.
Well, that's been the 143V Supply filtering cap that I mentioned beforehand.
The only other part that may cause fluctuation is the 2.2 uf/100V cap C4102,
but that came with the kit and doesn't cause "floating" it just causes the
143V to go up "Most" of the time.
Good luck on this.
Damon Brunger
Telrad Electronics
Fort Wayne IN
----- Original Message -----
From: <damon101@xxxxxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Friday, March 04, 2005 11:30 PM
Subject: [TechAssist] Re: Projo RCA CTC169 Dead with wrong standby voltages
> Not that I know where TP4101 is but.....your B+ should be 143V in standby,
> and 143V in run modes . If you find your meter floating....the B+
> floating...and it is not stable at all, then take a look at the 143V
> supply's main cap. You can 'scope the caps DC and verify it....I've had a
> couple of these with "floating DC" and both had bad cap filtering. The cap
> is located a little behind the 143V rectifier, I think it's 180uf/200V.
>
> Sounds like the kit covered most problems, the C4102 dries out and standby
> 143V rises due to that. The 15uf rarely fails, and is mostly for OCP
> shutdown. The 39uf/47uf situation has never been an issue with any I've
> replaced...If I have a 39....sure I'll use it, but most of the time I have
> 47uf and I have replaced a lot of 39's with it....a few guys will say
> "replace with same as your SMPS output may overheat and die " and that's
> just Bull as the transistor is the same transistor in 39 or 47 circuitry.
>
>
> Damon Brunger
> Telrad Electronics
> Fort Wayne IN
> ----- Original Message -----
> From: "Warren" <warrenca@xxxxxxxxx>
> To: <techassist@xxxxxxxxxxxxx>
> Sent: Friday, March 04, 2005 10:47 PM
> Subject: [TechAssist] Projo RCA CTC169 Dead with wrong standby voltages
>
>
> > Hi all!
> >
> > I will list the work so far:
> >
> > 15 V standby = 14.2
> > 5V standby =4.9V
> > Raw B+=151V
> > Regulated B+ is too high I think ...The meter does not like the signal
> > at TP4101 some times 197V sometimes 1.97V??
> > Should the Reg B+ be 143V before turn on????
> > From cathode of CR4106 to Cathode of CR4101 first I had 2 Volts.... Now
> > after changing diodes I get 3 volts???
> > Should be under 1 Volt.
> >
> > Installed a startup kit from Global Q4101, U4101, C4102, C4118, C4108
> > (47uf) which also was a 47UF before.
> > My schematic shows 39uf ?? does this make a difference??
> > Caps were installed first with Q4101 , IC U4101 was installed
> afterwards.
> > Also changed C4104(15uf) with also no change.
> > I also tried to isolate the H out (curiosity) - no change
> >
> > I've read many tips but most of these point to the parts that I've
> > already changed.
> > Can someone brush up my 169 skills.
> > What am I missing??
> > Does anyone have a troubleshooting flow chart for the 169?? This would
> help.
> >
> > BTW when you push the on button you can see the front led give a slight
> > single blink.
> >
> > TIA all !
> > All tips and comments welcome.
>
> --------------------------------------------------------------------------
> ---
> > This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
> > Lost Password: http://www.tech-assist.org and select "Login Problems?".
> > Email Archives: //www.freelists.org/archives/techassist/
> >
> >
> >
> > --
> > Internal Virus Database is out-of-date.
> > Checked by AVG Anti-Virus.
> > Version: 7.0.298 / Virus Database: 266.4.0 - Release Date: 2/22/2005
> >
> >
>
>
> --------------------------------------------------------------------------
---
> This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
> Lost Password: http://www.tech-assist.org and select "Login Problems?".
> Email Archives: //www.freelists.org/archives/techassist/
>
>
>
> --
> Internal Virus Database is out-of-date.
> Checked by AVG Anti-Virus.
> Version: 7.0.298 / Virus Database: 266.4.0 - Release Date: 2/22/2005
>
>
-----------------------------------------------------------------------------
This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
Lost Password: http://www.tech-assist.org and select "Login Problems?".
Email Archives: //www.freelists.org/archives/techassist/
Other related posts:
