[TechAssist] Re: RCA D52W20, ITC222, Convergence power supply problem

  • From: Gary McCartney <gary@xxxxxxxxxxx>
  • To: techassist@xxxxxxxxxxxxx
  • Date: Thu, 04 Aug 2005 14:04:00 -0400

Digikey USA website shows TLP621G for 53 cents each




Gary McCartney

McCartney Electronics
Guelph Ontario Canada
Est. 1984
email: gary (at) number63.ca








gulftech@xxxxxxxx wrote:
> Jerry,
> 
> Where can you buy them that cheaply?  I used to buy them at Electro Sound
> for 60 cents each, but they have been out of them for over three years. 
> A check of Tritronics shows them anywhere from $1.50 to $10.00.  Most are
> about $5.00.  Even the TT-TLP621G is $1.49 each, or $1.29 for 50 or more.
>  Sorry, if it has "TT" on it, I won't buy it at all.
> 
> 
> Ken Smith
> Gulf Technical Services
> 3034 Gulf Breeze Parkway
> Gulf Breeze, FL  32563
> 850-934-8324 (Voice) 850-932-0819 (Fax)
> 
> On Tue, 26 Jul 2005 11:57:53 -0400 "J Silverman" <greentron@xxxxxxx>
> writes:
> 
>>If you buy generic ones in bulk they are only about $0.50 so it costs 
>>more
>>to test than to replace. Costs a little less to test in circuit 
>>rather than
>>removing.
>>Jerry Silverman
>>Greentron Inc
>>4 Newland Ave
>>Greenville SC 29609
>>Fax/Phone 864 232 3889
>>mail to: greentron@xxxxxxx
>>----- Original Message -----
>>From: <gulftech@xxxxxxxx>
>>To: <techassist@xxxxxxxxxxxxx>
>>Sent: Tuesday, July 26, 2005 10:07 AM
>>Subject: [TechAssist] Re: RCA D52W20, ITC222, Convergence power 
>>supply
>>problem
>>
>>
>>
>>>Jerry,
>>>
>>>That is a truly outstanding suggestion.  I have often wondered how 
>>
>>I
>>
>>>could check an opto-isolator, but usually just replaced them if I 
>>
>>had any
>>
>>>doubts.  Bet I've replaced lots needlessly.
>>>
>>>May try to build a test jig with a socket, battery, limiting 
>>
>>resistor,
>>
>>>and posts for a meter.
>>>
>>>You have helped many techs with that suggestion.
>>>
>>>Thank you,
>>>
>>>
>>>Ken Smith
>>>Gulf Technical Services
>>>3034 Gulf Breeze Parkway
>>>Gulf Breeze, FL  32563
>>>850-934-8324 (Voice) 850-932-0819 (Fax)
>>>
>>>
>>>On Sat, 23 Jul 2005 14:28:31 -0400 "J Silverman" 
>>
>><greentron@xxxxxxx>
>>
>>>writes:
>>>
>>>>That sound normal to me! If you put some current into pins 1 and 
>>
>>2,
>>
>>>>say from
>>>>an ohm meter, then you should see some ohms appear at terminals 
>>
>>3
>>
>>>>and 4, if
>>>>your meters have the right polarity.
>>>>Jerry Silverman
>>>>Greentron Inc
>>>>4 Newland Ave
>>>>Greenville SC 29609
>>>>Fax/Phone 864 232 3889
>>>>mail to: greentron@xxxxxxx
>>>>----- Original Message -----
>>>>From: <daryls_tv@xxxxxxx>
>>>>To: <techassist@xxxxxxxxxxxxx>
>>>>Sent: Saturday, July 23, 2005 1:20 AM
>>>>Subject: [TechAssist] Re: RCA D52W20, ITC222, Convergence power
>>>>supply
>>>>problem
>>>>
>>>>
>>>>
>>>>>No... I don't have any schematics on this set.
>>>>>I think I may have found the problem.  I have absolutly no
>>>>
>>>>resistance
>>>>readi=
>>>>
>>>>>ngs between pins 3 & 4 of the opt-coupler, even on high meg 
>>
>>scale.
>>
>>>>>I will post the results when the part comes in.
>>>>>Thanks,
>>>>>Daryl
>>>>>Daryl's TV
>>>>>2402 Wyoming Ave.
>>>>>El Paso, TX  79903
>>>>>915-565-9184 Voice/Fax
>>>>>daryls_tv@xxxxxxx
>>>>>www.angelfire.com/tv2/daryls_tv
>>>>>
>>>>>----- Original Message -----
>>>>>From: Damon <damoneb@xxxxxxxxxxx>
>>>>>To: techassist@xxxxxxxxxxxxx
>>>>>Subject: [TechAssist] Re: RCA D52W20, ITC222, Convergence 
>>
>>power
>>
>>>>supply
>>>>prob=
>>>>
>>>>>lem
>>>>>Date: Fri, 22 Jul 2005 22:20:41 -0500
>>>>>
>>>>>
>>>>>>=20
>>>>>>Do you have schematics? If so, one of the transistors 
>>
>>driving or
>>
>>>>being
>>>>
>>>>>>driven by the optoisolator can be jumpered (screwdriver) and
>>>>
>>>>maybe the
>>>>un=
>>>>
>>>>>it
>>>>>
>>>>>>will start, I'm pretty sure that if that's the case, 
>>
>>replacement
>>
>>>>of the
>>>>
>>>>>>board will save you some time/money.
>>>>>>=20
>>>>>>Damon B
>>>>>>Telrad Electronics
>>>>>>Fort Wayne IN
>>>>>>----- Original Message -----
>>>>>>From: <daryls_tv@xxxxxxx>
>>>>>>To: <techassist@xxxxxxxxxxxxx>
>>>>>>Sent: Friday, July 22, 2005 1:10 PM
>>>>>>Subject: [TechAssist] Re: RCA D52W20, ITC222, Convergence 
>>
>>power
>>
>>>>supply
>>>>
>>>>>>problem
>>>>>>=20
>>>>>>=20
>>>>>>
>>>>>>>After re-checking the power supply, I discovered that the
>>>>
>>>>chopper is
>>>>not
>>>>
>>>>>>os=3D
>>>>>>
>>>>>>>cillating.  I guess I was in a hurry and used the wrong 
>>
>>ground
>>
>>>>as
>>>>
>>>>>>reference.
>>>>>>
>>>>>>>I rechecked every component on the primary side and still 
>>
>>not
>>
>>>>finding
>>>>
>>>>>>anyth=3D
>>>>>>
>>>>>>>ing bad.
>>>>>>>I thought I would sub another chopper into it but I 
>>
>>couldn't
>>
>>>>find any
>>>>
>>>>>>cross=3D
>>>>>>
>>>>>>> for it.  I hate to order one and wait several days only 
>>
>>find
>>
>>>>out that
>>>>=
>>>>
>>>>>may
>>>>>
>>>>>>=3D
>>>>>>
>>>>>>>not be it.
>>>>>>>Daryl=3D20
>>>>>>>Daryl's TV
>>>>>>>2402 Wyoming Ave.
>>>>>>>El Paso, TX  79903
>>>>>>>915-565-9184 Voice/Fax
>>>>>>>daryls_tv@xxxxxxx
>>>>>>>www.angelfire.com/tv2/daryls_tv
>>>>>>>
>>>>>>>
>>>>>>>----- Original Message -----
>>>>>>>From: Damon <damoneb@xxxxxxxxxxx>
>>>>>>>To: techassist@xxxxxxxxxxxxx
>>>>>>>Subject: [TechAssist] Re: RCA D52W20, ITC222, Convergence
>>>>
>>>>power supply
>>>>
>>>>>>prob=3D
>>>>>>
>>>>>>>lem
>>>>>>>Date: Fri, 22 Jul 2005 08:00:20 -0500
>>>>>>>
>>>>>>>
>>>>>>>>=3D20
>>>>>>>>Daryl,
>>>>>>>>I have yet to see a defective convergence power supply 
>>
>>on
>>
>>>>the ITC
>>>>222,
>>>>
>>>>>>>>HOWEVER.....
>>>>>>>>The CTC 195/197 series has had intermittant conv power
>>>>
>>>>shutdown, and
>>>>=
>>>>
>>>>>the
>>>>>
>>>>>>>>board cost was cheap enough to just replace it entirely. 
>>
>>It
>>
>>>>might be
>>>>=
>>>>
>>>>>the
>>>>>
>>>>>>=3D
>>>>>>
>>>>>>>way
>>>>>>>
>>>>>>>>to go on this unit.
>>>>>>>>=3D20
>>>>>>>>On the boards I worked on, I was able to eventually see 
>>
>>it
>>
>>>>fail,
>>>>then=
>>>>
>>>>> by
>>>>>
>>>>>>>>jumpering  two leads on the primary side I was able to
>>>>
>>>>restart it
>>>>and
>>>>
>>>>>>ver=3D
>>>>>>
>>>>>>>ify
>>>>>>>
>>>>>>>>it was the smps, and it was not a "shorting" type of
>>>>
>>>>failure. The
>>>>
>>>>>>oscilla=3D
>>>>>>
>>>>>>>tor
>>>>>>>
>>>>>>>>just quits oscillating for no good reason. But in your 
>>
>>case
>>
>>>>oscillati=
>>>>
>>>>>on
>>>>>
>>>>>>>>isn't the issue, tranferring power to the secondary
>>>>
>>>>is......does the
>>>>
>>>>>>final
>>>>>>
>>>>>>>>output drive the transformer at all?
>>>>>>>>=3D20
>>>>>>>>Damon B
>>>>>>>>Telrad Electronics
>>>>>>>>Fort Wayne IN
>>>>>>>>----- Original Message -----
>>>>>>>>From: <daryls_tv@xxxxxxx>
>>>>>>>>To: <TechAssist@xxxxxxxxxxxxx>
>>>>>>>>Sent: Thursday, July 21, 2005 6:18 PM
>>>>>>>>Subject: [TechAssist] RCA D52W20, ITC222, Convergence 
>>
>>power
>>
>>>>supply
>>>>
>>>>>>problem
>>>>>>
>>>>>>>>=3D20
>>>>>>>>=3D20
>>>>>>>>
>>>>>>>>>RCA D52W20, ITC222, Convergence power supply problem
>>>>>>>>>
>>>>>>>>>Another looser here.
>>>>>>>>>Customer claims they changed channels and lost the
>>>>
>>>>convergence.
>>>>
>>>>>>>>>What I found is no control of convergence and a 
>>
>>distorted
>>
>>>>picture.
>>>>
>>>>>>>>>There are no voltages out of the convergence power 
>>
>>supply
>>
>>>>on the
>>>>
>>>>>>>>secondarie=3D3D
>>>>>>>>
>>>>>>>>>s.
>>>>>>>>>I do have power on the primary of the smps and does 
>>
>>appear
>>
>>>>to be
>>>>
>>>>>>>>oscillatin=3D3D
>>>>>>>>
>>>>>>>>>g.
>>>>>>>>>I checked all of the semi's, resistors and electro's. 
>>
>>I
>>
>>>>ohmed out
>>>>t=
>>>>
>>>>>he
>>>>>
>>>>>>>>switc=3D3D
>>>>>>>>
>>>>>>>>>h mode power transformer. I didn't find any bad
>>>>
>>>>components.
>>>>
>>>>>>>>>I hope someone has encountered this before and can 
>>
>>give a
>>
>>>>few
>>>>
>>>>>>pointers.
>>>>>>
>>>>>>>>>Thanks,
>>>>>>>>>Daryl
>>>>>>>>>Daryl's TV
>>>>>>>>>2402 Wyoming Ave.
>>>>>>>>>El Paso, TX  79903
>>>>>>>>>915-565-9184 Voice/Fax
>>>>>>>>>daryls_tv@xxxxxxx
>>>>>>>>>www.angelfire.com/tv2/daryls_tv
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>--=3D3D20
>>>>>>>>>
>>>>
>>>>___________________________________________________________
>>>>
>>>>>>>>>Sign-up for Ads Free at Mail.com
>>>>>>>>>http://promo.mail.com/adsfreejump.htm
>>>>>>>>>
>>>>>>>>
> -----------------------------------------------------------------------=
> 
>>>>>=3D
>>>>>
>>>>>>>---
>>>>>>>
>>>>>>>>---
>>>>>>>>
>>>>>>>>>This Email List is Public. Remove:
>>>>>>
>>>>>>http://www.tech-assist.org/remove.htm
>>>>>>
>>>>>>>>>Set Vacation
>>>>>>>>
>>mailto:ecartis@xxxxxxxxxxxxx?subject=3D3Dset%20techassist%20vacation
>>
>>>>>>>>>Lost Password: http://www.tech-assist.org  and select
>>>>
>>>>"Login
>>>>
>>>>>>Problems?".
>>>>>>
>>>>>>>>>Email Archives:
>>>>
>>>>//www.freelists.org/archives/techassist/
>>>>
>>>>>>>>=3D20
>>>>>>>>=3D20
>>>>>>>
> -----------------------------------------------------------------------=
> 
>>>>>--=3D
>>>>>
>>>>>>>----
>>>>>>>
>>>>>>>>This Email List is Public. Remove:
>>>>
>>>>http://www.tech-assist.org/remove.=
>>>>
>>>>>htm
>>>>>
>>>>>>>>Set Vacation
>>>>>>
>>mailto:ecartis@xxxxxxxxxxxxx?subject=3D3Dset%20techassist%20va=3D
>>
>>>>>>>cation
>>>>>>>
>>>>>>>>Lost Password: http://www.tech-assist.org  and select 
>>
>>"Login
>>
>>>>Problems=
>>>>
>>>>>?".
>>>>>
>>>>>>>>Email Archives:
>>>>
>>>>//www.freelists.org/archives/techassist/
>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>--=3D20
>>>>>>>
>>
>>___________________________________________________________
>>
>>>>>>>Sign-up for Ads Free at Mail.com
>>>>>>>http://promo.mail.com/adsfreejump.htm
>>>>>>>
>>>>>>
> -----------------------------------------------------------------------=
> 
>>>>>---
>>>>>
>>>>>>---
>>>>>>
>>>>>>>This Email List is Public. Remove:
>>>>
>>>>http://www.tech-assist.org/remove.htm
>>>>
>>>>>>>Set Vacation
>>>>>>
>>mailto:ecartis@xxxxxxxxxxxxx?subject=3Dset%20techassist%20vacation
>>
>>>>>>>Lost Password: http://www.tech-assist.org  and select 
>>
>>"Login
>>
>>>>Problems?".
>>>>
>>>>>>>Email Archives: 
>>
>>//www.freelists.org/archives/techassist/
>>
>>>>>>=20
>>>>>>=20
>>>>>
>>>>>
> -------------------------------------------------------------------------
> 
>>>=
>>>
>>>>>----
>>>>>
>>>>>>This Email List is Public. Remove:
>>>>
>>>>http://www.tech-assist.org/remove.htm
>>>>
>>>>>>Set Vacation
>>>>
>>>>mailto:ecartis@xxxxxxxxxxxxx?subject=3Dset%20techassist%20va=
>>>>
>>>>>cation
>>>>>
>>>>>>Lost Password: http://www.tech-assist.org  and select "Login
>>>>
>>>>Problems?".
>>>>
>>>>>>Email Archives: 
>>
>>//www.freelists.org/archives/techassist/
>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>--=20
>>>>>___________________________________________________________
>>>>>Sign-up for Ads Free at Mail.com
>>>>>http://promo.mail.com/adsfreejump.htm
>>>>>
>>>>>
>>>>
> -------------------------------------------------------------------------
> 
>>>-
>>>
>>>>---
>>>>
>>>>>This Email List is Public. Remove:
>>>>
>>>>http://www.tech-assist.org/remove.htm
>>>>
>>>>>Set Vacation
>>>>
>>>>mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation
>>>>
>>>>>Lost Password: http://www.tech-assist.org  and select "Login
>>>>
>>>>Problems?".
>>>>
>>>>>Email Archives: //www.freelists.org/archives/techassist/
>>>>
>>>>
> -------------------------------------------------------------------------
> 
>>>----
>>>
>>>>This Email List is Public. Remove:
>>>>http://www.tech-assist.org/remove.htm
>>>>Set Vacation
>>>>mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation
>>>>Lost Password: http://www.tech-assist.org  and select "Login
>>>>Problems?".
>>>>Email Archives: //www.freelists.org/archives/techassist/
>>>>
>>>>
>>>
> -------------------------------------------------------------------------
> -
> 
>>---
>>
>>>This Email List is Public. Remove: 
>>
>>http://www.tech-assist.org/remove.htm
>>
>>>Set Vacation
>>
>>mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation
>>
>>>Lost Password: http://www.tech-assist.org  and select "Login 
>>
>>Problems?".
>>
>>>Email Archives: //www.freelists.org/archives/techassist/
>>
>>
> -------------------------------------------------------------------------
> ----
> 
>>This Email List is Public. Remove: 
>>http://www.tech-assist.org/remove.htm
>>Set Vacation 
>>mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation
>>Lost Password: http://www.tech-assist.org  and select "Login 
>>Problems?".
>>Email Archives: //www.freelists.org/archives/techassist/
>>
>>
> 
> -----------------------------------------------------------------------------
> This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
> Set Vacation mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation
> Lost Password: http://www.tech-assist.org  and select "Login Problems?".
> Email Archives: //www.freelists.org/archives/techassist/
> 

-----------------------------------------------------------------------------
This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
Set Vacation mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation
Lost Password: http://www.tech-assist.org  and select "Login Problems?".
Email Archives: //www.freelists.org/archives/techassist/

Other related posts:

  1. Home
  2. techassist
  3. Archive
  4. 08-2005