[TechAssist] Re: CTC177-no tuning voltage from PLL IC
- From: Jorge Camboni <geo@xxxxxxxxxxxxx>
- To: techassist@xxxxxxxxxxxxx
- Date: Fri, 29 Nov 2002 02:27:19 -0600
Hi Richard. Had a similar problem with another 177. Tuning voltaged
remained on 33v no matter what I did (pins 7, 8 and 14 on IC 7501.
After scratching my head and squeezing my brain for a few months
I found R7408 open (maybe while resoldering the whole tuner it
did not stand the heath) Its value is 37.4 K 1%
(39k will do extremely fine) That resistor is part of the voltage
divider (1M from 33v, 37k to ground) that feeds the pll transistor's
collector through R7401 (191k). All smd's
Good luck
Jorge, GY Electronics, Richardson/Dallas
At 08:58 p.m. 28/11/02 -0500, "Richard La Placa"
<continentaltv@xxxxxxxxxxx> wrote:
>Hello all,
>Hope everybody had a great Thanksgiving day.
>The pll transistor has 30 volts on the collector no matter what channel I
>select. The band switch works perfect, I can put a pot from the col to the
>gnd and get all channels on every band. I changed the PLL IC & crystal, the
>mixer IC, the eeprom & micro, resoldered the tuner, checked the voltages at
>all the ic pins, checked the diodes and resistors in the feedback circuit
>and no luck.The clock and data lines must be ok because the PLL IC is
>switching bands.Could I have another bad PLL IC?, or has anybody seen some
>other part here?
>Thanks,
>
>Richard La Placa
>Continental TV
>312a Park Row
>Chestertown, Md,21620
>Fax&Phone-410-778-1113
>continentaltv@xxxxxxxxxxx
>
>
>
>
>_________________________________________________________________
>Protect your PC - get McAfee.com VirusScan Online
>http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
>
>------------------------------------------
>To REMOVE your email address, click here:
> http://www.tech-assist.org/unsubb.html
>To CHANGE your email address, click here:
> http://www.techassist.net/forms/change.html
>------------------------------------------
>***NEW*** Tips Added Instantly!!!***
>Submit Repair Tips here:
>http://www.tech-assist.org/secure/tip/
Jorge Camboni, GY Electronics, Dallas
------------------------------------------
To REMOVE your email address, click here:
http://www.tech-assist.org/unsubb.html
To CHANGE your email address, click here:
http://www.techassist.net/forms/change.html
------------------------------------------
***NEW*** Tips Added Instantly!!!***
Submit Repair Tips here:
http://www.tech-assist.org/secure/tip/
Other related posts:
