Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco turntable fries 7R7 tube in 47-1230
#1

I have completed full re-cap on a customers Philco 47-1230. I cleaned the Push Button section, and phono switch, & all is working great.
Today, after playing the radio over 20 hrs since restoration working great on all bands, something weird happened. I attached the phono a.c. plug 2-pin connector to see if phono motor would turn, and let the old phono motor run for a short amt of time. After some help by hand, the old motor started turning. In the process of doing that, the radio quit working. I had the old phono mono input rca attached, but the tonearm not connected thru the old hi-imp transformer mounted in fnt bottom of cabinet.
Anyways, the radio receiver shut down, but still had some audio on higher volume. After tapping on the tubes, I found the n.o.s. 7R7 tube I just purchased and played over 20 hrs testing from AES was very microphonic. I replaced the 7R7 tube, and the Radio receiver started working again.
My question is this, did the turntable motor pass some AC current via orig input wire back into the chassis to take out the nos 7R7 tube? Since I replaced the tube, everythings working fine in the radio again. I have unplugged the phono ac line output plug from chassis, and when I engage the phono pushbutton , everything is fine with just the phono RCA input still connected. Now I can engage & release the phono button without any harm to the radio. I really dont think the prob is in the phono ac switch. For now, I will leave the phono ac connector disconnected altogether. Without pulling out the schematic again, this doesnt compute for me right now? Anyone ever had this prob happen before? Thanks for your thoughts, Im overlooking something simple here on the Philco 47-1230 chassis. Randal


Messages In This Thread
Philco turntable fries 7R7 tube in 47-1230 - by Texasrocker - 01-20-2009, 02:36 AM
Re: Philco turntable fries 7R7 tube in 47-1230 - by Guest - 01-27-2010, 08:47 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco model 38 code 121 not receiving signal.
Congrats on your success Stormlord. My rough guess is that since both the 15 and the 1A6 are supposed to be shielded, I...MrFixr55 — 10:04 PM
The list of my radio & TV collection!
A little light Saturday positive about our hobby in our feed... My new every Saturday video about antique radio equipme...RadioSvit — 02:12 PM
Model 70 Cabinet Trim
musar , Well if you have any more questions feel free to post away . Sincerely Richardradiorich — 08:56 PM
Model 70 Cabinet Trim
Although I have not made any cabinets or cabinet parts for a couple of years, I still have some parts left over, includi...Steve Davis — 06:26 PM
philcorepairbench.com - shadow-meter
Thanks Ron. But I can't find those articles.fenbach — 02:43 PM
Model 70 Cabinet Trim
Thank you, Gary. Before making my original post, I had clicked on "Steve Davis Cabinets" only to find that it...musar — 02:25 PM
philco predicta
Welcome to the Phorum, cgl18! I am not your resource for television repair, but lots of friendly help is available here...GarySP — 02:12 PM
Model 70 Cabinet Trim
Welcome to the Phorum, musar! You can send Steve Davis a private message (PM). The site is at the top of the Home page...GarySP — 02:09 PM
Model 70 Cabinet Trim
How do I contact him? The only contact information for him I could find when searching online was a telephone number th...musar — 10:38 AM
philco predicta
Hello, good afternoon, I would like to ask what the possible problem could be if I don't have an image on the screen. I ...cgl18 — 10:19 AM

[-]
Who's Online
There are currently no members online.

>