Forum: Troubleshooting Audio Equipment
05-18-2022, 10:28 PM
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Replies: 2
Views: 63
Re: Lafayette LR-20 MPX Board
Nope T14 has the metal shield and slug missing. coil is busted and measures infinite or open. Found a 8.6 mH coil on Digikey for $2.42, however shipping charge $25.00. So I hope it will adjust from...
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Forum: Troubleshooting Audio Equipment
05-17-2022, 04:25 PM
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Replies: 2
Views: 63
Lafayette LR-20 MPX Board
Needing some help to get this MPX board working again. General investigation shows a busted variable inductor location T14. Looking at the schematic T14 and T15 are the same inductance value....
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Forum: Equipment Usage, Soldering, Techniques, and Reviews
10-17-2021, 06:06 PM
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Replies: 8
Views: 1,002
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Forum: Equipment Usage, Soldering, Techniques, and Reviews
10-17-2021, 06:02 PM
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Replies: 8
Views: 1,002
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Forum: Equipment Usage, Soldering, Techniques, and Reviews
10-15-2021, 06:26 AM
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Replies: 8
Views: 1,002
Re: Radio Shack 2200813 29 range DVM
Yes the other ranges seem to work. I don't see any way to zero the ohms out as the meter reads about 46.7 ohms when leads are shorted. I'll send some more pictures of the main motherboard and some...
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Forum: Equipment Usage, Soldering, Techniques, and Reviews
10-07-2021, 08:08 PM
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Replies: 8
Views: 1,002
Radio Shack 2200813 29 range DVM
Does anyone have any information for a Radio Shack 2200813 meter. I need to know what value R14 was. Mine is measuring 90 ohms. My meter did have a blown fuse F1 rated at 250V @ 500mA. Symptoms are...
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Forum: Troubleshooting TVs and Video Sources
08-05-2021, 02:11 PM
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Replies: 8
Views: 700
Re: Ocosmo E32 Backlight LED Replacement
These are the finished panels. I used a high gloss white enamel paint and then used a urethane clear glue to attach the lenses.
If you're wondering why the center panel is a little off white after...
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Forum: Troubleshooting TVs and Video Sources
08-03-2021, 07:18 PM
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Replies: 8
Views: 700
Re: Ocosmo E32 Backlight LED Replacement
Update: I took your advice and replaced all 21 LED's. I used my Hakko FR-801 set on heat range 4 and air at 10. Each lens popped off in a few seconds and just dressed up solder pads with fresh...
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Forum: Troubleshooting TVs and Video Sources
07-28-2021, 01:20 PM
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Replies: 8
Views: 700
Re: Ocosmo E32 Backlight LED Replacement
Looks as I have found some that will work. All 3 for $12.35 from ebay.
Product information
Condition: Brand NEW
Size (Length): 630mm
Number of LED beads: 7 per strip
Every...
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Forum: Troubleshooting TVs and Video Sources
07-27-2021, 02:07 PM
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Replies: 8
Views: 700
Ocosmo E32 Backlight LED Replacement
Hello all reading this post. I have an Ocosmo E32 TV and have isolated the backlight problem to one defective LED. Testing the good LED strips I have found that each LED drops about 3.0VDC across it....
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Forum: Troubleshooting Audio Equipment
07-19-2021, 04:54 PM
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Replies: 12
Views: 3,372
Re: Jvc pc-x100
Success, Yes the CD player worked and I am convinced that plugging in the wrong wiring harnesses to optical pickup will render it useless. I had to some alignment calibration for tracking monitoring...
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Forum: Troubleshooting Audio Equipment
07-11-2021, 05:17 PM
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Replies: 12
Views: 3,372
Re: Jvc pc-x100
Update: I believe I have isolated the problem. It would seem that the laser pickup has two identical interconnection sockets that are 8 pins each. One is red for the laser and the other white for the...
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Forum: Troubleshooting Audio Equipment
07-01-2021, 08:40 PM
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Replies: 3
Views: 2,378
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Forum: Troubleshooting Audio Equipment
07-01-2021, 05:35 PM
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Replies: 3
Views: 2,378
Re: Need schematic for JVC PC-X100
I just bought one and it has some wrong values for resistor values in the cd section, but for the most part it is accurate. I can send the PDF service manual if you need it? Please check your message...
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Forum: General Electronics Technical Discussion
07-01-2021, 05:30 PM
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Replies: 18
Views: 1,173
Re: ECH81/6AJ8 Vacuum Tube Question
Update: Rebuilt FM front end replaced all dog bone capacitors with multi layer ceramic capacitors at 1% tolerance. Main defect was the 8.2pF and 20pF in the tank circuits for the mixer oscillator....
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Forum: Troubleshooting Audio Equipment
06-23-2021, 07:20 PM
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Replies: 12
Views: 3,372
Re: Jvc pc-x100
I have successfully replaced the main IC's IC 602, and IC 603. The chips lifted quite nice and no traces tore up. The new ones went down well, but no spindle rotation.All I get on the display is CD...
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Forum: General Electronics Technical Discussion
06-20-2021, 07:02 PM
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Replies: 18
Views: 1,173
Re: ECH81/6AJ8 Vacuum Tube Question
The tuner front end is straight forward the components are soldered point to point. I am de soldering all the capacitors, but my Sencore LC103 does test capacitors in circuit. It has never given...
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Forum: General Electronics Technical Discussion
06-19-2021, 02:53 PM
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Replies: 18
Views: 1,173
Re: ECH81/6AJ8 Vacuum Tube Question
Well I took the painstaking task of disassembly of the FM front end and boy oh boy every capacitor is well out of tolerance and value. Using reactance formula it seems that the impedance increases as...
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Forum: General Electronics Technical Discussion
06-17-2021, 06:58 PM
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Replies: 18
Views: 1,173
Re: ECH81/6AJ8 Vacuum Tube Question
My replacement ECH81/6AJ8 arrived today and yes AM is now superhetrodyning again. Getting very good sensitivity from 1600Khz to about 630Khz with just the loop antenna. Magic eye now shows center...
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Forum: General Electronics Technical Discussion
06-16-2021, 07:02 PM
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Replies: 18
Views: 1,173
Re: ECH81/6AJ8 Vacuum Tube Question
I'm attaching the schematic and will note the 22V voltage drop for each anode of the rectifier tube. The schematic shows a 300 ohm @ 5watt resistor. Once I measure first the actual resistance and...
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Forum: General Electronics Technical Discussion
06-15-2021, 05:38 PM
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Replies: 18
Views: 1,173
Re: ECH81/6AJ8 Vacuum Tube Question
Going back to the rectifier tube section. You mentioned that the rectifier tube drops more voltage than the standard 0.6Vdc drop of a silicon diode. So it would be a wise assumption to first measure...
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Forum: Troubleshooting Audio Equipment
06-11-2021, 07:40 PM
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Replies: 12
Views: 3,372
Re: Jvc pc-x100
I checked some specs for the pickup and think I found the problem. It appears that the Sony KSS-210b must be replaced with the same type laser pickup optical assembly. The unit I had was a KSS-201a...
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Forum: General Electronics Technical Discussion
06-10-2021, 05:49 PM
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Replies: 18
Views: 1,173
ECH81/6AJ8 Vacuum Tube Question
Recently I acquired an Eico HFT 92 AM/FM radio made back in 1958. The unit has had some decent modifications done such as replacing the rectifier tube with silicon diodes and replacing the main...
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Forum: Troubleshooting Audio Equipment
06-05-2021, 07:48 PM
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Replies: 12
Views: 3,372
Re: Jvc pc-x100
Update the spindle does rotate, but LCD display just shows all zero's and disc stops rotating. At this point I will need to get a service schematic and check all voltages and wave forms going to the...
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Forum: Troubleshooting Audio Equipment
06-05-2021, 03:45 PM
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Replies: 12
Views: 3,372
Re: Jvc pc-x100
You were absolutely correct. There is a solder bridge I will remove it with my pace solder extractor and verify short is removed with DVM in resistance mode. I will reassemble cd unit and see it the...
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