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Zsuttle 07-11-2018 01:16 PM

Motorola TS-4J
 
Can someone confirm what should attach to the selenium rectifiers? Someone replaced mine but there are a lot of loose connections and I'm not sure what goes where. The schematics don't match the spare chassis I have (TS-4J as well).

Thanks,
Zach

bandersen 07-11-2018 04:35 PM

I've restored several of these and the published schematics are correct. What differences are you seeing in your spare chassis ?

Zsuttle 07-11-2018 05:21 PM

2 Attachment(s)
Quote:

Originally Posted by bandersen (Post 3201888)
I've restored several of these and the published schematics are correct. What differences are you seeing in your spare chassis ?

Maybe I'm reading this wrong, but the positives of C2A and C1 should never touch right?
Attachment 197382

Attachment 197383
This is the actual wiring of the spare. I realize this isn't in proper schematic form, but I didn't wanna confuse myself.

bandersen 07-11-2018 05:25 PM

Right the positives do not touch - the rectifier goes in between. Your spare isn't wired right. Maybe someone was trying to fix it ?

Zsuttle 07-11-2018 06:41 PM

We can only guess. The spare had numerous evident repairs. It blew both the diodes when I installed it in the main chassis, but hopefully all of the caps are still within tolerance.

timmy 07-12-2018 06:37 AM

Quote:

Originally Posted by Zsuttle (Post 3201892)
We can only guess. The spare had numerous evident repairs. It blew both the diodes when I installed it in the main chassis, but hopefully all of the caps are still within tolerance.

If the caps you mention you hope are still good, then if they are original they won't be.

Electronic M 07-12-2018 11:21 AM

Quote:

Originally Posted by timmy (Post 3201902)
If the caps you mention you hope are still good, then if they are original they won't be.

Even if those caps are new if the wiring errors put reverse polarity or AC across any of those caps the ones that got it are done for.

kvflyer 07-12-2018 05:26 PM

Quote:

Originally Posted by Electronic M (Post 3201909)
Even if those caps are new if the wiring errors put reverse polarity or AC across any of those caps the ones that got it are done for.

And if you don't take that into consideration, you may have headaches in the future. I realise it is difficult to throw away a "new" capacitor. But they are really not that expensive and there is security in knowing that they are new, and not stressed.

Zsuttle 07-12-2018 08:43 PM

Yeah, today I purchased new electrolytics for all but one of the caps.(The only two that tested good were either before the diodes, or not in the power circuit.) Since I elected to restuff, it should be fairly easy to replace them without unsoldering the whole can, just cutting and resoldering the leads. My parts store didn't have some of the values, so I'll have to make do with a few caps that are higher value (eg a 150uF instead of a 120uF) but it should be alright until I get permanent replacements.

Zsuttle 07-12-2018 10:48 PM

Well this is intresting, the tubes failed to light, but then I found out that the grounds on the caps weren't connecting properly. After a quick fix, still no high voltage, but all of the tubes were once again lighting properly. When I test the Caps after a quick power on they test alright, but after sitting for some time they test way out of specs. What keeps blowing my caps? How do I troubleshoot this? Both of the diodes appear to have shorted once again as well.

timmy 07-13-2018 09:36 AM

Start from scratch with the schematic. There are 2 diodes, maybe one was put in backwards. The grounds go to different places so they cannot be tied together. IIRC one cathode end of one diode goes to the ballast, pin5 , and the other to pin 4 of the ballast provided you are using the correct ballast . The cathode end of the diode going to pin 5 now continues to the positive end of the second diode. Check that schematic it's all there as it could be a simple mistake or a wire in the wrong place. I have 7 of these sets and had my share of stupid mistakes. :smoke:

Zsuttle 07-13-2018 09:06 PM

http://www.videokarma.org/attachment...2&d=1531347472

I might have found the culprit. If C79 has failed that would be enough to short the circuit, right? Its capacitance is way off and it tests at 190ohms. What type of cap should I replace this with and with what voltage?

mrjukebox160 07-13-2018 09:21 PM

If C79 shorted the 200 ohm part of the ballast resistor should of burned up very quickly.

Zsuttle 07-13-2018 09:33 PM

Quote:

Originally Posted by mrjukebox160 (Post 3201949)
If C79 shorted the 200 ohm part of the ballast resistor should of burned up very quickly.

If that isn't the case, if anything at all had shorted, then the ballast should be blown right?

What should the voltage coming off of pin 4 and pin 3 be?

timmy 07-14-2018 06:53 AM

I don't find a c79 power supply cap on the ts4j schematic.


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