Is this components safe as a replacement?

Thread Starter

Djedd85

Joined Jul 27, 2019
5
Good afternoon everyone.
New to the forum here, but have been reading alot on here over the years. I need a bit of help please. I'm currently in the process of repairing a Telefunken CRT Tv.

One evening the Tv just stopped working. The guy who's Tv it was said after it stopped working, it kept blowing the fuse so he replaced the plug only.

When I checked the plug I saw that he swopped the blue (N) and live (B) wires. So I fixed that.

Upon opening the tv I found the following -
A popped In-rush current protector with a piece of fuse stuck between one of the legs and the degauss coil connector. I have to mention tho that the black wire of the degauss coil is broken from the connector itself and isn't insulated anymore and the piece from the fuse was stuck here.

2x Of the Diodes from the brigde rectifier was shorted.
So before I go further, I originally thought this was the a actual problem and I replaced those 2 parts with -
In-rush current protector:
MF72 7D13 -> SCK13104MSY

Brigde rectifier:
RL207 -> 1N5408

After replacement I did the light bulb trick and the light shined bright with the degauss coil plugged in and it shined dim when it was plugged out.
So I thought the problem was fixed.I plugged in the Tv and.... Nothing.Not even the red power light came on. Atleast it didn't blow fuses anymore. So I did another light test, but now the bulb shines dim and goes dead. I guessing this is the high voltage cap charging. But the light just stays off after that.

So in I went again.After furthe testing i found a shorted H.O.T and also the driver transistor was gone as in bad. I replaced these 2 parts with the following-
D5107 -> BU508A
C3807 -> C3807
Also the octocoupler
B0834 -> P621

Also on the secondary I found a shorted diode again which is a HER308.

My questions are-
Was it safe to replace the in-rush current protector and brigde rectifier with higher rated components.
Also the last few parts I replaced with others from some junk old tv boards that was lying around.Will those be ok?

Last question with what can I replace the HER308 Diode?

Thanks.
 

Alec_t

Joined Sep 17, 2013
10,429
Was it safe to replace the in-rush current protector and brigde rectifier with higher rated components.
Depends what you mean by 'higher rated'. For example, replacing a component designed to limit in-rush current to 1A by one designed for a 10A current limit would not be advisable, whereas a 10A rated rectifier would be fine as a replacement for a 2A one.
 

Thread Starter

Djedd85

Joined Jul 27, 2019
5
Depends what you mean by 'higher rated'. For example, replacing a component designed to limit in-rush current to 1A by one designed for a 10A current limit would not be advisable, whereas a 10A rated rectifier would be fine as a replacement for a 2A one.
Hi @Alec_t, thanks for your reply. So I have got hold on most of these component datasheets except for 2 or 3 of them. Here are the info.
Thermistor-


Diodes



Transistors

Unable to find anything on the D5107 transistor. Hope you can help me out on this.

Octocouplers




There is another octocoupler with the code 8187 on it that I'm not getting any info on and then also the Diode HER308 that I need a replacement for.
Can I use the 1N5408 as a replacement for the HER308?
Even if the HER is rated at 600V and the 1N5408 is 1000V?
 

Thread Starter

Djedd85

Joined Jul 27, 2019
5
Sorry about the post above. I took to long to edit. How can I interest screenshots into the post?

Here is another edit with links to the screenshots.

Depends what you mean by 'higher rated'. For example, replacing a component designed to limit in-rush current to 1A by one designed for a 10A current limit would not be advisable, whereas a 10A rated rectifier would be fine as a replacement for a 2A one.
Hi @Alec_t, thanks for your reply. So I have got hold on most of these component datasheets except for 2 or 3 of them. Here are the info.
Thermistor-
http://imgur.com/a/eusx2tx

Diodes
http://imgur.com/aLWz7gJ
http://imgur.com/gallery/4zBrxV7

Transistors
http://imgur.com/GRqOHWb
Unable to find anything on the D5107 transistor. Hope you can help me out on this?

Octocouplers
http://imgur.com/3LqCU54
http://imgur.com/sXjpfDg
http://imgur.com/PI6Tzki
http://imgur.com/YOdiyQW

There is another octocoupler with the code 8187 on it that I'm not getting any info on and then also the Diode HER308 that I need a replacement for.

Can I use the 1N5408 as a replacement for the HER308?
Even if the HER is rated at 600V and the 1N5408 is 1000V?
 
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