Electronics Repair FAQ & Testimonials- Part 29
By · Comments
can i replace the diode (RL-205) with (RL-207)
because i our area RL205 is not available and RL207 has 1000 peak reverse voltage while RL-205 has 600 peak reverse coltage…..
please replay me
regards
R.mohammed ali
Hi Mohammed,
If the ampere is the same yes you can replace it.
Jestine
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Hi ! Jestine first of all I would like to thanks for which you was sending last time.in this week I was test sony tv the problem of it’s on power supply board .The problem of it’s as follows :, fuse , resistor 470 k ohm and power regulator transistor c3550 blowed (birned) even though I have been got these problem I can’t repair becouse of power regulator transistor c3550 problem . the plame is I cant get it in the shop by it number, so can you tel me the equvalent of these transistor .
Thanks
Electronics Repair FAQ & Testimonials- Part 28
By · CommentsHi,
Jestine thanks for your reply. How can I check if the power supply is stable bcz I don’t have any oscilloscope meter,but I have a sanwa meter CX 506A where I can trace any defect in cap [ESR].I’ve already change all the cap in the ps.I’m sure that the ps is not ok but don’t know where is the culprit?
Thanks and regards…………..
Hi Bobby,
If you get the exact voltage from your meter and the needle did not move (constant) then you know you have a good and stable voltage.
Jestine
Electronics Repair FAQ and Testimonials- Part 27
By · Commentshi jestine
thanks for the reminders i have been to one or more of those sites get what i need and quite then later try finding the sites but all usually in vain,now jestine i have a sony ctv model 2197m3s that has all red colouring from raster to showing images i have checked the c2611 trnsistors and the corresponding resistors but they look ok so im staarting to doubt the tda8375a before i go further anyadvise would be most apreciared
HI James,
I suggest that you compare the Green and blue transistor at the CRT board for voltage and signal (waveform) with Red circuit. Any difference in voltage or the signal is the clue for you to start troubleshoot at that particular section.
Electronics Repair FAQ & Testimonials-Part 26
By · CommentsHi Jestine ,
Can i check with you , if i measure the VCC pin of the power ic UC3842 and i get the reading not constantly example 11.xx dcv jump to 14.xx dcv then go down to 12.xx dcv and then up again , normally which parts did i need to check . Thanks
HI Chong,
It can be the IC itself have problem, the supply vcc line e-cap ESR value have shoot up or even if there is components shorted in the secondary side preventing the ic to start up. I suggest that you check all secondary output diodes first and filer caps, then optoisolator ic then back to the power ic. Sometimes corresponding components to the power ic also could have problem
Electronics Repair FAQ And Testimonials- Part 25
By · CommentsHi Jestine!
Good day!
Thanks a lot for your e-mail.
I’m so glad and happy to tell you that I have already repaired a number of electronic equipment with the help of your ebooks.
It’s not only profitable but the joy of self-achievement are wonderful.
Thanks again and I wish you and your family good health and more power to you on your career!
With my best regards,
George
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What should new electronic technicians do
when they come across older electronic devices or equipment with obsolete components?
like for example
lets say you have a circuit board that was assemble in the early 1980s. the part that needs replacing is a transistor.
how many times does this old transistor
part number has to be cross referenced from the late 1980s, 1990s,2000 etc.
will the part number on that old transistor be in todays cross reference book?
Electronics Repair FAQ And Testimonials- Part 24
By · CommentsHI Roland,
Good day Jestine,
Good day!
I would just like to inquire with regards to a burned varistor. I had a electronic control board that has burned varistor and the part number was also
burned. Is there any way or technique that I can do to replace the burned varistor. i have measured the varistor and has a value of 27ohms which is i believe that is shorted and keeps on blowing the fuse.
Yes you are right by right it should not have any reading.
Electronics Repair FAQ and Testimonials-Part 23
By · CommentsHi Gasant,
1) Does the transformer supply the Drain leg of Fet with power
The drain is just like a switch controlled by the gate and the supply is coming from the transformer.
2) Does the Drain leg of the Fet make the run dc circuit.
Run dc ac signal source is from one of the output of the secondary winding in primary side. The primary winding have to be energized in order to get the ac signal source from the secondary winding.
Electronics Repair Faq and Testimonials -Part 22
By · Commentshi
long time and happy new year, we are doing well in KENYA. i need help on this LCD monitor and i have seen this problem on Lcd Tv eg if I type the letter A on MS Word, there will be a shawdow A next to it.
HI Ibu,
Thanks and happy new year to you too. In your case if all the output voltages are good and stable then the problem is in the lcd panel. Try reflow the lcd controller/t-con board and if still the same then you may need to replace the LCD panel.