Friday, July 1, 2011

Customer support

 Here is a small conversation between me and a new customer Mr Roger from Philippines

Roger : sir, thanks for the reply, I really  amazed by your eBook, it’s very nice as a beginner in this fields of electronics, sir, can i ask you about my 14inch. TV polytron, no audio and no picture, when I switch on only horizontal lines appear from top to bottom ,pls. advise me sir..Thanks...God bless....

Humphrey: For the TV with retrace lines...First adjust the screen voltage on the fly back transformer bottom knob (refer to chap 11 of your eBook and see if they disappear) also check the RGB supply voltage (see details on chap 13 of your book). Please relax and read the book slowly and carefully...don't rush... for the other TV...try another connector for the DVD but make sure yellow connector on TV go to yellow connector on DVD. Yellow is always for video..... Also be sure the TV is set to A/V mode.

Roger :sir, good day, I check already, this polytron 14,,the supply coming from the flyback,,,when I do voltage testing got only 156v, supposed to be 185v am I right? sir?, may I share to you the history when first check this TV, I re- soldered dry joints at the fly back...and i adjust the screen knob, and the TV was ok, but after 5days the fault is back to his former fault, as of now I test also all secondary output voltages but I notice some readings low...I try your advice to check the voltages at the RGB at CRT neck board if i have of now i try to adjust the screen knob, but only the brightness going up and down but no display appear read your book as of now, it’s very nice book sir,,,

Humphrey: Now we are getting somewhere...the 156  volts for RGB supply voltage  is definitely low...this could point to a filter capacitor for that line that has developed high ESR (dry up) please replace the filter capacitor for that line(usually rated 250 volts in your case 4.7uF/250V and change that directly...also if you disconnect one of its leg from the circuit and the voltage goes up means indeed it is faulty...please be sure you have come back to me with the progress. Again remember you adjusted the screen voltage upwards and therefore you will need to bring it down so that the line should fade away.

Attached please see the diagram for more info.

Best of luck Roger

Roger : ok sir, ill check the caps,,,,thanks

Humphrey: This TV should be working by now....see the pic for more details...

Roger : sir, thanks, very nice support, sir I check my TV ,i check the supply coming from the fly back, I trace the e-caps rated 2.2uf/250v,,the track is broken, intermittent, so I fix that line, but accidentally when i switch ON there is smoke little, coming from the e-caps rated 470uf/25v...because my jumper line to the broken track accidentally touch to the 2.2 uf/250v e-caps..I immediately fix the line, but the 470uf/25v is already gone, so I will purchase today to fix again this TV, hehhehe,,i think this is my lesson,,,  but sir, I didn’t see any e-caps rated 4.7uf/ the tv board  ,,,, i see 10uf/250v at the crt neck board only...but i really appreciate your effort for me sir, but I’ll try myself, as of now i continue read your book, it’s very detailed book..if i fix my TV, i inform you immediately.....big thanks...sir.God bless,,,,,.

Humphrey: I can see you are progressing well; sure the caps are usually rated between 2.2 uF/250V to 10uF/250v.... the working voltage is usually please change the two caps with the rating of 250V
Good luck ……Still waiting for your success report.

Roger : sir, good day, good news, the tv is working now sir, but before that i replace the caps,,the voltages is 156 only at the crt neck board,,,the output of fbt is only 113v...after the diode and the caps,,it read 156v,,so the tv has re trace lines again after replacements of caps, so I conduct my analysis, cos,i already finish read your book, i check also the voltage at the B positive is 112v,,,but when i check the e-caps of that line 220uf/160v,,its 113v only,,,so i replace also that e-caps,,,and i double check the terminal of fbt...i resolder also i sw. on the tv,,,i adjusted the focus to low,,and turn the screen also slowly to low,the picture appear, now i test run the tv for 4-5 hours is ok,,,,heres the photo sir, thank you sir for the support , now i really amazed the crt book...especially the smps function,,,bcos,,of your book sir,,its very nice information,,,,,,

Humphrey: Thanks for that good reports...I can see you are really getting on pretty well. usually in electronics it is important sometimes to think outside the box...i have noted you are doing exactly that...whenever you notice a lower voltage than expected always suspect a capacitor which has its esr gone up...To test such capacitors you will need an esr meter.

This i highly recommend it to you because it will make your troubleshooting quite easy...if you don’t have one please note that you can make one easily from the last month article from Jestine yong on how to make your own esr meter.

if you find the problem with that tv has come back again..Still it could point to a bad capacitor still not picked up.

all the best



  2. Hi Beh,Thanks for your feedback.
    Regards Humphrey

  3. HI Humphrey,
    Good customer service/support will bring a good reputation to you and your company.


  4. Hi Jestine, Thanks you for passing by and very positive remarks.

    Regards Humphrey