This is the journey of Jestine Yong in Electronic Repairing. On this blog, you’ll find his Electronic Repairing experiences, tips, tricks, guide & recommendations. Feel free to browse around the blog and absorb as much electronic repair tips as you could. Thanks for visiting!
This is the journey of Jestine Yong in Electronic Repairing. In this blog, you’ll find his Electronic Repairing experiences, tips, tricks, guide & recommendations. Feel free to browse around the blog and absorb as much electronic repair tips as you could. Thanks for visiting!
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September 8th, 2007 at 8:13 am eDear Jestine,
I read your article regarding trouble shooting DELL LCD monitor E173FPB, I follow your recommendation by replacing 4 transistor sc5707, the monitor working well but only few hours after that coming to power blinking system. I replaced again all the transistor but only running few hours. Do you have any idea what would be the faulty component which can cause short life of the transistor. Appreciate for your assistance on this issue.
Regards
September 8th, 2007 at 1:29 pm eHi Herman,
The reason why the C5707 transistors brekdown was due to tiny dry joints in the high voltage transformer. Resolder all of the high voltage transformers and i’m sure the problem would be solved. Also you must replace back with the same part number transistor ie; C5707.
September 12th, 2007 at 8:41 am eDear Justine,
I follow your advice, resolder all the high voltage transformer and replace 4 transistor one more time. I turn on the monitor, it stay a few second after that display goes blank (black) the power button stay on green ( no blinking ). I turn off and on again but same thing happen. I check the 4 transistor and it’s ok.
Any idea ?
Thanks for your assistance.
Regards,
September 13th, 2007 at 8:42 am eHi,
When the display go blank, did the supply voltage to the inverter ic tl1451acn also down? If yes, then most probably is the main board fault as no signal trigger the start circuit causing no voltage flowing to the inverter ic. Did you replace transistors with original part number c5707?
Jestine
September 15th, 2007 at 4:08 am eJestine,
I cehck the power supply of pin 9 ic tl1451acn and is ok ( 16 volt), check fuse also ok. I replace the transistor with original part number C5707, so far transistor still ok. Do you think problem with IC tl1451acn ?
I try to connect with computer, display only few second and then goes blank, plug out and plug in again samething happen.
Appreciate of your guidence on this matter.
Regards
September 15th, 2007 at 11:35 am eHerman,
If one of the lamps is bad, faulty inverter ic, leaky ballast capacitor, high voltage breakdown when under load would cause display go off after few seconds. If you have a scope i suggest that you place the probe at the output of the inverter ic. It should have a pulse wave form but again, if any components breakdown (defective lamps etc)will send a feedback to inverter ic and shutdown the generator (no pulse output). Try swapping the connector of the 4 lamps ie; left to right and right to left. If it still shutdown i guess you have to confirm it wiht a known good lamp or disassemble the casing and see the lamps for any bad condition or not.
February 25th, 2008 at 1:24 am eDell E151Fpb Monitor Problem
Jestine:
I read your repair article on this monitor. Since my symptoms are not the same, I thought I’d send the description. By the way, your repair book is great!
When monitor is in “sleep” mode (amber power light), moving mouse normally causes monitor to power up and power light changes to green.
Now when I move the mouse, the power light starts flashing green and the monitor screen briefly flashes with the power light. The monitor screen is black when the power light flashes off. The flashing power light is unresponsive to the power button. The first time this happened I was able to reset the monitor by unplugging the power cord. The second time it happened I had to unplug and replug the power cord several times to wake the monitor up.
Thanks,
Kirk
March 2nd, 2008 at 11:02 pm ecan you inform me… when you want to do another course anything about electronic… i would like to join. please.
July 29th, 2008 at 4:31 pm eI have got one of the most advance equipment for Electronic repair.
This equipment can draw out the schematic diagram even without it.
You know anyone interested to invest in these kind of equipment>?
July 29th, 2008 at 9:04 pm eHi Adrian,
Sorry, at the moment no. Anyway i will post your company website into my blog. Thanks!
Jestine
August 3rd, 2008 at 10:02 am eJestine:
Thanks very much spending the time to create the August newsletter. As always, this issue of the newsletter was packed with troubleshooting gems. Thanks for the information and inspiration!
You might want to check out a guy named Steve Litt in the USA. He has written several books on troubleshooting and teaches a course on it also. Although he started in the audio repair business, he now works on computer networks ( I believe). His books and course are based on what he calls the Universal Troubleshooting Process (UTP). The UTP is a process that can be used to troubleshoot virtually any problem. Your writings remind of some Steve’s ideas. I’ve purchased several of his books and definitely recommend them. Give his stuff a look.
Kirk
August 3rd, 2008 at 11:03 am eHi Kirk,
Thanks for the info and i will post the info for my readers to check it out too. Take care and have a blessed day ahead of you.
Jestine
September 12th, 2008 at 6:15 am eGreetings,
I hope you can help narrow down a problem I am having with my Samsung Syncmaster 950p.
For that last few months its been struggling to produce a picture when manually turned on.. I could hear the relay click on, the picture start to come up, then it would collapse, show the amber light, then click again and the picture would show up.
Now it seems to be on its last legs, as the last few times I have tried to start it it has gone through a repeated cycle of clicking on and off… to where it now sounds like a turn signal switch. After a minute or so it does produce a picture, but I feel its just a matter of time before it packs it in entirely.
From my limited experience with electronics, I would suspect a large power cap is failing…. Can you give me any more insight into what I may be facing, and possibly any part number for replacement parts?
thanx.
Mike
September 12th, 2008 at 10:54 pm eHi Mike,
This model have two common fault so far. The first one is the big filter cap problem and the second one is the voltage regulator LM7805 have intermittent problem. Check also all e-caps in the power supply unit. hope this helps!
Jestine
October 7th, 2008 at 1:07 am eJestine:
It’s always a pleasure to read your monthly newsletter and blog. Thanks for bringing the human side to the repair business!
I have a question about the zener diode tester design. Could I substitute four 9V batteries in series for the entire power supply? Since the tester is used for short amounts of time, the batteries should last quite a while. I realize the batteries would put out 36VDC versus 32VDC (after rectifier) but would that be a problem? Batteries would simplify construction by eliminating high voltage wiring, the transformer, bridge rectifier and filter cap.
Thanks,
Kirk
October 7th, 2008 at 11:21 am eHi Kirk,
The maximum voltage the LM317T IC could withstand is 37 Volt and it is safe when the input is 36 volt. However you may have to change the panel meter to 40 or 50 vdc range otherwise the 36 volt would cause the 30 vdc panel meter pointer to kick to max which is very bad to the panel meter. If you take a 50 vdc panel meter then when you want to measure low voltage zener diode , it may be hard for you to see the small scale as you do not know whether it is 2.4 volt or 2.8 volt (assuming you are checking on the 2.4 volt zener diode).
I suggest that you use three 9 volts battery instead of four. If your intention to use the meter for a short while yes, you can put in the batteries instead of transformer and the bridge rectifier plus the e-cap. The batteries current may drain off fast due to the usage from the big panel meter. If can, you may use a smaller panel meter, eliminate the LED to save some current.
October 8th, 2008 at 7:08 pm eHi,
I’ve been reading your blog and found it very useful and interesting! I’m just starting out in LCD tv repair, not professionally at first, but trying to develop it as a hobby!
I’m working on a Logik LOG32LW782 (chassis 17MB22-2) and have made some repairs, however have come across a major problem having fixed the inverter. I have the dreaded vertical line problem! Having read your view on the single vertical line not being fixable I was wondering whether the same applies to numerous vertical lines. The lines I have are various colours and are grouped together with a combined width of about 5 inches. They are over the right side of the screen and change brightness each time I turn the screen on. Also, sometimes many of them go black (although not off) or white.
Could it be something I could have a go at fixing, or even seek a professional…or do you think it’s a write off?
Thanks very much!
Dan Henderson
October 8th, 2008 at 8:51 pm eHi Dan,
I have seen bad e-caps caused this kind of faults in LCD Monitor (for your info i do not repair LCD TV) and many times it was the LCD panle that have problem. Replacement of the LCD Monitor panel solved the problem. So in your case, make sure all the e-caps are working fine and if the voltages to the LCD controller board seems to be okay then chances is very high the problem lies in the LCD TV panel. Hope this helps!
Jestine
October 8th, 2008 at 11:16 pm eThanks very much for this very quick reply. The advice is very useful.
Dan
October 8th, 2008 at 11:51 pm eYou are welcome!
Jestine
October 19th, 2008 at 3:15 am eHi Jestine,
I have a Dell E173FPC LCD Monitor it’s comes on for a few minutes and goes off with the power light on green with black screen, can u advise me as to what to do.
October 20th, 2008 at 8:16 pm eHi Eric,
Please check the C5707 transistors nearby the high voltage transformer. Check also for dry joints in the high voltage transformer. Sometimes a complete short circuit in the C5707 transistor could also cause the p-channel get (fu9024n or fqu11p06) go shorted too. Hope this helps!
Jestine
November 2nd, 2008 at 3:27 am eMr Yong…Recieved your e-books a few weeks ago and they are great.
Well worth the cost.
I restore old short wave radios and vintage amateur equipment and your testing electronic components guide is one of the first books i have ever seen like this.. Excellent information ..Thanks..
November 2nd, 2008 at 5:33 pm eHi Wes,
Good to hear that and keep up the good works! Thanks for the support of my ebook.
Jestine
December 12th, 2008 at 10:14 am eHi Jestine,
Great website ! Anyway, I was wondering if you know any place in JB that sells electronic components, just like those in Jalan Pasar, KL. Preferably within walking distance from the Malaysian Custom. Thx !
December 12th, 2008 at 10:17 am eHi Jestine,
By the way, is it cheaper to get electronic components from Sim Lim Tower or in JB ?
Keep up the good work ! Cheers and thx for your help !
December 13th, 2008 at 12:05 am eHi Lam,
I’ve never been to JB but i’ve been to sim lim tower and the price is not that really cheap as compare to KL. I’ve been to Bangkok and found that their electronic components price are much cheaper than KL.
Jestine
December 15th, 2008 at 1:17 pm eHi,
Just thought that I share my experience about shopping for electronics components in JB (around the Customs area.
I have walked the furthest to Menara Landmark, and there aren’t any shops selling electronic components stuffs. The closest I came across is a hardware shop which sells soldering kits for RM20 and above. That’s the closest electronic stuff I can find. For those desperate, this shop is located right opposite City Square JB, along the rows where Public Bank is located few hundred meters away.
So I headed to Sim Lim Sq. and bought some stuffs there. I didn;t realise Sim Lim Sq and Tower are two different places. Anyway, the following is what I got and the price for everybody’s reference :
1st shop - Forgot the name, but it’s located at #02-02
Digital Multimeter : $16
Single core wire (3m) : $3.60
Wire stripper : $8
2nd shop : UF Technology #03-69
Soldering iron (comes with a mini stand, mini sponge and a tube of solder) : $15
Test pen : $1.80
3rd shop : Again, forgot the name, but it’s quite hidden on 4th Floor.
Bread board : $5.50 (found same one sold in shop #02-02 at $5.90, but of course, there will be discount)
Cheers !!
December 16th, 2008 at 8:28 pm eThanks Lam for the tips!
Jestine