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About Shorted Resistor
By Jestine Yong on September 15, 2009
Shorted transistors, diodes, capacitors, transformer primary winding and etc are quite common but have you ever come across a shorted resistor before? As for me, so far i have not seen any yet. Usually a resistor will go open circuit or the value of the resistance will be increased to higher ohm. Shorted resistor means the value that you check on the resistor would show ZERO ohm regardless whatever the color code (value) printed on it. If you have come across one, i would like to hear from you-thanks!
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jgmanza
September 16, 2009 at 5:46 am
Hello Jestine, I am currently working on a Daewoo CRT TV, and it has a lot of 5 color resistors. From your testing electronics book I bought I learned to read 5 color resistors. But I am having trouble with some. What is the value of resistor brown-green-orange-gold-green? I thought it was 15.3 ohm but I am not sure because it reads about 200 ohms when I test out of circuit.
By the way I have repaired 6 CRT already, and I wish God's blessings on you and what you are doing.
Thanks So Much.
beh
September 16, 2009 at 1:54 pm
HELLO JESTINE
according my experince :
1- only the resitors with small value blow(getting open) like 1 ohm 1/4 watt
or 1 ohm 1/2 watt or 10 ohm 1/2 , 1/4 watt some times the bigger one like 100 ohms .the bigger than 100 ohm just changeing the value and make problem
2- in older tv/radios set the manufatures used small value resistors as fuse or use fuseble resistors in circuit
3- oldre sets the resistores also used as voltage divider some time
is power supply they have very big watt and not to much ohmic value
but very big budy
beh
admin
September 16, 2009 at 8:00 pm
HI Beh,
Thanks for sharing!
Jestine
admin
September 17, 2009 at 7:40 am
HI Jgmanza,
From the 5 color band resistor calculator, yes the value is 15.3 ohm:
http://samengstrom.com/nxl/10116/5_band_resistor_color_code_page.en.html
By the way is the Daewoo CRT TV problem solved after replace it with 15.3 ohm resistor?
Jestine
jgmanza
September 18, 2009 at 4:41 am
Thanks Jestine,
I haven't replaced as yet. This is because I there are about 9 resistors that end with the last two colors of : gold - green. But on the the online calculators for 5 bands, they don't allow me to enter the green for tolerance value. Also I have to order this type of 5 band with the color that ends in green.
However I can now proceed as I was calculating it correctly.
I have one other unrelated question, I have started to test voltages on TV and most of the problems are power supply. How can test voltage on a mosfet. Do I put the probe to drain and source?
I will buy the LCD Monitor repair manual this week, as I understand it has more on how to test voltages. I learned a lot from the last article you wrote. Thanks. Its a pity that we cannot do a small monthly donation online here. Its one way how we show our appreciation.
Thanks
Jorge
admin
September 19, 2009 at 6:27 pm
Hi Jorge,
You can test the voltage on the drain and source pin and i prefer to test it with scope which is more precise. By getting my ebook is good enough to support me-thanks. Have a good day!
Jestine
Papo
September 20, 2009 at 4:01 pm
Hello Jestine,
As an electronic repairer I've been one of your fans for nearly 3 years now. I'm so grateful for all the useful repair tips and news letters you have been providing. Through the help of a Malaysian friend (Mr. Anuar) here in Nigeria, I was able to pay for your ebook on Testing Electronic Components last year and got it. I've been so eager to buy the ESR meter and Ring Tester but the only way I can send the money across to you is through him since money laundary regulations in my country makes it difficult to pay online. Unfortunately, he doesn't visit home (Malaysia) too often. So, I have given up on that issue for now.
Currently I have a 10" color TV (Model: Genexxa CTV10) with sound problem. The volume up/down is not functioning. The sound is permanently loud. I changed the sound IC: AN5265. I tested the voltage on pin 4 (vol control) and noticed that it doesn't change. It's 2.5v. I traced back to a 42-pin IC: M34300-012SP. No voltage change on pin 22 of that IC while pressing the volume button. I've also tried getting the datasheet for that M34300-012SP IC from Mitsubishi website but could not find it.
Please, do you have any idea what should be done to solve this volume problem?
Thanks
Papo
rajascientist
September 21, 2009 at 1:43 pm
Hi Yong
Sure I will tell you if I come across such shorted components.
admin
September 24, 2009 at 8:35 pm
Hi Papo,
Thanks for the support!
Jestine
Laya
October 17, 2009 at 12:10 am
Hello Jestine,
I very much appreciate your work in helping people like us in solving common problems with lcd monitors. Already repaired our DVD player and LCD monitor, now working great, following your posting and fine suggestions.
My friend has a ViewSonic Optiquest Q20wb with no power symptom. We replaced fuse and bad caps and now it shows Amber Light instead of Green. I found out a SHORTED RESISTOR with (RED..GREEN..BLACK..SILVER) reading Zero Ohms(used analogue multimeter, least Resistance mode). And came to know that its actually a 25 Ohms with 10+/- tolr. Its located near NEW/REPLACED 22UF 50V capacitor and POWER FET DM07652RB (which I observed that,is not getting/holding any charge when powered up).
I did some browsing and came to know that because of bad Resistors, capacitors cannot hold charge in them and "surge discharge" would happen. I'm a comp engg not an electronics. Sorry for any misunderstandings in the concepts.
I need your suggestion regarding replacement of this resistor as I'm unable to find an exact match (currently available at NJ,US are 10Ohms & 33 Ohms). Also any suggestions testing the POWER FET functioning would be great.
Thanks in Advance!
-Laya
admin
October 19, 2009 at 7:02 pm
Hi Laya,
You can use a 18 ohm in series with a 6.8 ohm resistor and the result would be 24.8 ohm which is very near to 25 ohm. It is acceptable since the original value have a 10 percent tolerance. As for testing the FET, i had compiled the information into an ebook at TestingElectronicComponents.com
Jestine
Don Meadows
December 1, 2009 at 9:10 am
Justine,
I have been an electronic technician (electronic repairer) for 40 years, and have never seen a shorted resistor. If it IS shorted it seems like it would almost have to come from the factory defective.
I wonder what type of resistor it is.
Like you, I see no physical way a resistor can FAIL in a shorted mode.
My Best,
Don Meadows
sreekumar
December 6, 2009 at 11:26 pm
shorted means there is no resistance, then there is no meaning in shorted resistor, i think that is meant for a zero value showing reistor
admin
December 7, 2009 at 9:31 pm
HI Sreekumar,
Yes, showing zero ohm resistance.
Jestine
admin
December 7, 2009 at 9:58 pm
HI Don,
Yes, so far never come across this problem before.
jestine
dan
January 7, 2010 at 2:18 pm
Only Opens! Repaired my dad’s color TV ~1978 while home visiting from college. Told him I’d need the schematic for less than $10 to start, he gave me $20. Inside I found 1 blown up and 1 burned part. Available replacement power resistor was much larger wattage, thermistor was in lots of pieces and unrecognizable. Schematic essential to ID. Resistor mounting required “creativity” but no issue in huge cabinet. Dad had $12 in change & working TV in less than a day. He let me keep the cash as he’d just had it repaired for $100 & 3 week wait. Believe thermistor failed low overheating resistor before disintegrating.
admin
January 8, 2010 at 9:27 am
Hi Dan,
That was a good sharing!
Jestine
Bkeesk
May 3, 2010 at 11:30 pm
Viewsonic Q20WB: Have replaced 6 capacitors,but still blinks on - off every few seconds. What else should be suspect?
Thanks for any help available.
admin
May 4, 2010 at 5:44 am
HI BKEESK,
Is the output voltages from the SMPS good and stable?
Jestine
Gary Nichols
August 13, 2010 at 1:29 am
I have an Optiquest Q20wb that I replaced caps on Power inverter board. Monitor works GREAT. However, it has a tendency now to turn a green hue. If I shut it down and let it sit for a few minutes then turn it back on it will work fine for a short period of time then THE GREEN HUE again. I cannot find anything burnt or shorted on the video control board. I have read 2 other blogs with people who have had the same issue arise with this monitor. Can you give me a clue what it is Jestine? Thanks Gary Nichols
admin
August 13, 2010 at 8:15 am
HI Gary,
I have seen this problem before but it was not in this model. It was caused by the bad LCD panel. The only thing that you can do is to reflow the components in the lcd controller board. Most of the time only through replacement of lcd panel then only the problem can be solved.
Jestine
Almas
March 4, 2012 at 6:43 am
This is very useful website for those who want to repair electronics at home. I need some help in regard power supply of compaq deskpro pentium iii
Almas
March 4, 2012 at 1:33 pm
Can any body help me to test and pinout of compaq 334112 power supply?
Langstain E.Mhango
March 24, 2012 at 4:06 am
the information on resistors is quite touchy.we need more of this from those who have come across problems associated with resistors.gud day.
ABRAHAM CHEMWENO
July 30, 2012 at 6:03 am
i am dealing with a flamingo tv model CTV-1468. I have the power supply working but it is not giving any output on the crt tube
Jestine Yong
July 30, 2012 at 10:09 pm
Hi Abraham,
Is there B+ supply voltage and a pulse to the HOT? Without these two signals, the flyback will not be energized thus no voltages (g1, g2 and even no high voltage.
Jestine
ABRAHAM CHEMWENO
July 30, 2012 at 6:06 am
what is causing the base of a monitor cause a hissing sound
Jestine Yong
July 30, 2012 at 10:05 pm
Hi Abraham,
Hissing sound usually from inductor or transformer. You may need to remove the cover or the base to hear where the sound from.
Jestine