Instruments/tools needed for TV repair

[budm]

Re: Instruments/tools needed for TV repair

Another thing you should have is the Isolation transformer, do not use your new scope on the Hot side of the circuits withouit having what ever your arfe working on powered by the Isolation transformer! otherwise you will blow up your scope and the bridge rectifiers, and etc. in the hot side of the circuits since your scope probe ground is more likely to be connected to the scope power cord ground prong.

[tibimakai]

Re: Instruments/tools needed for TV repair

OK, I couldn't wait for Ebay. I had to have one, do you know how it is
I have purchased a Fluke 87-5 from Amazon(VIPMART) for $250(!!).
I have called the guy and he confirmed that it's indeed is new and comes with the full manufacturer's warranty.
There is a promotion going on now at Fluke. Here is the link:

I have selected the bag. Hats I'm not wearing, I'm not electrician, so I don't need those magnetic holders and flashlight I have.
I have got the Rigol scope and successfully converted it to a 100MHz scope!
Very easy, just downgrade the firmware, run a tool which changes the model and serial number and upgrade the firmware and it's done.

[tibimakai]

Re: Instruments/tools needed for TV repair

Here is a video about the hack:
http://www.youtube.com/watch?v=LnhXfVYWYXE
There is a forum called eevblog where they talk about this mod.

[tibimakai]

Re: Instruments/tools needed for TV repair

OK, I have purchased the Rigol DS1052E for $314 shipped which soon will be a 100MHz scope

[budm]

Re: Instruments/tools needed for TV repair

You will need it if you want to see: the SMPS output drive is putting out, if the switching transformer is putting out the signal (typical AC meter will not have enough bandwitdth to measure AC in 30k~100KHz), AC ripple at the power supply DC output, Video signal, LVDS, clock signals, etc. I would say yes if you are want to really dig deep into the troubleshooting world. But like I said, play with it at your work place first to get use to how to operate it and what you should see and what the waveform of all kind of signals look like, etc.

[tibimakai]

Re: Instruments/tools needed for TV repair

Thank you budm for your help, but the big question still remains unanswered.
Do I need it?

[budm]

Re: Instruments/tools needed for TV repair

Well, you are already at a good place where you work, they must have both digital and anlog scopes that they use during prototype and troubleshooting. If you ask the tech at lunch time to show how they are being used and how to operate them, that will be the best thing to do since you will have real hands on to learn, you cannot beat that!

[tibimakai]

Re: Instruments/tools needed for TV repair

Here are the specs:
Most likely it will be as a DS1102E(100MHz) after the hack:
http://www.rigolna.com/products/digi...copes/ds1000e/
To you these numbers will tell you more then to me.
First, I need to know if I need it and if you guys are saying that I need it, then I will learn as much as possible about them. I may and up eventually using it at my work place to eventually( I'm working for a spacecraft/robotics company as a mechanical technician, but sometimes I'm putting together PCBs also)

[budm]

Re: Instruments/tools needed for TV repair

You may want to read more about digital scope and find out about the pro and the con of the digital scope since it take a slice of the waveform not all the points of the waveform, so if it does not have real high sampling rate, it will not be able to catch all the fast signal.
It is like digital audio and analog audio. So I would say read up on that. Low price digital scope will not likely to have high sampling rate.

[tibimakai]

Re: Instruments/tools needed for TV repair

Thank you cash.
Can somebody explain to me where it would help me this scope and how often I will have to use it?
I'm just trying to justify the purchase. I wanted to buy something for my birthday which it would be a chip tunning for my VW Rabbit, but now I'm thinking if a scope would be a better buy.
I'm kind of inclining to a Rigol DS1052E scope which I think I can get for around $315 from the manufacturer and there is a hack that can transform it to a 100Mhz scope.

[cashkennedy]

Re: Instruments/tools needed for TV repair

In regards to using / interpreting signals, they are often pretty generic.

Like AC signals should be sine waves if they are natural, or a square wave if they are fake. If you notice huge spikes at the begging of a square wave that might be bad, or if you have chunks missing from a sine wave then your not having enough power vs demand / or bad filtering or something.

DC signals i dont know as much about, but i think they appear as straight lines, and if you have bad caps you will see ripple (voltage changing rapidly for short periods of time).

I think you can also test ic's based on the scope readings show in the data sheets. As well as often your expecting a pulsed signal out of IC's?

[cashkennedy]

Re: Instruments/tools needed for TV repair

An analog scope generally has a CRT screen, which means that there is very little logic necessary, adjusting the knobs just changes the resistance / capacitance and what not of circuit inbetween the probes and the crt's electron gun.

If you remember how a crt works its really simple voltage basically is fed to 2 magnets that aim the beam, so the oscilloscope basically receives voltages and then scales the signal and sends it to the magnets to alter the beam path (thus it draws the path of the incomming voltage)...

A digital scope analyses the incomming signals and then creates a picture to represent them and then sends it to a lcd (or ocassionally a crt) using a tcon to draw it line by line (vs just moving a beam around like a cry).

[tibimakai]

Re: Instruments/tools needed for TV repair

so these signals that I would see on the display how would I know if they a correct or not? They are in the SM?(I confess I haven't paid attention until now)
What is the difference between an analog and a digital scope?

[tom66]

Re: Instruments/tools needed for TV repair

The scope looks very good for me, who doesn't know nothing about these instruments.
Could somebody more experienced let me know if a scope like this would be sufficient to repair TVs?

It's a good entry level oscilloscope and fine for TV repair.

You may want to look at an analog scope for less as you will not always need the digital features, but they can come in useful for analysing certain signals like LVDS found on T-cons.

[tibimakai]

Re: Instruments/tools needed for TV repair

The scope looks very good for me, who doesn't know nothing about these instruments.
Could somebody more experienced let me know if a scope like this would be sufficient to repair TVs?

[ahickman]

Re: Instruments/tools needed for TV repair

If you are looking for a relatively inexpensive oscilloscope that performs reasonably well, take a look at the following:

http://www.saelig.com/PSBEB100/PSSA002.htm

[multimeter]

Re: Instruments/tools needed for TV repair

Main thing about soldering iron, you need 40~60 watts capacity, low wattage will not hold up the heat well when the tip make contact with what you are trying to solder, especially when you try to solder the board with large copper area, it will suck the heat from the iron and you will end up lifting the trace because you will be waiting for the temperature of the tip to recover. I use good old 60Watts WELLER WTCPT. Metcal soldering (I use that at work) will be the one I really want to have but it is real expensive.
DMM, I use Fluke 87. Sencore LC-75 CAP/INDUCTOR tester.
You should also build Isolation transformer, GFI outlet.
These are my tools:
http://s807.photobucket.com/albums/yy352/budm/Tools/

budm..... how many fume extractors do you really need?? huh huh??

[tibimakai]

Re: Instruments/tools needed for TV repair

Anybody would recommend this meter? Or there is a better alternative which is not much more expensive?
http://www.prc68.com/I/ESRmicro.shtml
I have seen somebody(forgot who) that was using this meter.
I have contacted the original owner(Russian) of these meters and he quoted me $75 shipped to the US and I can pay through PayPal.

[tom66]

Re: Instruments/tools needed for TV repair

A decent 20 MHz dual channel analog scope cost me £60, which is about the same price as the DSO Nano. I use that one (as well as "Big Bertha", the 100 MHz HP 54501A) to repair TVs, but they're also useful for understanding electronics a lot. Having an analog only scope is very helpful, because it trains you to understand how to use the controls properly, instead of pressing "Auto Scale" each time.

I do like the Nano, but it is a toy. I wouldn't consider it a serious oscilloscope. It has a single channel, with a bandwidth of 200kHz.

[retiredcaps]

Re: Instruments/tools needed for TV repair

I have two which are not lead free and I'm having difficulty unsoldering bigger capacitors.

If you have a conical tip, the I suggest you get a chisel tip. Something like 1.6mm or 2.4mm for better heat transfer.