$20 LCR ESR Transistor checker project

[stj]

Apology for the noob 1st post but I am a little confused on which fleabay item to purchased and which FW is to be used 

I am looking for mainly an "in circuit ESR meter" to check caps on a GPU graphics card so am wondering what is the best method or unit to build or buy since there are a number of ESR options

firstly, you cant do in-circuit testing.
that's a myth from the days of CRT tv's when caps where not used in parallel with each other.

as for the best tester, i would say it's the TFT colour kit at the moment - unless you want one that's built.

[KD0CAC John]

Not that I know , but thought [ without trying ] that depending on in circuit , series / parallel , math is used , same as like batteries in series add voltage , in parallel add current ?

[stj]

no.

lets say you have 3 caps in parallel.
if you multiply the esr by 3, you are assuming they are all the same.
when one may be bad.

[KD0CAC John]

Well again just basic math , if the math and the value marked on caps do not match , then looking at caps individually ?

[retrolefty]

no.

lets say you have 3 caps in parallel.
if you multiply the esr by 3, you are assuming they are all the same.
when one may be bad.

 You mean divide by 3, they are in parallel.

[stj]

no.

lets say you have 3 caps in parallel.
if you multiply the esr by 3, you are assuming they are all the same.
when one may be bad.

 You mean divide by 3, they are in parallel.

no, i mean lift them and test them individually. 

[bitseeker]

I am looking for mainly an "in circuit ESR meter" to check caps on a GPU graphics card so am wondering what is the best method or unit to build or buy since there are a number of ESR options

Although in-circuit testing can be done, depending on the circuit layout, doing so may only be a hint that something may be incorrect, which will have to be followed up with out-of-circuit testing of individual components. However, in-circuit testing could just as well yield completely erroneous or misleading results, requiring out-of-circuit testing.

Regardless of the equipment, you need to know the circuit layout and the implications of how and what you're testing. For best results (and fewer headaches), test components out of circuit.

[upsss]

no.

lets say you have 3 caps in parallel.
if you multiply the esr by 3, you are assuming they are all the same.
when one may be bad.

 You mean divide by 3, they are in parallel.

no, i mean lift them and test them individually. 

No, he really meant MULTIPLY the ESR by 3.  If you want to know the capacitance of each capacitor, assuming they are all identical then you would divide the total capacitance by 3.

If you have 3 identical capacitor in parallel with identical ESR, the ESR of one capacitor would be 3 times the parallel ESR (again assuming all 3 ESR are identical).  If you have 3 capacitors in parallel and one of them is bad (its ESR is high) then you cannot tell from the parallel ESR that you have a bad capacitor.  That is why you need to test each capacitor individually, out of circuit!

[stj]

in reality it's more common to find an electrolytic with a ceramic in parallel with it.

[upsss]

If it is only one electrolytic in parallel with a ceramic (assuming the ceramic is not bad) then the measured ESR would be mostly the ESR of the electrolytic since the ESR of the ceramic would be at least an order of magnitude higher than a good electrolytic.

[TheBay]

in reality it's more common to find an electrolytic with a ceramic in parallel with it.

Linear power supplies, audio amplifiers etc have electrolytics in parallel.

[Monroe]

So far I really like this little tester and it was worth the effort.

I have a question OT: I have a LeCroy 9400A that I would like to upgrade to the FFT option however I do not have and do not want to buy a eprom burner for a 7256 eprom. I have 6 eproms that need to be burned if someone has a burner and would be willing to help me out?

Monroe

[Kosti]

Hi All

Thanks for the reply people

Apology again can someone please point / link to me which unit [TFT colour kit] that was mentioned? I',m happy to build it and add this to my arsenal of tools to figure out this GPU issue however its impossible to obtain the schematic, but I suspect something is causing the GPU not to post to display, I could try the "other" myth of baking it but for now happy to try my hand in trying to check a few caps /trans etc see if this leads me to the defect. If it ends up being the GPU MPU itself so being it.

I was going to try and build the CRO method of adding in a 100khz signal but my freq gen is somewhere in storage and hasn't been used in like 20 years! I'm trying to get back into some basic fault finding and hope I can have a crack and resurrecting this paper weight

A link to the latest Kit and FW I should grab from ebay or another source would be appreciated chaps,
PEACE
Kosti

[Willem52]

For example, the here so called 'AY-AT' color kit:
http://www.aliexpress.com/item/2016-DIY-kits-TFT-LCD-M328-Transistor-Tester-LCR-Diode-Capacitance-ESR-voltage-meter-PWM-Square/32649811953.html?spm=2114.13010608.0.56.J7yA7x

AY-AT - K firmware: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=249731

AY-AT - M firmware: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=252428

Instructions attachments

[Pukker]

For example, the here so called 'AY-AT' color kit:
http://www.aliexpress.com/item/2016-DIY-kits-TFT-LCD-M328-Transistor-Tester-LCR-Diode-Capacitance-ESR-voltage-meter-PWM-Square/32649811953.html?spm=2114.13010608.0.56.J7yA7x

AY-AT - K firmware: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=249731

AY-AT - M firmware: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=252428

Instructions attachments

Hi Willem52

What are the fuse settings for the M firmware?

Thanks

[Kosti]

For example, the here so called 'AY-AT' color kit:
http://www.aliexpress.com/item/2016-DIY-kits-TFT-LCD-M328-Transistor-Tester-LCR-Diode-Capacitance-ESR-voltage-meter-PWM-Square/32649811953.html?spm=2114.13010608.0.56.J7yA7x

AY-AT - K firmware: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=249731

AY-AT - M firmware: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=252428

Instructions attachments

Thanks for taking the time to link these, I will look at grabbing one of them

Is this one the same of different since I don't use Aliexpress I found this one on ebay

http://www.ebay.com.au/itm/GM328A-LCD-Transistor-Tester-Diode-LCR-ESR-Meter-PWM-Square-Wave-Generator-M3M3-/311674321737?hash=item48913cbb49:g:sjgAAOSwCGVX3NDJ

As for protection do you need to add in some diodes in the event some caps may still have charge?

PEACE
Kosti

[madires]

What are the fuse settings for the M firmware?

The same like for the k-firmware: -U hfuse:w:0xd9:m -U efuse:w:0xfc:m -U lfuse:w:0xf7:m

[Willem52]

Is this one the same of different since I don't use Aliexpress I found this one on ebay

http://www.ebay.com.au/itm/GM328A-LCD-Transistor-Tester-Diode-LCR-ESR-Meter-PWM-Square-Wave-Generator-M3M3-/311674321737?hash=item48913cbb49:g:sjgAAOSwCGVX3NDJ

As for protection do you need to add in some diodes in the event some caps may still have charge?

PEACE
Kosti

I think these are a clone of a clone. In this case a ready built one with SMD components.
This one has also the protection components like the 'AY-AT' does.

[stj]

it's also mislabeled "GM328A"
that guy needs his ass kicked hard, someone is going to re-flash it with the wrong firmware because of that - i just know it!

btw, DONT BUY IT.
look at the 10k resistor to the left of the encoder!!!!

[stj]

this is the original.
http://www.ebay.com.au/itm/182221397168

and a case!
http://www.ebay.com.au/itm/112108340467

[TheBay]

it's also mislabeled "GM328A"
that guy needs his ass kicked hard, someone is going to re-flash it with the wrong firmware because of that - i just know it!

btw, DONT BUY IT.
look at the 10k resistor to the left of the encoder!!!!

That 10k resistor is priceless! 

[NiklasO]

Thought i'd open my MK-328 and put some pictures up.

Differences with mine are, Green PCB but seems decent quality, no EZM Studios logo on the casing or inside, but exactly the same PCB layout and components.
Ignore the hot snot on the terminals, I put that there.

About to fit a 16mhz Crystal and debating fitting a rotary encoder...

I got the same one. You don't happen to have the latest m-firmware compiled (or the Makefile for m?) for this one or could someone compile it for me (8Mhz)? Thanks!

[TheBay]

Thought i'd open my MK-328 and put some pictures up.

Differences with mine are, Green PCB but seems decent quality, no EZM Studios logo on the casing or inside, but exactly the same PCB layout and components.
Ignore the hot snot on the terminals, I put that there.

About to fit a 16mhz Crystal and debating fitting a rotary encoder...

I got the same one. You don't happen to have the latest m-firmware compiled (or the Makefile for m?) for this one or could someone compile it for me (8Mhz)? Thanks!

I still haven't flashed mine as I'm trying to find the original firmware just in case I want to go back to it, either MK-328 or GM328 Firmware.

Does yours also not say EZM Electronic Studio? I think these may just be later versions as I looked at all the pictures of the ones sold on Banggood and none say EZM Electronic Studio on the customer review images.

Also the red boards were dated 2014.

[NiklasO]

Thought i'd open my MK-328 and put some pictures up.

Differences with mine are, Green PCB but seems decent quality, no EZM Studios logo on the casing or inside, but exactly the same PCB layout and components.
Ignore the hot snot on the terminals, I put that there.

About to fit a 16mhz Crystal and debating fitting a rotary encoder...

I got the same one. You don't happen to have the latest m-firmware compiled (or the Makefile for m?) for this one or could someone compile it for me (8Mhz)? Thanks!

I still haven't flashed mine as I'm trying to find the original firmware just in case I want to go back to it, either MK-328 or GM328 Firmware.

Does yours also not say EZM Electronic Studio? I think these may just be later versions as I looked at all the pictures of the ones sold on Banggood and none say EZM Electronic Studio on the customer review images.

Also the red boards were dated 2014.

I have no EZM on board or case. Mine looks exactly like yours.

[flywheelz]

I still haven't flashed mine as I'm trying to find the original firmware just in case I want to go back to it, either MK-328 or GM328 Firmware.

The Chinese are not relenting to give up the original firmware and they usually lock the chips  .  Have you tried contacting the seller, maybe offer exchange for a positive feedback?  In any case take pics of the "Menu" to see what they enabled so you can recreate later. 

The most refined and reliable firmware is the "k".   The automatic Capacitor test on pins 1 and 3 as great when you got a batch of caps to test.   I think most testers are based on "k".  On the other hand, the "m" is speedy, flashy, with extra features but might need some tweaking.

Above statement is my opinion.