Now with all other connectors disconnected from A4A4 on power on
red LED goes on for short blink than protection trigg. again to black.
The yellow tantalum in the middle of the picture doesn't look good.
Or is it just a shadow?
Locally can find only:
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Vellman VM203
PICKit™2 Development Programmer is very versatile.
It features on board sockets for many types of PIC® microcontrollers.
Also provided is an ICSP connector, to program your onboard device.
https://www.velleman.eu/downloads/0/modules/usermanual_vm203.pdf
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On A4A4 ISCP is marked like "PIC PGM PORT J55"
Do you know the layout?
Or you have some tool to clamp on PIC 16F877 directly ?
Do you have any picture how did you manage to read out that PIC
I managed to start the remote Gui on my System!
You need the folowing filesCode: [Select]egclient.jar
JimiProClasses.zip
RemoteGui.jar
xerces.jar
I think it will only work with the OpenJDK Java 6 runtime
You need to change the server and localAddress parameters, the server is the E7495 and localAddress is the IP of your PC.Code: [Select]java -Dserver=10.10.0.101 -DlocalAddress=10.10.0.156 -classpath "egclient-patch.jar:xerces.jar:JimiProClasses.zip:RemoteGui.jar" elgato.gui.MainWindow
Some helpful Key kombinations
CTRL-H = Help
CTRL-L = Local (This one is important!)
F1 to F7 = Menu items on the left side
F9 = Mode Button
1 to 7 = Menu items on the right side
Before you can do anything you have to switch to the local mode on your PC, press CTRL-L to do this.
Member here Wolfgang made nice FET probe which can be of good use during your repair ->
https://electronicprojectsforfun.wordpress.com/2018/08/03/a-homebrew-fet-probe-to-1-5ghz/
This is the block diagram of the RF part for the N1996A, the bigger brother. It could help because they are very similar.
So it turns out that on my unit, the spectrum analyzer, signal generator, and two-port insertion loss features seem to work fine, but the one-port insertion loss and return loss measurements give incorrect results. Since there's no block diagram available, I ended up taking apart and reverse engineering the receiver board, shown below. I don't have much previous RF experience, so corrections/suggestions are welcome!
It seems that this unit is a superheterodyne receiver using double conversion, with the 1st LO at 1.5 - 3 GHz, the 2nd LO at ~3 GHz, and a final IF at ~135 MHz. The unit seems to have two separate receiver bands, one for < 2.7 GHz, and the other for 2.7 - 4 GHz ??. There are 2x 5-bit (<= 31 dBm) digital attenuators on the input path, and a 0 - 90 dBm electronic attenuator on the output, although the module seems capable of up to 130 dbm attenuation.
Since this unit is designed for portable operation, the internal cables are short and the assemblies are all stacked on top of one another, making it difficult to probe the receiver board with the unit running. I ended up removing the connection panel and flipping the receiver board, which gave me access to its top side. Since the spectrum analyzer and signal generator features work independently, I'm guessing that the fault probably lies on the feedback path from the source output on to the input path, which runs from the coupler through some filters and SPDT switches (from D to A on the annotated image). Interestingly enough, some rework seems to have already been performed on the filters on this path, probably by the factory?
Next, I plan to probe this path while operating the unit in return loss mode, but this will be a bit tricky because I only have a 100 MHz scope, and no other spectrum analyzers or high-frequency probes. However, I do have a RTL-SDR and a LimeSDR, so I can probably make do, and just need to compile the software stack on my laptop.
So it turns out that on my unit ... Interestingly enough, some rework seems to have already been performed on the filters on this path, probably by the factory?