DENON AVR REPAIRED

 Is DENON AVR Model X-500 Prone To Fungus Attacks And Rusting

Those of you who have read my previous articles on servicing same model might know the reason for my question. For those who have not, here

I received the same model from a different customer living in my home town with the complaint that it just blinks after switching on, which the customer also knew was a protection mode.

I am only giving the image of the model number plate, to show that it is a different set with a different serial number. I am skipping insertion of other images of inside as it will be a repetition.

After dismantling the whole set and subjecting it to thorough cleaning of every part, I took up the remote control for rectification, as it had rusted battery contact springs:

I had to clean the area thoroughly and literally dig out the rusted broken spring from its groove. After replacing the spring and putting the battery, and also replacing the capacitor on it, the remote did not work, even though I had cleaned all the contacts too using IPA. Then I replaced the crystal, upon which the remote started working very well.

Why did I take up this first? Because, controlling the system through manual mode was very difficult, when sets are dismantled and connected externally for check-up. As the display was dim, I dismantled the front panel and was not surprised to see the condition inside:  

    

I cleaned the board thoroughly using IPA. Removed the display and cleaned the legs carefully, as the pins were very thin and likely to break, and replaced all the electrolytic capacitors on this board. Then when I tested, the display was found very healthy and responded to dim commands.

After providing extension wires and connecting the amplifier board externally like how I did in the case (3) link given above, I applied power and saw the serial bulb lighting up indicating high current drawn. I switched off and discharged the tank capacitors and looked for the trouble maker. When I checked the output transistors of the amplifier one by one, I saw two transistors short in one channel. So, I removed them. Still the short was present. (Short between ground and + rail) Then traced it to its speaker protection relay, which was dead short between one pole and one way! I have never seen a relay shorting like this before in my whole years’ experience!

Replaced the transistors and relay after checking every part in that area for any short or open and reconnected the board externally and applied power. This time there was no problem and it worked well. The probable cause for failure was leaky transistor which might have drawn high current shorting the relay. That’s how we also got a thermal error, as the transistor might have been exceeding the temperature limit. Anyhow, I let the set run for several hours before closing it.

You can have a look at the number of pages printed to study the circuit diagrams for easy trouble shooting and the number of minimum components that were replaced in the set, due to the fact that the customer did not have a large budget for the service. 

Anyhow, I fit the set back and delivered it to the customer, after he saw its full functions at my home.

He was so happy to get the set back to working condition. Mission accomplished with great satisfaction getting added to the collection!

Charger power supply fixed

 

 

 

Makita Charger Repair

 

I got this dead charger from another repair shop in town that was not successful in getting this charger fixed. The guy explained that he opened the device and looked for a fault but somehow he was not able to repair it.

That is a very expensive charger and the guy wanted it repaired as soon as possible.

As you can see there were no bulging capacitors or anything wrong with it when I scanned it with my naked eye.

I powered up the device through a current limiter and the light bulb stayed dim which is an indicator of no short in circuit. I powered it through 220 AC volts and checked for voltage reading at the main capacitor but there was none.

If you look at the photo above you would see a marked area and on the top corner you would also see a dark burnt spot and what confirmed this loose connection is when I powered the device up, I could hear a zap sound coming from that area.

The common sense here is to re solder this spot and get it over with but the moment my solder iron tip touched that part, the connection on that line collapsed on two of these pins.

I used wires to reconnect these two pins (sorry no photo) and soldered them down to the board.

I powered on the device and as expected, the power green light came on flashing and according to the user manual that I found online; is normal and that is a sign that the device is ready to charge the battery when attached to the charger.

The repair was done in less than twenty minutes. I called the guy to come and pick up his device who was really shocked that it did not take long to get this charger fixed.

 

Email: dicksonmuchoki@gmail.com

Phone no: +254718814978 / +254735149318

 

 

 

Obtaining EEprom Bios Firmware For Dead flashed LG GDR8163B DVD-ROM Drive

A few months ago my friend Marco brought me two LG GDR8163B DVD-ROM drives. One still working and the other one he had dead flashed over the Pata/IDE port with a wrong turning out upgrade attempt. With the secondhand bought still working LG drive he hoped I would be able to reflash the now defect first LG drive back to a working DVD-ROM drive. Since using the Pata/IDE afterwards no longer is possible. There is a software Flasher program from Devil’s Claw that apparently was designed to repair those older wrong flashed drives on older computer operating systems. But that will only fail on our defect flashed drives when tried. And that program also should help to first make a backup of the original Firmware that is stored in the drive’s eeprom but that also failed on the still working LG GDR8163B DVD-ROM when tried. And there also exists cross FW flashing software. And everything also depended on which IDE/Pata controller board was used.

What also didn’t help are the LG flasher programs, and other programs, that do not save the old firmware before upgrading the firmware. And those same LG flasher programs killed my friend’s drive to oblivion! Which makes it worse is that the firmware bin file in the LG program that is supposed to program the eeprom over Pata/IDE is packed into the boot flash exe file. And so isn’t available and can’t be used to flash the eeprom on an external used programmer when we desolder that deadflashed eeprom from those defect drives. Although I also tried asking the LG helpdesk for that bin file, they simply couldn’t provide it. And nowhere on the entire internet that correct firmware eeprom bin file was shared!

These drives are much wanted for replacing the original defect Xbox DVD drives with. After some additional changes to the internal drive board it is said that they even work better than the original Thomson Xbox drives do (being more compatible with running most if not all Xbox games)  

Previous photo showed the Panasonic MN103S89FDA processor with the TSOP32 SST39SF020A eeprom on its right in the secondhand bought still working drive. And looking for a datasheet for the MN103S89FDA processor will fail too sadly.

What made it more difficult was that the deadflashed LG drive used another TSOP32 eeprom type MX29F002NB that was larger than the much smaller 8 x 14 mm that was used in the still working drive. And I only was able to read those larger eeproms because I had not yet such a special smaller tsop32 socket to read the SST39SF020A in our good working drive. Luckily I found the right TSOP32 to DIP adapter and it was ordered on Amazon for 30,99 Euro

But Before I bought this adapter that took over a month to arrive, I also had bought a third used (probably one of the last drives still available) LG GDR8163B drive on eBay. Hoping that one would also use the larger MX29F002NB eeprom which I already had a matching TSOP32 to DIP adapter for. Sadly when the drive arrived it had the same smaller 8 x 14mm eeprom on its board. And also my supposedly good TSOP32 to DIL adapter had too wide DIP pin rows to fit in my TL866II or in my GQ4x4 programmers! So I also needed new adapter sockets for these eeproms too! Which I found on Grandado consisting out of a set of below shown 7 adapter sockets for TSOP32/40 and 48 pins 8/16 bits! 

  

I only needed the TSOP32 Base board with the TSOP32/40/48 Top board.

And although the seller said that it was only for the TL866II, this set also worked perfectly on the GQ4x4 programmer too! Reading the TSOP SST39SF020A this way was in fact exactly the same like reading the No Adapter DIP SST39SF020A eeprom type version. (The same resulting parallel pin configuration!)

Next PC screen snapshots proved that reading the good FW containing SST39SF020 eeprom verified okay on both programmers in multiple setup ways! Here first on my GQ4x4 as No Adapter version (which in a way the TSOP32/40/48 Top board inserted on the TSOP32 Base board just is!)

But it also verified fine when read as PLCC32 Adapter board on my GQ4x4 universal programmer. On the GQ4x4 programmer the SST39SF020 chip also verified fine with the saved FW bin file when read as ADP-022 TSOP32-DIP32 adapter board!

Which also was confirmed because both my programmers also checked for the right inserted Chip type name during verifying the inserted chip! Next screencopies also show that the TSOP32 Top to DIP Base board also worked fine on the TL866II.

And of course I already was sure that the saved firmware bin file read from the good working third eBay bought LG GDR-8163B drive was correctly read. Because after I flashed the SST39SF020A eeprom in the second drive with it and had placed it back that drive still worked fine afterwards!

Previous screen shots again showed that all TSOP32 chip verify setups worked exactly the same as if  DIP32 SST39SF020A chip was read. And the single (waveshare) 8x14mm TSOP32 to DIP 32 socket worked the same as the 8x20mm Top and Base board adapter did. Making it a DIP32 pin eeprom.

And now that I finally knew for sure that I extracted the right FW bin file from my third eBay bought drive, I still had the first defect drive that needed to be fixed too!

Next photo shows the cover of one of the LG drives. The FW version was the same version 0L23 on all 3 LG Pata/IDE drives.

And my conclusion that all programmer setups resulted in the same good read FW file by using the PC program ANTI-TWIN confirmed that indeed that all saved bin files were identical, no matter what socket setup was chosen! So the TSOP32 Top and Base boards plus the 8x14mm adapter socket made in fact in all setups just a DIP chip pin configuration from my original TSOP32 SST39SF020A chip

Next screen copy shows the adapter setup screen on my TL866II when the same Top and Base TSOP32 to DIP adapter boards were used. Here the third LG drive eeprom was successfully read and verified! Followed by a photo after the eeprom was soldered back into the eBay LG drive. 

 

When I use my hot air station to desolder or solder back components, I use Kapton tape to protect the

 other parts from overheating and from floating from their board positions.

On next photo it shows the soldered back 8 x 20mm MX29F002NB TSOP32 eeprom after it was successfully flashed and verified with the firmware file extracted from the SST39SF020A eeprom. 

Previous screen copy showed the successfully flashed MX29F020NB eeprom on my GQ4x4 programmer. Again the TL866II TSOP32 Top and Base to DIP boards was used without any problem!

Conclusion: Sadly the manufacturers do not leave us any choice when we want to fix our dead flashed DVD-ROM devices. By their evil crippling software resulting in useless devices from useless upgrading software! And sadly only after finding a still good working DVD-ROM Player we can try to

extract the necessary Bin file. Afterwards only desoldering the corrupted eeprom, and re-flashing the corrupted chip externally on a universal programmer is the only way!

Sadly the first defect drive with the MX29F002NB eeprom didn’t work with the from the SST39SF020A copied eeprom file. Reason why is unsolved. 12V, 5V (also feeding the eeprom), and 3.3V voltages were measured fine, and all eeprom pin connections to the Panasonic MN103S89FDA cpu checked out fine too! Maybe the MX29F002NB uses other firmware? And the other difference with the SST39SF020A eeprom is that the MX29F002NB also has 7 Write protection sectors which the SST eeprom lacks.

I also wrote down how the eeprom is connected to the large Panasonic cpu in these drives. Because it was the only way to check if all eeprom pins were correctly connected after it was soldered back.

Below picture shows how all TSOP32 eeprom pins are connected to the Panasonic cpu/controller.

Luckily I didn’t destroy the 2 afterwards still perfectly working LG GDR8162B drives. And the still defect drive maybe already suffered from other issues because the turn table motor also made some sound from its internal rolling ball bearing balls. And the rather expensive ordered eeprom adapter sockets (The 7 Board adapter set was about 70 Euro, and the special 8x14mm TSOP32 socket adapter was about 31 Euro!) surely will come in handy a next time my programmers are needed to extract firmware again!

Anyway I now have a tested working Bin file for all the LG GDR 8163B DVD-ROM drives (B stands for the black front plate) that was very hard to get and most LG DVD-ROM users that also dead flashed their LG drives probably also never had! And this bin file couldn’t be found anywhere on the entire internet!

A Laptop Powering On But With No Backlight successfully  Repaired

 

 

 

 

 

 

 

A university student who needed this laptop urgently brought it to my shop for repair and the main problem was no back light on the screen.

A very simple way to identify a back light issue is to shine a light over the screen and you will see what is being displayed.

I know the photo is out of focus but if you look carefully into it you would see a dim logo of the laptop being displayed.

There could be many reasons for dim display; it could be a bad screen, bad back light board or could be the screen socket on the board itself.

In my case was the main screen connector on board because when I touched the screen flex cable a brief flash of light appeared and then disappeared which could be a bad flex cable or the socket itself.

When checked through my microscope I found a lot of cold and bad soldering joints on that socket and that require a micro soldering job. I got the flux tube out and with a temperature of 400 and air flow of 60 set on my heat station I started gently to heat up the connected after adding the flux on it. To make sure all the soldering joints are connected firmly on board, I touched the socket pins with my flat soldering tip after adding good amount of flux and when the job was done, I let it cool down, clean it with IPA and assembled the screen and hoped for the best.

The screen is alive again but I could see another problem with it but all was well after clicking the restart my PC option and it came on nice and neat.

The customer was happy when I informed him of the repair and he rushed to pick it up because on that laptop he had a lot of information that has to do with his graduation thesis. I was glad I could help out in his matter and to that I could say... conclusion : if I were to found all the connection ok then I could trace the led driver output voltage and also the backlight condition .