Is there any hope

[Jimmckeown]

I zapped my ER9X with FrSky osd (Gruvin version 1) and the DHT diy, when I was soldering a ground wire to the ffd_lite to the 12th pin from the left side of the back pcb. At the same time I had the DHT connected Rxd = GND and Txd = 5v. = spark and magic smoke. Very bright. Much earlier I had removed the shrink wrap from my DHT and found it would fit closer to the case if I turned the module around then forgot I did. Now when I connect the ER9X to the the PC via USBasp I can read the firmware and model information, but with out the HK blue backlight. (I don't remember if it did before) It goes without saying there is no voltage to the main board. I've have replaced the back board that holds the main switch and the small front board that supports the buzzer. The grounding points are continuous. I think the purple wire end was lifted off the pad at least viewing it trough the hot glue it appears so. I'll resolder it but I don't expect it will make a difference. SO! big question is there fix for this problem and do you think the mother board will have to be replaced.

[MikeB]

There's always hope! Actually, if you can read the firmware and EEPROM, It isn't too bad. I'm not certain, but I think you have probably damaged the 5 volt regulator on the main board.

Have a look at http://openrcforums.com/wiki/index.php/ ... rick_-_Fix for details regarding replacing the regulator.

Mike.

[JEANALTAYR]

to avoid this mistake its possible to solder on NEGATIVE line( RUE 250 -POLY SWITCH) avoiding ground line and batt cell short circuit
Hope this help JMI

[Jimmckeown]

There's always hope! Actually, if you can read the firmware and EEPROM, It isn't too bad. I'm not certain, but I think you have probably damaged the 5 volt regulator on the main board.

Have a look at http://openrcforums.com/wiki/index.php/ ... rick_-_Fix for details regarding replacing the regulator.

Mike.

I have pinged the IC1, IC2 and P1 to P4. The continuity for the most part is the same as spare board that I have. The +5v, +UB and GND continue through ICs to the pins in the sockets. The 3v3 circuit appears to be ok as well. I've replaced the switch and buzzer boards. My knowledge of electronics is limited to changing fuses and rewiring bulge pumps and trailer signal lights. I feel that the DHT has been damaged by the +5 voltage. The battery power at the time was around 11.9 volts at the +5v pin at the bottom of the back board and connected to the ffd_lite rev2 and crossed wired to the DHT via one of Rx or Tx pins. Have you any other ideas. I'm running Gruvin's ER9X for FrSky without speakers. I have the D8R-II receiver, hub and sensors.

This brings a question to mind, can the information from the sensors be also used in programming servo movement or is it limited to haptic functions. We a need a strobe to flash when certain sensors or alarm limits warrant landing the plane. Anyway different subject, gotta get me plane in air first.

[MikeB]

Did you check the 5V regulator for correct operation? If you turn the Tx on, then measure the voltage on the three pins of the regulatior, one should be battery voltage, one ground and the third 5 volts.

I may be getting confused with the hardware and software you are using. Er9x is one of the custom firmwares you may load into the stock 9X board. Gruvin hardware and firmware are different from the stock main board and er9x.
So which hardwre main board are you using?
Which custom firmware are you using?

On the stock board, with the latest er9x, many of the sensor signals are available as inputs to custom switches. Form these, you may then control channel outputs, or generate audible alarms on the Tx.

Mike.

[Jimmckeown]

Checked it again with a battery on and there is no voltage on the main board. There is 12v at external power pin at P2. The board is FS-TH9-MAIN v14. The FW is ER9X-r760, ver. V1-5643 erez; Mod= FrSky NT. The software is eepe (AVRdude) on Window 7 64 home premium. Looks like you heat the voltage regulators until the solder melts and change them out. I'm going to use ICs from another board. Some sage advice would be appreciated. Jim

[MikeB]

OK, just check pin 3 of the 6 way connector, with the power switch ON, you should get the battery voltage, then check each of the three pins of the voltage regulator marked 78L05, one pin should be the battery voltage, one ground and one +5V. If you do get the battery voltage, but not the 5V then it needs to be replaced.

To remove the regulator, use some new solder, and deliberately short the 3 pins together with a blob of solder. Also add some solder to the larger tab on the other side. Now keep heating the solder on both sides so all 4 connections melt, and the device comes off, you can try lifting it with a pin. The extra solder allows you to unsolder all three pins at once, and also provides a heat reservoir so one side stays melted while you heat the other (of course, if you have two soldering irons and three hands this is easier!). Use the 'old' 60/40 solder if you have some, it melts at a lower temperature.

Once the device is removed, clean off all the excess solder using solder wick (or stranded wire if you don't have any solder wick) to soak the solder up.
Then solder in the replacement device. It is a standard 78L05 device.

Mike.

[Jimmckeown]

I changed the 78L05 and checked the voltage. No one home. I don't think I checked the 12v side before I replaced it (78L05). On the other hand the replacement took a beating from the desoldering required to remove it from another board. You can't read the jc/78L05 inscription on the voltage regulator. I wasn't able to acquire the 60/40 solder you suggested. Can you think of any other avenues that I can explore? Is there someone that you know that can repair my board. I would gladly pay for the time it takes.

[jhsa]

I'm sure there are people that gladly help you but you have to let us know where you are.. maybe someone live not so faraway from you and can help you..

[MikeB]

So do you have 12V on the right most pin of the replacement 78L05? but not 5V on the left most pin?
Ifno 12V on the right pin, then check for continuity between this pin and 'pin 3' of the 6 way connector. The 6 way connector is to the right on the LCD connector, and the pins are numbered starting from the right. Pin 3 is where the 12V comes into the board from the power switch.

Mike.

[Jimmckeown]

I'm sure there are people that gladly help you but you have to let us know where you are.. maybe someone live not so faraway from you and can help you..

I live in Parksville, located on Vancouver Island British Columbia, Canada. Phone number is 1 or 01-250-951-0021

thanks Jim

[Jimmckeown]

So do you have 12V on the right most pin of the replacement 78L05? but not 5V on the left most pin?
Ifno 12V on the right pin, then check for continuity between this pin and 'pin 3' of the 6 way connector. The 6 way connector is to the right on the LCD connector, and the pins are numbered starting from the right. Pin 3 is where the 12V comes into the board from the power switch.

Mike.

I don't have 12v power at the either the 78L05 or the 6 way connector. Back to you my friend.
Jim

[jhsa]

hhmm, sometime ago, if I remember correctly, someone fixed his board and after replacing the regulators still didn't have battery power on the 5V one.. the problem was a burnt trace near the LCD plug I think.. I'm going to try to find the thread..

EDIT: Found it. Maybe this helps

http://openrcforums.com/wiki/index.php/ ... rick_-_Fix

[MikeB]

OK, lets go back to the beginning of the battery supply, The battery connects to the board in the back on the Tx. The +12V (nominal) is the centre pin of the three way connector. Start there, and check for battery voltage at that pin. From there, it goes to pin 3 of a 12 way connector, check the battery voltage gets there, if not look to see if the copper trace on this board is burnt. If it gets to pin 3 of the 12 way, check the pin 3 on the 12 way on the main board. From there, it then goes to pin 2 of the 6 way on the main board. From there, it goes off to the power switch, and comes back on pin 3 of the 6 way connector.

Mike.

[Jimmckeown]

hhmm, sometime ago, if I remember correctly, someone fixed his board and after replacing the regulators still didn't have battery power on the 5V one.. the problem was a burnt trace near the LCD plug I think.. I'm going to try to find the thread..

EDIT: Found it. Maybe this helps

http://openrcforums.com/wiki/index.php/ ... rick_-_Fix

Right on jhsa, this is exactly the same location. Big Thanks. Jim

[Jimmckeown]

OK, lets go back to the beginning of the battery supply, The battery connects to the board in the back on the Tx. The +12V (nominal) is the centre pin of the three way connector. Start there, and check for battery voltage at that pin. From there, it goes to pin 3 of a 12 way connector, check the battery voltage gets there, if not look to see if the copper trace on this board is burnt. If it gets to pin 3 of the 12 way, check the pin 3 on the 12 way on the main board. From there, it then goes to pin 2 of the 6 way on the main board. From there, it goes off to the power switch, and comes back on pin 3 of the 6 way connector.

Mike.

Yes the copper trace is burnt but only evident by a mm size piece of wire protruding nearly vertical beside the 12 way socket. I'm so pleased thanks Mike
Jim

[jhsa]

I wonder how healthy the regulators are...

[MikeB]

Probably OK, and one has been replaced anyway. The original problem probably shorted the battery through the (now) burnt trace.

Mike.

[jhsa]

Ah ok!! didn't realise that one of the regs was already replaced.. I do apologise..
then it's time to Rock'n'Roll..
and have a beer

[Jimmckeown]

I'm sure there are people that gladly help you but you have to let us know where you are.. maybe someone live not so faraway from you and can help you..

Parksville, Vancouver Island BC Canada
[email protected]
250-951-0021

[Jimmckeown]

I don't know where my message went, so I'll start again. When I replaced the voltage regulator and jumper wire and connected the battery the DHT binding light started to flash and when I turned the TX on the screen logo and model name appeared. However when I switched it off the backlight and DHT stayed on. I checked the voltage and 5 v +/- at all the right locations. After removing and replacing the battery the logo didn't appear. In the process of checking it out I touched gnd at the 78L05 and the input side. Small spark and trace smoke. I've gone around the area of the regulator and discovered that there are 2 small resistors? missing. They are in between the 12 point connector and LCD ribbon connector. They could be R4 and R5. Above the row of transistors numbered C2to C10 there are 2 transistors, possibly R1 and R2 with 000 code markings that are interconnected according to the circuit tester. They are in circuits are 28 and 29 of 30 pin LCD ribbon cable connector. On the back of the main board there is an exposed copper wire that is located immediately below the small trace wire that burnt out in the last fiasco subsequently replaced by the jumper wire. I'm more than little depressed with the outcome to date. But I'm willing to give it another try. I would like to know the name and the component that I'm referring to as R1 R2, R3 and R4 that I note go to NC and 0R. One thing I forgot to mention is the input side of the VR part of the pin was burnt off. I'm assuming the input is on the right side facing toward the LCD cable. According to the schematic for IC2 I have this backwords. I must have metered 12v at this location once before. Can you get me off on the right foot again.

[MikeB]

Can you post acouple of pictures of your board? (Front and back). My 'spare' board is a V1 and doesn't have any component labelling on it, so I don't know where the components you refer to actually are. My board does have two components missing between the 12 way and the LCD connectors.

Mike.

[Jimmckeown]

2012-06-03_180843.jpg (35.31 KiB) Viewed 14005 times

9X_Main_2_Brd.pdf

(150.46 KiB) Downloaded 209 times

Here are the schematics that I used. The board that I have is V 1.4 not V2 The back of the main shows the replaced jumper and the exposed copper trace ~15 x 1.2 mm. It is continuous along this length. I'm inclined to expose it further. Oh I should mention the circuity is covered by the adhesive left behind when the LCD sponge protection is removed. Could clean it with acetone if there is reason to. Apologise for the photograph resolution not suited to the camera I was using. Again thanks for your support. The 9x_Main_2_Brd.pdf originates at 9x forums.

Jim

[Jimmckeown]

The R1 and R2 at the top of the picture should read R4 and R5. Jim

[ReSt]

Jim,
have a look here. It shows the main power distributions

http://www.rcgroups.com/forums/attachme ... id=4445394
http://www.rcgroups.com/forums/attachme ... id=3933787
http://www.rcgroups.com/forums/attachme ... id=3933786
http://www.rcgroups.com/forums/showpost ... count=6779

Reinhard

[MikeB]

Did you post a picture of the back of your board? There isn't one in your post.

When you say VR pin burnt off, is this still burnt off? or did you replace it and it is now complete?

Mike.

[Jimmckeown]

Yes I ordered 4 replacements yesterday, so rather than lifting another off an existing board I'll use a new one. Jim

[Jimmckeown]

I Soldered in a new vr an AP1117Y5 from Digi-tech which is supposed be the same as the 78L05. At the same time I replaced the DHT. The result I had a blue screen but no logo. The binding signal flashed on the DHT DIY. Before that I changed the battery to 8v and went about checking with the voltmeter at the various locations that were supposed to be either 8v or 5v or 3.3v. They were ok but I mindlessly contacted the 3 pins under which the battery power is sourced. Well, you have voltage in the centre with a ground on each side. The buzzer in the DHT went off for a few minutes and quit. The attached photo shows the previous damage. On inspection vr gnd is maybe a trace different. Only the battery voltage is present.

[MikeB]

I have a suspicion the pinout of the AP1117 is different from a 78L05. Need t check the datasheets.

Mike.

[Jimmckeown]

I have a suspicion the pinout of the AP1117 is different from a 78L05. Need t check the datasheets.

Mike.

Should be Digi-key.