Triumph 4850-95EP not turning ON.

Hello,
It's been almost 2 years since I got my triumph. But starting from last week I don't know what happened. When I turn on the switch, the screen blinks and goes blank. I checked my breaker and everything is fine. Then I found out that F3 (Backgauge overload switch was off) so I turned it back on and a smoke came out from A4 board. It was one of the IC. I can't tell the part number because of the damage.
So my questions is, do I need replace the IC, if you can help me with the part number, or just get a new A4 circuit board?

 

Regards,
Oleg T.
Alonex ICEE Labs

 

Hello Sir,
Thank your for your input. I talk to the technician and they told me to replace the entire kit because they're no longer making this board. But personally i rather change the component but couldn't find info about the component (Input voltage and output voltage/max current of the DC-DC converter ...) is there anyway other way to know that?

 

Dear Yosef,

What do you/they mean the "kit", the entire PC board? And what is its price? May be, it is a solution.

The best way is to observe a such proper card, or the next revision of such card with an exact or similar DC-DC converter IC in a SMD package(I have even seen such picture on this site). The PCBoard should be reverse engineered, at least partially and at least virtually in mind, beginning from better understanding of the PCB's functional purposes, power supply and its output stage. You should find a component level electronics repair lab in your area, if you are not familiar with the basics of electronic circuits design techniques and templates.

Again, looking on your pictures, I expect its digital IC's is supplied with 5VDC (two caps, output of the DC-DC converter), and input voltage (24VDC expected, but should be checked) is on the 470uF/63V. I have referred a few IC's which might be used in this DC-DC converter, the datasheets of the devices should help in better understanding of the actual circuit. The 5VDC bus should be checked for a short circuit, the four output transistors should be checked too.

Regards,
Oleg T.
Alonex ICEE Labs

 

Hello,
I was trying to get with more progress but no luck. The technician want me to replace the board with the keypad. It cost almost $1,370. All the picture that you have seen on this site are V0.2 mine is V2.10.The other thing that i noticed is the board (A4) should get 24V but when i measured it is getting 39V. No luck with the component level electronics repair lab in my area. If maybe please take a look at the diagrams you can tell me what am i missing. Thank you so much.

 

Dear Yosef,

Sorry for delay, just looked on the forum.

Input:
The transformer T2 gives output ~24VAC, so we should have after diode bridge, on the C3 capacitor 24VAC*1.41=33.84VDC (the second picture). You can select an IC with the suffix "HV" (60VDC and not 40VDC input) from a list I have sent you before. Of course you should check for correct pinout of a selected IC (make reverse engineering of this fragment, draw it: basically diode, inductor & capacitors).

Output:
I expect 5VDC (looks as the board of older technology) on the two small caps (output of the DC-DC converter). Please provide nominal voltage of the capacitors, and list all the known IC's on the board . Remove the damaged IC and check its output for a short. You can find data sheets of the listed DC-DC converters in such case with typical schematics.

Output current:
I would supplied 5VDC bus from a Lab Power Supply Unit, and selected an IC with at least 100% reserve.

This job requires basic electronics knowledge and experience. Otherwise, small mistake may cause a damage of the board and/or other components of the machine.

What is the price of such new/used machine? Almost $1,370 looks as proper price for the new board & new KB.

Regards,
Oleg T.
Alonex ICEE Labs

 

Dear Yosef,

I have downloaded your pictures of the board, them have a better resolution.
The board may have additional 5VDC regulator. Let's refer the LM2576, LM2596 by ON-Semi or by NS for now.

1. Check, where is going the left pin of the inductor (positive output), if it is connected to a pin of the microcontroller?
2. Make a pictures of the bottom side ("PS - print side").
3. Remove the green revision label of the uCU and make its picture.
4. Check, what is a value of the inductor, if available any label?
5. Check again the input voltage, 39VDC looks as too high (if 40VDC DC-DC version was used).
6. May you see on the new board and capture the DC-DC converter type, or ask the technician to re-translate it you, even if the converter is not in TO-220 but in a SMD package?

You will need to fix the PCB prints in the area.

Regards,
Oleg T.
Alonex ICEE Labs