Broken Guitar Synthesiser interface

[Larkland]

I've just been given a dud Roland GI-10 Guitar>Midi interface. I'm not an electronics whiz and don't know what I will be able to do with it. There is a blown component, though I'm not sure what it is. Could anyone please tell what the blown component is (there are two very similar ones next to it)? Also, how difficult would it be to swap it for a new one? And how likely is it that changing the blown component will fix the GI10, or will whatever caused the component to blow have caused electrical mayhem in the other components on the board?

Edit: On second thoughts, doesn't Q1, Q2, Q3 indicate transistors?

 

[Nigel Goodwin]

Yes, it's a small surfacemount power transistor, presumably identical to those alongside it.

Replacing it 'may' cure the problem, but the PCB looks to be somewhat damaged by the failure.

 

[Larkland]

Yes, it's a small surfacemount power transistor, presumably identical to those alongside it.

Replacing it 'may' cure the problem, but the PCB looks to be somewhat damaged by the failure.

Thank you. Looking further, I've found a loose component, and a place on the board that it *may* have come from. (See attachment).

If it was a matter of spending a few quid on components and "having a go", then it would be worth it. But if the chance of success was too low, then it'll go in the council electrical recycling bin. Any advice will be greatly appreciated.

 

[Nigel Goodwin]

Looks like D20 is duff as well then.

 

[Larkland]

I had given up on this. But, one of my work colleagues who REALLY knows electronics has said he'll have a look at it when he's back from holiday. And, Roland UK has just sent me a PDF of "service notes" which includes the parts list. Q3, 4, 5 are all 2SA1736, and D20 is a SB20-03P-TD. So, it's not looking nearly as impossible today as it did yesterday.

 

[Larkland]

Could anyone tell me what a MB3782PE-ER Switching Regulator IC can be searched under. Part number 15829405 if that helps. I was utterly gobsmacked to see my colleague debugging the guitar synth interface. He used three regulated power supplies in an electronics lab to produce the three voltages necessary for the board, plugged them in, and the LED lit up and was responsive showing that the microprocessor was working, allowing us to scroll through menus etc. As he's been so generous with his time and expertise, I'd like to do as much as I can re: sourcing the components he recommends be replaced without having to ask him again, but am stymied as to what to get.

What I need is:
SB20-03p-TD diode. The only easy one, available from farnells.com with a minimum order of 1.
SFPB54 diode. Can't immediately find a supplier, but should be substitutable.
MB3782PE-ER, switching regulator IC. This is probably OK he says, but would be worth getting one with the parts order just in case. As above, I can't find info on it.
2SA1736, transisitor, searching for these or equivalents.

Any advice?

 

[OSCAL]

Hi
The MB38782-PE is the main power switching controller (FUJITSU)
DATASHEET :- https://www.alldatasheet.net/datasheet-pdf/pdf/220559/FUJITSU/MB3782.htm
Little information if it helps
REGARDS

 

[OSCAL]

Hi
SB20 30V SCHOTTKY DIODE
FARNELL PART .1789792
MANUFACTURE:- SANYO

DATASHEET:- SANYO|SB20-03P-TD-E|DIODE,SCHOTTKY,30V,2A,SOT89 | Farnell United Kingdom

 

[OSCAL]

Hi
PNP EPITAXIAL PLANAR TYPE 2SA1736 .. POSSIBLE REPLACEMENT DSA 7004 panasonic
RS components part no:-703 3552 closest match i could find, check out the datasheet:- https://www.electro-tech-online.com/custompdfs/2010/07/0900766b80e23a8a.pdf
Pay close attention to the internal Bias ,linearising resistors in the original.
REGARDS

 

[OSCAL]

Hi
SFPB-54 possible alternative:-
Vishay | Semiconductors | Discretes | Rectifier | Schottky Barrier Rectifiers |B340A-E3/61T
REGARDS