Need help identifying components please.

[William_Wallace]

I have a Creative Labs Inspire 6700 6.1 speaker system for my computer. I turned it on the other day and nothing. No power light or sound. Tested the power adapter and its ok. When i opened the Subwoofer up, I noticed the circuit board had a few burnt out components on it.

Can anyone help me identify what components i need to order up (eg from Maplin) as im not full up to speed on this yet. My soldering and de-soldering skills are fine though...lol.
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The Capacitor is marked: RB 85degreesC
25V 100uF.
11mm high and 6m diameter, black coloured.
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The Transistor is marked H945
P
2F 2
5mm high and 4mm diameter, black coloured also.
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Resistor 1 is marked (i think) green, blue, brown, gold, on a tan base colour.
Resistor 2 is marked (i think) brown, red, red, gold, on a tan base colour.

Both are 3mm long and 1mm diameter.
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I have a link to my burnt out circuit board below:
http://www.williamwallace1.f2s.com/circuit.htm

Any help would be greatly appreciated to help me repair this

[Bendone]

Hi
Don’t think about the colors (values) of the resistances, be sure.
The resistor 1 is 560 Ohms ½ Watt
Resistor 2 is 1.2 Kilo Ohms ½ Watt
The transistor (H945P) and the capacitor is electrolytic (100 micro ferrite 25 Volts) …… you already know.
Changing these may not solve the problem. The cause of this burnout has to be determined. Just check if your circuit board has a voltage regulator that would be a black flat component, vertically mounted (probably on a metal plate with a screw.... not necessarily), with 3 lags soldered to the board and with numbers starting with XX78?? (any thing XX could be letters followed by 78 and then if 05 it +5 volts, if 09 it +9 volts and if 12 it +12 volts) For sure this is gone bad. Replace this too.

Good luck.

[Guest]

Thanks a lot for the assistance. Still kind of stuck as Maplins codes are different to anything i need, ie no H945P transistors.

Gonna keep searching, maybe even try RS to see if i can find anything.

[Guest]

I need to now the real name for the component called H945P (2E4) existent in a Creative 6700, because I can't find the datasheet.

Thanks for your helps!

[Guest]

H945 is made by Hitachi. Should be able to use generis 2SC945 instead

[Guest]

I have the same problem, but there is no burnet components, i tested the regulator there is something strange, its input is 13.5 V AC, and output is 18 V DC(mounted on board, which is higher than usual), 12.5 V DC whenremoved from the board. I also checked for all the power of the ics, i found that all M51132L have no power, when i traced this fault back it lead me to the same area that u have the components burnt. i am going to change these componets maybe it solvs the problem.

[Pascal GAYDON]

Thanks for your help. I could fix the problem followings your reflections.
Efectively this transistor Q5 (H945P) had its Base-Emitter junction cut.
I've replace it by a stronger one : BD137. This transistor gives
10,62 Volts to all IC's M51132L (Volumes controls), reducing the main 19-20 Volts. Because a lot of heating, I've installed it on the dissipating aluminium plate, on the free of power IC's side. You need to drill a 3mm hole and to put a heating transfer isolator because the collector of the BD137 is not isolated and arrives on its rear metallic face. Don't forget it cause it would create a direct short-circuit on the main 20Vdc.
This solution is reliable after big testing.

[Guest]

Hi,

A 6600 system a customer has experienced a similar problem.

Q5 - a H945 transistor (2SC945, 2SC1815) went open. Some minor hear marks are on the PCB, but otherwise no burnt/obvious components.

The resistor values in the other replies are not correct. Correct values are:

R10,11 - 5R6 (5.6 ohms) Green, Blue, Gold
R12 - 1K2 (1.2 Kohms) Brown, Red, Red

Hope this helps,
Ian
([email protected])

[Fiveblades]

I want to thank you guys for bringing me up to date.
Fixed my set now, but used a simular c945 from a old pc power supply.

Recycle rocks !

[Guest]