Sherwood ES-5030R schematics needed..

[Junm]

Hi diy friends....I've bought a unit of sherwood es-5030r from a local junkshop for 10 usd equiv. it looks clean and no severe scratches....when i opened it it seem that some fuse are missing and no rating is indicated on the board...its a surround a/v amplifier...3 channel using STK400-090 chip as amplifier...

Can anybody share me the schematics of this model...i've search the net but no success in getting one...there are available for sale but only owners manual....thanks in advance

 

[Junm]

It seems that nobody has the service manual or schematics of this model. Is Sherwood made in the U.S? since the components used are not that good, samwha capacitors and Kia made Opamps.

I had replaced the fuses with low values 1A, upon power on, no fuse blows but the stand by trafo is working and the power led lit and the 6 equalizer mode led lit, pressing the button will not turn on the main trafo since it is triggered by a relay. Anybody has an idea? I can't find schematics so I'm tracing it manually.

your help is very much appreciated....

 

[Junm]

Finally got hold of the service manual and found out the problem. Just replaced 2 small over heated trannies and bingo!..I got a Digital surround processor at 10 USD worth plus a dollar worth of parts....not bad..

Here is the faulty ckt board and the system..Sherwoord DSP, 6R2p Tube amp on old pioneer chassis and Luxman Hybrid LV103...

 

[jadesoye]

I have sound output problem with the same device. I replaced the stk400-090. Now signal is input to KIA4559 but no output. I have ordered for KIA4559S to see if the problem will be solved by replace the ic.

I will appreciate any input.

 

[gennaro88]

hello even I myself amplifier, which transistors have replaced thanks.