Sherwood AD-2220 CP smokey resistors

[Noobomatic]

Well i have a sherwood ad-2220 cp amplifier with completely fried resistors (to the point where thers n way in hell your gonna tell the resistance) i have posted it on other forums but havenbt even had a reply :\ i cant be the onlyone with this amp in the universe. annywho, first off is the amplification stage

i need the codes for the following

R401R__
R401L__ both are 1watt resistors i belive

(protect board)
R329R --- appear to both be 1/2 watt resisters or 1/4
R329L

Any help would be welcomed ill post pictures in minutes

[Noobomatic]

Re: Sherwood AD-2220 CP smokey resistors

turns out i cant upload pics, will try again later

[Noobomatic]

Re: Sherwood AD-2220 CP smokey resistors

finaly it works! hope you guys can help me out just a little

[T30M31]

Re: Sherwood AD-2220 CP smokey resistors

R401R and R401L look like 22 ohm metal film resistors. R401R doesn't look too badly damaged so measure it with an ohmmeter and see if it is close to 22 ohms. It could be 220 ohms but I think the third band is black and not brown.

You will probably need a schematic for the other resistors unless someone on this forum has access to this amp. The only service manual I have been able to locate is for sale on "AnalogAlley.com". I don't know anything about that service.

I did locate one of these amps for sale on EBay by someone in Australia. You might check with them and see if they would take the cover off and give you a good photo to help identify the resistors.

[Noobomatic]

Re: Sherwood AD-2220 CP smokey resistors

hey thanks for taking the time to reply to me, ill measure that resistor before i post this reply and ill take a look at that ad and message the seller thank you & please as usual if anyone else has ideas let me know? 2009k on the resistor unfortuantley i think its kaput ..i could run higher resistors without damaging the circuit right?

[T30M31]

Re: Sherwood AD-2220 CP smokey resistors

..i could run higher resistors without damaging the circuit right?

Not necessarily. This is the protection board so if the resistors are not sized correctly you may damage the amplifier output circuit if you crank up the volume to high or have a speaker problem.

[JJR]

Re: Sherwood AD-2220 CP smokey resistors

http://www.ebay.co.uk/itm/SHERWOOD-A...item43c34eaa9f

(In Canada)

[Noobomatic]

Re: Sherwood AD-2220 CP smokey resistors

i was afraid of that happening T30 i have to head to bed its 2:05 am with study work and ebay & life im dead tired!

[Noobomatic]

Re: Sherwood AD-2220 CP smokey resistors

ive paid for the service manual from canada and so we'll see how that goes!

[Agent24]

Re: Sherwood AD-2220 CP smokey resistors

This might help: http://www.electricaltechnology.org/...sistor-by.html but the service manual will be a better bet!

[Noobomatic]

Re: Sherwood AD-2220 CP smokey resistors

Well it turns out i have won an old sherwood amp on ebay & bought the service manual from ebay, im sure i can find nearly all the parts i need for the amp's to fix them both up hopefully and make a few bucks off them, for now its onto the next item!

Thank you gent's for all of your help ill update the thread once all the parts are changed

[Noobomatic]

Re: Sherwood AD-2220 CP smokey resistors

I just wanted to finish this thread, it turns out that on one of the amplifiers the 2 stkxxxx chips are shorted and need replacing and the second amplifier one of the chips is shorted but also had some kind of shonkey repair, ill stack them up put them away and fix them one day, I have too much study to do!!

[grafton26]

Re: Sherwood AD-2220 CP smokey resistors

Hi mate , I too have some burnt resistors on the protect board of this model amp , is there and chance you could scan the schematic for me ? I know that should be all that is wrong with mine as the amp was stored in a garage and the last owner didn't cover it up and as a result the rats and mice peed on it and then the next time he got it out to use it the smoke came out and that was it , he passed it on to me as he was going to ditch it
Allan

[grafton26]

Re: Sherwood AD-2220 CP smokey resistors

Hi Noobmatic I don't know if you have yours sorted or not but your picture has given me enough to sort mine out I have included a couple of images to assist others seeking this info as there is very little available for this amp
R329L is as follows orange , orange , Brown, gold , I am assuming the R329R is the same value
the R401R and R401L are red, red, red, gold ( they are also 1/2 watt resistors )

[R_J]

Re: Sherwood AD-2220 CP smokey resistors

I did some searching and it looks like the LXI AM 4023 is the same amp, so maybe there is a schematic for it somwhere.

[grafton26]

Re: Sherwood AD-2220 CP smokey resistors

there is , but it isn't free , the price was around $12 US

[R_J]

Re: Sherwood AD-2220 CP smokey resistors

[grafton26]

Re: Sherwood AD-2220 CP smokey resistors

I did some searching and it looks like the LXI AM 4023 is the same amp, so maybe there is a schematic for it somwhere.

there is also one made by INKEL that is the same unit internally