Hi,i did a search and i`ve just read some stuff about tape deck problems on the J1 aka intersound j747..tape decks playing very very fast,i hear from reading beatbox`s thread and others,it looks like its a very common problem with this box,i have`nt got the testers or equipment to test any of it,so i was going to take it to my friends shop and let him sort it out,but...i may just brave it out and have a gander myself,but i dont want to touch it until i can find out exactly what to look for..
Any help would be appretiated

so...anyone know how to fix j1 speed prob ??
if this helps,here`s an old thread i found..

http://stereo2go.com/eve/forum...731043805#2731043805

Took it to my repair shop today,he checked it out while i was there,he found a transistor that was short circuit/burned out,he found the right one in his spare bits so he changed it,but the decks are still the same,he checked the voltage to the motors,he said the voltage seems pretty normal,so he said i should try changing the motors,he said its got cheap n nasty motors in it,that has a speed regulator built in the moter itself,he said that goes mental and sets the motor off at wild speed,so i gotta look for 2x 12v/ccw/1600rpm motor,well i will have to try one first to see if that is the problem..looks like its gunna be quite a big job..might buy another intersound or J1,anyone selling one ??
oh yes,the on/off button is short circuit so the box is switched on all the time,so i have to get a new on/off switch..

Right....
I fixed the ON/OFF button now,also fixed the alarm..just those damm tape decks..grrrr

It's OK to talk to yourself GETTOMAN, just make sure you don't answer!!!

Keep plugging away at it, you'll get it fixed!!!

'NUFF SAID

Hey Ghettoman,

I think the tech guy who looked at the unit doesn't know what he's talking about.
These motors have an external feedback speed control cicuit.

Before you go and spend usless money on 2 motors, try testing the 4 speed contol potentiometers to see if there o/c (open circuit). I fixed a few of these units and this is a common problem. They corrod and go o/c.
The reason the motors are running at full speed is because there's no feedback. As far as I can remember they should measure 1kohm and 500ohm. Been a while since i worked on the last one. The value is stamped on them though.
If its not the potis then its probably the HIGH SPEED switch faulty or not connected.

I'll see if I can dig up some pics for you so you know where to look on the pcb.
Do you have a multimeter anyway?
Let me know if you need more help.

Cheers. Roddy

Hi roddy,thanks for the info..i`ve been on it half the day..yes you are right,the motors are ok,the 2 500k VRs have had it,i need 2 new ones now to replace them..i also had to change the belts because they were shot but i ran out of the size i need for deck A,so that will have to wait along with the 2 VR`s,i also found that the new transister the tech guy put in was`nt right,because there was another transistor next to it kept getting hot when i pressed play,so i went digging about in my bits and found the exact transistor,fitted that,no more hot transistor..
This box is starting to be no fun..actually,i think they are a bit junk..very cheap quality..i`ve wanted one of these for 20 years and now i`ve got one,i`ve done nothing but work on it,the back has`nt been on since i got it..oh well,i`ll just have to carry on,i`ll get there in the end..and hopefully,i`ll be able to enjoy it one day..