northerner - 2013-11-02 09:11
So I picked up a beater of a 9191 really cheap to repair/mod and have so far repaired and resprayed the back case (see
http://REPLACEMENT ERROR/topic/sharp-gf-refurb-part-1)
Well it was working fine (apart from the deck) when I took it apart but now I'm putting it back together theres no sound!
I cleaned all the switches and left it. When it went back together the fuse blew for seemingly no reason. I checked all the connections and fitted a new fuse. When powered up again there was a weird smell for maybe 20 seconds but then it went. Now it all pretends to work ie lights come on, vu meters move etc but there's just no sound.
Cleaned the record bar and headphone socket again but still nothing.
Nothing looks burnt out or bulging/crumbling so I'm at a loss now. Any ideas?
electronic component has fried......i had exactly the same issue with a 777 once and one of the main amp chips had blown.......
Check for blackening round the output heat sinks si
I had a feeling something had cooked, I'll have a look see...thanks Dave
Si
Look carefully at the ic chip in the amp.... They are normally black and will not stand out as being blown!
If it has blown it will give the appearance of being swollen!
You have to look real close
Good luck bro
If its the amp chip then where do I get a new one from?...I know my basic servicing and am pretty handy with casing repair but know sod all about electronics lol
Si
Give me the chip code and I may be able to get you one
I posted a reply here but it went to mod to allow it...
Try again...
Si this could be a problem with many things. Depending on what shorted when you put it back together.Get someone to look at it for you and do some troubleshooting before you desolder or mess with anything. There is a chance you are right but there is also a massive chance it is something else.
Hope you get this fixed without too much bother Si! (that is not needing another yet another GF9191 parts box
) Just out of interest, where do you buy vintage ICs? is it RS or CPC for example?
Most of the ones I have needed have been from Little diode, a shop down south. They sell on ebay but also have an online shop.
thanks docs, like you say though its not just a matter of replacing a fried part, you need to find what cooked it in the first place!
if it was working before you took it to bits i would make sure all plugs and such are in the correct places si .
Hi Si
A while ago you posted a Pdf scan of the 9191 manual. Unfortunately I can't view it or download it without locking up my antique computer!! If you could PM me the file (or just the circuit diagram) I will look into your problem. Can't remember if the 9191 has more than one fuse in it, if it has that would be a good pointer. The points that smeats and deliverence makes are valid ones. We have to determine what has fried, might not be the amp chip, may be the section of the power supply related to the amp, or may be both.
Thanks for the input chaps!
In view of the advice decided that as it may take plenty time/skill to diagnose the fault plus I've already spent a fair few hours on this bust up ten quid box that I'm modding I've gone to plan B instead
Taken everything back again and out and set aside for parts.
Fitted a powerful Bang and Olufsen amp and am now working on the front and top. Deck door was busted...hairline cracks all over the front...so out it comes and an iPod dock is going in...if I can't get it like new I'm gonna create a monster instead lol!!!!
It'll either be awesome or awful but I'm having a blast doing it...got the dremel working overtime lol
Already tested the sound with the existing speakers and it sounds very promising
Oh and obviously there's a bucket load of LEDs going in too
Thanks for the offer Seb that's really good of you
Originally Posted by Northerner:
Thanks for the offer Seb that's really good of you
No worries mate
plan B sounds good! plus a cheeky little speaker upgrade perhaps!
Well there's loads of spare room in there now...the amp is tiny...so I can try different speakers to see what difference it makes...got a few knocking around so we'll see
Originally Posted by Northerner:
Well there's loads of spare room in there now...the amp is tiny...so I can try different speakers to see what difference it makes...got a few knocking around so we'll see
Hi Si, that's a shame on the amp board blowing. Do all the Vu meters and phono in still work with the new board?
Neil the whole chassis is out...just working on the casing with brand new amp with line in only...going for an unsympathetic restoration this time lol
Wheredid you get the B&O amp from Si?
The amp was brand new and a freebie from my brother in law who's an electronic engineer for Marshall Amps...he does all the bespoke one off amps for rock gods lol...Slash has one of his. He's schmoozed with lots of famous rocker. He even gets paid to go to big gigs and festivals ...jammy git. You'd think he'd be an awesome resource with this hobby but he's always too busy unfortunately
He was going to rebuild the power supply for my GF9000 but that was months and months ago. He's got a few of these amps in his lab so he bunged one in the post to me
Hi Si - thinking of a good 9191 mod for your new project, if you can get an iphone dock connection so the phone can mount horizontal in the place where tape would normally sit, then load up DeliTape app or similar, it would look great with tape image whiring away and sound blasting through your new amp ... you could also play radio this way and have true portable if you are still able to run your amp off batteries in the back ... food for thought :-)
Yeh tried a few of these apps they look cool...trouble is I use Spotify most of the time rather than music on my iPhone. I toyed with different ways of doing a dock but I didn't want it to just fit my current phone so in the end I've gone with plan C or D or Q...not sure where I'm up to now I keep changing it!
Had a day off so casing all repaired now, sanded and primed...gonna have a go at painting something on the front...just hope my painting skills are up to it...I can always respray it if it goes wrong
Originally Posted by Northerner:
The amp was brand new and a freebie from my brother in law who's an electronic engineer for Marshall Amps...he does all the bespoke one off amps for rock gods lol...Slash has one of his. He's schmoozed with lots of famous rocker. He even gets paid to go to big gigs and festivals ...jammy git. You'd think he'd be an awesome resource with this hobby but he's always too busy unfortunately
He was going to rebuild the power supply for my GF9000 but that was months and months ago. He's got a few of these amps in his lab so he bunged one in the post to me
That sounds great, pro quality amp ehh; your going to end up with a very special GF-9191!
Looking forward to pics of your finished handiwork - sounds like a fun project :-)
Si in all honesty it could be anything! Without a proper diagnosis of what it is you might be clutching at straws. I suggest you get it looked at before doing anything.
